FCL/sf/os/persistentdata: comparison persistentstorage/sqlite3api/SQLite/vdbe.c

equal deleted inserted replaced

--1:000000000000
+:08ec8eefde2f
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** The code in this file implements execution method of the
+** Virtual Database Engine (VDBE).  A separate file ("vdbeaux.c")
+** handles housekeeping details such as creating and deleting
+** VDBE instances.  This file is solely interested in executing
+** the VDBE program.
+**
+** In the external interface, an "sqlite3_stmt*" is an opaque pointer
+** to a VDBE.
+**
+** The SQL parser generates a program which is then executed by
+** the VDBE to do the work of the SQL statement.  VDBE programs are
+** similar in form to assembly language.  The program consists of
+** a linear sequence of operations.  Each operation has an opcode
+** and 5 operands.  Operands P1, P2, and P3 are integers.  Operand P4
+** is a null-terminated string.  Operand P5 is an unsigned character.
+** Few opcodes use all 5 operands.
+**
+** Computation results are stored on a set of registers numbered beginning
+** with 1 and going up to Vdbe.nMem.  Each register can store
+** either an integer, a null-terminated string, a floating point
+** number, or the SQL "NULL" value.  An implicit conversion from one
+** type to the other occurs as necessary.
+**
+** Most of the code in this file is taken up by the sqlite3VdbeExec()
+** function which does the work of interpreting a VDBE program.
+** But other routines are also provided to help in building up
+** a program instruction by instruction.
+**
+** Various scripts scan this source file in order to generate HTML
+** documentation, headers files, or other derived files.  The formatting
+** of the code in this file is, therefore, important.  See other comments
+** in this file for details.  If in doubt, do not deviate from existing
+** commenting and indentation practices when changing or adding code.
+**
+** $Id: vdbe.c,v 1.779 2008/09/22 06:13:32 danielk1977 Exp $
+*/
+#include "sqliteInt.h"
+#include <ctype.h>
+#include "vdbeInt.h"
+/*
+** The following global variable is incremented every time a cursor
+** moves, either by the OP_MoveXX, OP_Next, or OP_Prev opcodes.  The test
+** procedures use this information to make sure that indices are
+** working correctly.  This variable has no function other than to
+** help verify the correct operation of the library.
+*/
+#ifdef SQLITE_TEST
+int sqlite3_search_count = 0;
+#endif
+/*
+** When this global variable is positive, it gets decremented once before
+** each instruction in the VDBE.  When reaches zero, the u1.isInterrupted
+** field of the sqlite3 structure is set in order to simulate and interrupt.
+**
+** This facility is used for testing purposes only.  It does not function
+** in an ordinary build.
+*/
+#ifdef SQLITE_TEST
+int sqlite3_interrupt_count = 0;
+#endif
+/*
+** The next global variable is incremented each type the OP_Sort opcode
+** is executed.  The test procedures use this information to make sure that
+** sorting is occurring or not occurring at appropriate times.   This variable
+** has no function other than to help verify the correct operation of the
+** library.
+*/
+#ifdef SQLITE_TEST
+int sqlite3_sort_count = 0;
+#endif
+/*
+** The next global variable records the size of the largest MEM_Blob
+** or MEM_Str that has been used by a VDBE opcode.  The test procedures
+** use this information to make sure that the zero-blob functionality
+** is working correctly.   This variable has no function other than to
+** help verify the correct operation of the library.
+*/
+#ifdef SQLITE_TEST
+int sqlite3_max_blobsize = 0;
+static void updateMaxBlobsize(Mem *p){
+if( (p->flags & (MEM_Str|MEM_Blob))!=0 && p->n>sqlite3_max_blobsize ){
+sqlite3_max_blobsize = p->n;
+}
+}
+#endif
+/*
+** Test a register to see if it exceeds the current maximum blob size.
+** If it does, record the new maximum blob size.
+*/
+#if defined(SQLITE_TEST) && !defined(SQLITE_OMIT_BUILTIN_TEST)
+# define UPDATE_MAX_BLOBSIZE(P)  updateMaxBlobsize(P)
+#else
+# define UPDATE_MAX_BLOBSIZE(P)
+#endif
+/*
+** Convert the given register into a string if it isn't one
+** already. Return non-zero if a malloc() fails.
+*/
+#define Stringify(P, enc) \
+if(((P)->flags&(MEM_Str|MEM_Blob))==0 && sqlite3VdbeMemStringify(P,enc)) \
+{ goto no_mem; }
+/*
+** An ephemeral string value (signified by the MEM_Ephem flag) contains
+** a pointer to a dynamically allocated string where some other entity
+** is responsible for deallocating that string.  Because the register
+** does not control the string, it might be deleted without the register
+** knowing it.
+**
+** This routine converts an ephemeral string into a dynamically allocated
+** string that the register itself controls.  In other words, it
+** converts an MEM_Ephem string into an MEM_Dyn string.
+*/
+#define Deephemeralize(P) \
+if( ((P)->flags&MEM_Ephem)!=0 \
+&& sqlite3VdbeMemMakeWriteable(P) ){ goto no_mem;}
+/*
+** Call sqlite3VdbeMemExpandBlob() on the supplied value (type Mem*)
+** P if required.
+*/
+#define ExpandBlob(P) (((P)->flags&MEM_Zero)?sqlite3VdbeMemExpandBlob(P):0)
+/*
+** Argument pMem points at a register that will be passed to a
+** user-defined function or returned to the user as the result of a query.
+** The second argument, 'db_enc' is the text encoding used by the vdbe for
+** register variables.  This routine sets the pMem->enc and pMem->type
+** variables used by the sqlite3_value_*() routines.
+*/
+#define storeTypeInfo(A,B) _storeTypeInfo(A)
+static void _storeTypeInfo(Mem *pMem){
+int flags = pMem->flags;
+if( flags & MEM_Null ){
+pMem->type = SQLITE_NULL;
+}
+else if( flags & MEM_Int ){
+pMem->type = SQLITE_INTEGER;
+}
+else if( flags & MEM_Real ){
+pMem->type = SQLITE_FLOAT;
+}
+else if( flags & MEM_Str ){
+pMem->type = SQLITE_TEXT;
+}else{
+pMem->type = SQLITE_BLOB;
+}
+}
+/*
+** Properties of opcodes.  The OPFLG_INITIALIZER macro is
+** created by mkopcodeh.awk during compilation.  Data is obtained
+** from the comments following the "case OP_xxxx:" statements in
+** this file.
+*/
+static const unsigned char opcodeProperty[] = OPFLG_INITIALIZER;
+/*
+** Return true if an opcode has any of the OPFLG_xxx properties
+** specified by mask.
+*/
+int sqlite3VdbeOpcodeHasProperty(int opcode, int mask){
+assert( opcode>0 && opcode<sizeof(opcodeProperty) );
+return (opcodeProperty[opcode]&mask)!=0;
+}
+/*
+** Allocate cursor number iCur.  Return a pointer to it.  Return NULL
+** if we run out of memory.
+*/
+static Cursor *allocateCursor(
+Vdbe *p,
+int iCur,
+Op *pOp,
+int iDb,
+int isBtreeCursor
+){
+/* Find the memory cell that will be used to store the blob of memory
+** required for this Cursor structure. It is convenient to use a
+** vdbe memory cell to manage the memory allocation required for a
+** Cursor structure for the following reasons:
+**
+**   * Sometimes cursor numbers are used for a couple of different
+**     purposes in a vdbe program. The different uses might require
+**     different sized allocations. Memory cells provide growable
+**     allocations.
+**
+**   * When using ENABLE_MEMORY_MANAGEMENT, memory cell buffers can
+**     be freed lazily via the sqlite3_release_memory() API. This
+**     minimizes the number of malloc calls made by the system.
+**
+** Memory cells for cursors are allocated at the top of the address
+** space. Memory cell (p->nMem) corresponds to cursor 0. Space for
+** cursor 1 is managed by memory cell (p->nMem-1), etc.
+*/
+Mem *pMem = &p->aMem[p->nMem-iCur];
+int nByte;
+Cursor *pCx = 0;
+/* If the opcode of pOp is OP_SetNumColumns, then pOp->p2 contains
+** the number of fields in the records contained in the table or
+** index being opened. Use this to reserve space for the
+** Cursor.aType[] array.
+*/
+int nField = 0;
+if( pOp->opcode==OP_SetNumColumns || pOp->opcode==OP_OpenEphemeral ){
+nField = pOp->p2;
+}
+nByte =
+sizeof(Cursor) +
+(isBtreeCursor?sqlite3BtreeCursorSize():0) +
+2*nField*sizeof(u32);
+assert( iCur<p->nCursor );
+if( p->apCsr[iCur] ){
+sqlite3VdbeFreeCursor(p, p->apCsr[iCur]);
+p->apCsr[iCur] = 0;
+}
+if( SQLITE_OK==sqlite3VdbeMemGrow(pMem, nByte, 0) ){
+p->apCsr[iCur] = pCx = (Cursor *)pMem->z;
+memset(pMem->z, 0, nByte);
+pCx->iDb = iDb;
+pCx->nField = nField;
+if( nField ){
+pCx->aType = (u32 *)&pMem->z[sizeof(Cursor)];
+}
+if( isBtreeCursor ){
+pCx->pCursor = (BtCursor *)&pMem->z[sizeof(Cursor)+2*nField*sizeof(u32)];
+}
+}
+return pCx;
+}
+/*
+** Try to convert a value into a numeric representation if we can
+** do so without loss of information.  In other words, if the string
+** looks like a number, convert it into a number.  If it does not
+** look like a number, leave it alone.
+*/
+static void applyNumericAffinity(Mem *pRec){
+if( (pRec->flags & (MEM_Real|MEM_Int))==0 ){
+int realnum;
+sqlite3VdbeMemNulTerminate(pRec);
+if( (pRec->flags&MEM_Str)
+&& sqlite3IsNumber(pRec->z, &realnum, pRec->enc) ){
+i64 value;
+sqlite3VdbeChangeEncoding(pRec, SQLITE_UTF8);
+if( !realnum && sqlite3Atoi64(pRec->z, &value) ){
+pRec->u.i = value;
+MemSetTypeFlag(pRec, MEM_Int);
+}else{
+sqlite3VdbeMemRealify(pRec);
+}
+}
+}
+}
+/*
+** Processing is determine by the affinity parameter:
+**
+** SQLITE_AFF_INTEGER:
+** SQLITE_AFF_REAL:
+** SQLITE_AFF_NUMERIC:
+**    Try to convert pRec to an integer representation or a
+**    floating-point representation if an integer representation
+**    is not possible.  Note that the integer representation is
+**    always preferred, even if the affinity is REAL, because
+**    an integer representation is more space efficient on disk.
+**
+** SQLITE_AFF_TEXT:
+**    Convert pRec to a text representation.
+**
+** SQLITE_AFF_NONE:
+**    No-op.  pRec is unchanged.
+*/
+static void applyAffinity(
+Mem *pRec,          /* The value to apply affinity to */
+char affinity,      /* The affinity to be applied */
+u8 enc              /* Use this text encoding */
+){
+if( affinity==SQLITE_AFF_TEXT ){
+/* Only attempt the conversion to TEXT if there is an integer or real
+** representation (blob and NULL do not get converted) but no string
+** representation.
+*/
+if( 0==(pRec->flags&MEM_Str) && (pRec->flags&(MEM_Real|MEM_Int)) ){
+sqlite3VdbeMemStringify(pRec, enc);
+}
+pRec->flags &= ~(MEM_Real|MEM_Int);
+}else if( affinity!=SQLITE_AFF_NONE ){
+assert( affinity==SQLITE_AFF_INTEGER || affinity==SQLITE_AFF_REAL
+|| affinity==SQLITE_AFF_NUMERIC );
+applyNumericAffinity(pRec);
+if( pRec->flags & MEM_Real ){
+sqlite3VdbeIntegerAffinity(pRec);
+}
+}
+}
+/*
+** Try to convert the type of a function argument or a result column
+** into a numeric representation.  Use either INTEGER or REAL whichever
+** is appropriate.  But only do the conversion if it is possible without
+** loss of information and return the revised type of the argument.
+**
+** This is an EXPERIMENTAL api and is subject to change or removal.
+*/
+SQLITE_EXPORT int sqlite3_value_numeric_type(sqlite3_value *pVal){
+Mem *pMem = (Mem*)pVal;
+applyNumericAffinity(pMem);
+storeTypeInfo(pMem, 0);
+return pMem->type;
+}
+/*
+** Exported version of applyAffinity(). This one works on sqlite3_value*,
+** not the internal Mem* type.
+*/
+void sqlite3ValueApplyAffinity(
+sqlite3_value *pVal,
+u8 affinity,
+u8 enc
+){
+applyAffinity((Mem *)pVal, affinity, enc);
+}
+#ifdef SQLITE_DEBUG
+/*
+** Write a nice string representation of the contents of cell pMem
+** into buffer zBuf, length nBuf.
+*/
+void sqlite3VdbeMemPrettyPrint(Mem *pMem, char *zBuf){
+char *zCsr = zBuf;
+int f = pMem->flags;
+static const char *const encnames[] = {"(X)", "(8)", "(16LE)", "(16BE)"};
+if( f&MEM_Blob ){
+int i;
+char c;
+if( f & MEM_Dyn ){
+c = 'z';
+assert( (f & (MEM_Static|MEM_Ephem))==0 );
+}else if( f & MEM_Static ){
+c = 't';
+assert( (f & (MEM_Dyn|MEM_Ephem))==0 );
+}else if( f & MEM_Ephem ){
+c = 'e';
+assert( (f & (MEM_Static|MEM_Dyn))==0 );
+}else{
+c = 's';
+}
+sqlite3_snprintf(100, zCsr, "%c", c);
+zCsr += strlen(zCsr);
+sqlite3_snprintf(100, zCsr, "%d[", pMem->n);
+zCsr += strlen(zCsr);
+for(i=0; i<16 && i<pMem->n; i++){
+sqlite3_snprintf(100, zCsr, "%02X", ((int)pMem->z[i] & 0xFF));
+zCsr += strlen(zCsr);
+}
+for(i=0; i<16 && i<pMem->n; i++){
+char z = pMem->z[i];
+if( z<32 || z>126 ) *zCsr++ = '.';
+else *zCsr++ = z;
+}
+sqlite3_snprintf(100, zCsr, "]%s", encnames[pMem->enc]);
+zCsr += strlen(zCsr);
+if( f & MEM_Zero ){
+sqlite3_snprintf(100, zCsr,"+%lldz",pMem->u.i);
+zCsr += strlen(zCsr);
+}
+*zCsr = '\0';
+}else if( f & MEM_Str ){
+int j, k;
+zBuf[0] = ' ';
+if( f & MEM_Dyn ){
+zBuf[1] = 'z';
+assert( (f & (MEM_Static|MEM_Ephem))==0 );
+}else if( f & MEM_Static ){
+zBuf[1] = 't';
+assert( (f & (MEM_Dyn|MEM_Ephem))==0 );
+}else if( f & MEM_Ephem ){
+zBuf[1] = 'e';
+assert( (f & (MEM_Static|MEM_Dyn))==0 );
+}else{
+zBuf[1] = 's';
+}
+k = 2;
+sqlite3_snprintf(100, &zBuf[k], "%d", pMem->n);
+k += strlen(&zBuf[k]);
+zBuf[k++] = '[';
+for(j=0; j<15 && j<pMem->n; j++){
+u8 c = pMem->z[j];
+if( c>=0x20 && c<0x7f ){
+zBuf[k++] = c;
+}else{
+zBuf[k++] = '.';
+}
+}
+zBuf[k++] = ']';
+sqlite3_snprintf(100,&zBuf[k], encnames[pMem->enc]);
+k += strlen(&zBuf[k]);
+zBuf[k++] = 0;
+}
+}
+#endif
+#ifdef SQLITE_DEBUG
+/*
+** Print the value of a register for tracing purposes:
+*/
+static void memTracePrint(FILE *out, Mem *p){
+if( p->flags & MEM_Null ){
+fprintf(out, " NULL");
+}else if( (p->flags & (MEM_Int|MEM_Str))==(MEM_Int|MEM_Str) ){
+fprintf(out, " si:%lld", p->u.i);
+}else if( p->flags & MEM_Int ){
+fprintf(out, " i:%lld", p->u.i);
+}else if( p->flags & MEM_Real ){
+fprintf(out, " r:%g", p->r);
+}else{
+char zBuf[200];
+sqlite3VdbeMemPrettyPrint(p, zBuf);
+fprintf(out, " ");
+fprintf(out, "%s", zBuf);
+}
+}
+static void registerTrace(FILE *out, int iReg, Mem *p){
+fprintf(out, "REG[%d] = ", iReg);
+memTracePrint(out, p);
+fprintf(out, "\n");
+}
+#endif
+#ifdef SQLITE_DEBUG
+#  define REGISTER_TRACE(R,M) if(p->trace)registerTrace(p->trace,R,M)
+#else
+#  define REGISTER_TRACE(R,M)
+#endif
+#ifdef VDBE_PROFILE
+/*
+** hwtime.h contains inline assembler code for implementing
+** high-performance timing routines.
+*/
+#include "hwtime.h"
+#endif
+/*
+** The CHECK_FOR_INTERRUPT macro defined here looks to see if the
+** sqlite3_interrupt() routine has been called.  If it has been, then
+** processing of the VDBE program is interrupted.
+**
+** This macro added to every instruction that does a jump in order to
+** implement a loop.  This test used to be on every single instruction,
+** but that meant we more testing that we needed.  By only testing the
+** flag on jump instructions, we get a (small) speed improvement.
+*/
+#define CHECK_FOR_INTERRUPT \
+if( db->u1.isInterrupted ) goto abort_due_to_interrupt;
+#ifdef SQLITE_DEBUG
+static int fileExists(sqlite3 *db, const char *zFile){
+int res = 0;
+int rc = SQLITE_OK;
+#ifdef SQLITE_TEST
+/* If we are currently testing IO errors, then do not call OsAccess() to
+** test for the presence of zFile. This is because any IO error that
+** occurs here will not be reported, causing the test to fail.
+*/
+extern int sqlite3_io_error_pending;
+if( sqlite3_io_error_pending<=0 )
+#endif
+rc = sqlite3OsAccess(db->pVfs, zFile, SQLITE_ACCESS_EXISTS, &res);
+return (res && rc==SQLITE_OK);
+}
+#endif
+/*
+** Execute as much of a VDBE program as we can then return.
+**
+** sqlite3VdbeMakeReady() must be called before this routine in order to
+** close the program with a final OP_Halt and to set up the callbacks
+** and the error message pointer.
+**
+** Whenever a row or result data is available, this routine will either
+** invoke the result callback (if there is one) or return with
+** SQLITE_ROW.
+**
+** If an attempt is made to open a locked database, then this routine
+** will either invoke the busy callback (if there is one) or it will
+** return SQLITE_BUSY.
+**
+** If an error occurs, an error message is written to memory obtained
+** from sqlite3_malloc() and p->zErrMsg is made to point to that memory.
+** The error code is stored in p->rc and this routine returns SQLITE_ERROR.
+**
+** If the callback ever returns non-zero, then the program exits
+** immediately.  There will be no error message but the p->rc field is
+** set to SQLITE_ABORT and this routine will return SQLITE_ERROR.
+**
+** A memory allocation error causes p->rc to be set to SQLITE_NOMEM and this
+** routine to return SQLITE_ERROR.
+**
+** Other fatal errors return SQLITE_ERROR.
+**
+** After this routine has finished, sqlite3VdbeFinalize() should be
+** used to clean up the mess that was left behind.
+*/
+int sqlite3VdbeExec(
+Vdbe *p                    /* The VDBE */
+){
+int pc;                    /* The program counter */
+Op *pOp;                   /* Current operation */
+int rc = SQLITE_OK;        /* Value to return */
+sqlite3 *db = p->db;       /* The database */
+u8 encoding = ENC(db);     /* The database encoding */
+Mem *pIn1, *pIn2, *pIn3;   /* Input operands */
+Mem *pOut;                 /* Output operand */
+u8 opProperty;
+int iCompare = 0;          /* Result of last OP_Compare operation */
+int *aPermute = 0;         /* Permuation of columns for OP_Compare */
+#ifdef VDBE_PROFILE
+u64 start;                 /* CPU clock count at start of opcode */
+int origPc;                /* Program counter at start of opcode */
+#endif
+#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
+int nProgressOps = 0;      /* Opcodes executed since progress callback. */
+#endif
+UnpackedRecord aTempRec[16]; /* Space to hold a transient UnpackedRecord */
+assert( p->magic==VDBE_MAGIC_RUN );  /* sqlite3_step() verifies this */
+assert( db->magic==SQLITE_MAGIC_BUSY );
+sqlite3BtreeMutexArrayEnter(&p->aMutex);
+if( p->rc==SQLITE_NOMEM ){
+/* This happens if a malloc() inside a call to sqlite3_column_text() or
+** sqlite3_column_text16() failed.  */
+goto no_mem;
+}
+assert( p->rc==SQLITE_OK || p->rc==SQLITE_BUSY );
+p->rc = SQLITE_OK;
+assert( p->explain==0 );
+p->pResultSet = 0;
+db->busyHandler.nBusy = 0;
+CHECK_FOR_INTERRUPT;
+sqlite3VdbeIOTraceSql(p);
+#ifdef SQLITE_DEBUG
+sqlite3BeginBenignMalloc();
+if( p->pc==0
+&& ((p->db->flags & SQLITE_VdbeListing) || fileExists(db, "vdbe_explain"))
+){
+int i;
+printf("VDBE Program Listing:\n");
+sqlite3VdbePrintSql(p);
+for(i=0; i<p->nOp; i++){
+sqlite3VdbePrintOp(stdout, i, &p->aOp[i]);
+}
+}
+if( fileExists(db, "vdbe_trace") ){
+p->trace = stdout;
+}
+sqlite3EndBenignMalloc();
+#endif
+for(pc=p->pc; rc==SQLITE_OK; pc++){
+assert( pc>=0 && pc<p->nOp );
+if( db->mallocFailed ) goto no_mem;
+#ifdef VDBE_PROFILE
+origPc = pc;
+start = sqlite3Hwtime();
+#endif
+pOp = &p->aOp[pc];
+/* Only allow tracing if SQLITE_DEBUG is defined.
+*/
+#ifdef SQLITE_DEBUG
+if( p->trace ){
+if( pc==0 ){
+printf("VDBE Execution Trace:\n");
+sqlite3VdbePrintSql(p);
+}
+sqlite3VdbePrintOp(p->trace, pc, pOp);
+}
+if( p->trace==0 && pc==0 ){
+sqlite3BeginBenignMalloc();
+if( fileExists(db, "vdbe_sqltrace") ){
+sqlite3VdbePrintSql(p);
+}
+sqlite3EndBenignMalloc();
+}
+#endif
+/* Check to see if we need to simulate an interrupt.  This only happens
+** if we have a special test build.
+*/
+#ifdef SQLITE_TEST
+if( sqlite3_interrupt_count>0 ){
+sqlite3_interrupt_count--;
+if( sqlite3_interrupt_count==0 ){
+sqlite3_interrupt(db);
+}
+}
+#endif
+#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
+/* Call the progress callback if it is configured and the required number
+** of VDBE ops have been executed (either since this invocation of
+** sqlite3VdbeExec() or since last time the progress callback was called).
+** If the progress callback returns non-zero, exit the virtual machine with
+** a return code SQLITE_ABORT.
+*/
+if( db->xProgress ){
+if( db->nProgressOps==nProgressOps ){
+int prc;
+if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
+prc =db->xProgress(db->pProgressArg);
+if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
+if( prc!=0 ){
+rc = SQLITE_INTERRUPT;
+goto vdbe_error_halt;
+}
+nProgressOps = 0;
+}
+nProgressOps++;
+}
+#endif
+/* Do common setup processing for any opcode that is marked
+** with the "out2-prerelease" tag.  Such opcodes have a single
+** output which is specified by the P2 parameter.  The P2 register
+** is initialized to a NULL.
+*/
+opProperty = opcodeProperty[pOp->opcode];
+if( (opProperty & OPFLG_OUT2_PRERELEASE)!=0 ){
+assert( pOp->p2>0 );
+assert( pOp->p2<=p->nMem );
+pOut = &p->aMem[pOp->p2];
+sqlite3VdbeMemReleaseExternal(pOut);
+pOut->flags = MEM_Null;
+}else
+/* Do common setup for opcodes marked with one of the following
+** combinations of properties.
+**
+**           in1
+**           in1 in2
+**           in1 in2 out3
+**           in1 in3
+**
+** Variables pIn1, pIn2, and pIn3 are made to point to appropriate
+** registers for inputs.  Variable pOut points to the output register.
+*/
+if( (opProperty & OPFLG_IN1)!=0 ){
+assert( pOp->p1>0 );
+assert( pOp->p1<=p->nMem );
+pIn1 = &p->aMem[pOp->p1];
+REGISTER_TRACE(pOp->p1, pIn1);
+if( (opProperty & OPFLG_IN2)!=0 ){
+assert( pOp->p2>0 );
+assert( pOp->p2<=p->nMem );
+pIn2 = &p->aMem[pOp->p2];
+REGISTER_TRACE(pOp->p2, pIn2);
+if( (opProperty & OPFLG_OUT3)!=0 ){
+assert( pOp->p3>0 );
+assert( pOp->p3<=p->nMem );
+pOut = &p->aMem[pOp->p3];
+}
+}else if( (opProperty & OPFLG_IN3)!=0 ){
+assert( pOp->p3>0 );
+assert( pOp->p3<=p->nMem );
+pIn3 = &p->aMem[pOp->p3];
+REGISTER_TRACE(pOp->p3, pIn3);
+}
+}else if( (opProperty & OPFLG_IN2)!=0 ){
+assert( pOp->p2>0 );
+assert( pOp->p2<=p->nMem );
+pIn2 = &p->aMem[pOp->p2];
+REGISTER_TRACE(pOp->p2, pIn2);
+}else if( (opProperty & OPFLG_IN3)!=0 ){
+assert( pOp->p3>0 );
+assert( pOp->p3<=p->nMem );
+pIn3 = &p->aMem[pOp->p3];
+REGISTER_TRACE(pOp->p3, pIn3);
+}
+switch( pOp->opcode ){
+/*****************************************************************************
+** What follows is a massive switch statement where each case implements a
+** separate instruction in the virtual machine.  If we follow the usual
+** indentation conventions, each case should be indented by 6 spaces.  But
+** that is a lot of wasted space on the left margin.  So the code within
+** the switch statement will break with convention and be flush-left. Another
+** big comment (similar to this one) will mark the point in the code where
+** we transition back to normal indentation.
+**
+** The formatting of each case is important.  The makefile for SQLite
+** generates two C files "opcodes.h" and "opcodes.c" by scanning this
+** file looking for lines that begin with "case OP_".  The opcodes.h files
+** will be filled with #defines that give unique integer values to each
+** opcode and the opcodes.c file is filled with an array of strings where
+** each string is the symbolic name for the corresponding opcode.  If the
+** case statement is followed by a comment of the form "/# same as ... #/"
+** that comment is used to determine the particular value of the opcode.
+**
+** Other keywords in the comment that follows each case are used to
+** construct the OPFLG_INITIALIZER value that initializes opcodeProperty[].
+** Keywords include: in1, in2, in3, out2_prerelease, out2, out3.  See
+** the mkopcodeh.awk script for additional information.
+**
+** Documentation about VDBE opcodes is generated by scanning this file
+** for lines of that contain "Opcode:".  That line and all subsequent
+** comment lines are used in the generation of the opcode.html documentation
+** file.
+**
+** SUMMARY:
+**
+**     Formatting is important to scripts that scan this file.
+**     Do not deviate from the formatting style currently in use.
+**
+*****************************************************************************/
+/* Opcode:  Goto * P2 * * *
+**
+** An unconditional jump to address P2.
+** The next instruction executed will be
+** the one at index P2 from the beginning of
+** the program.
+*/
+case OP_Goto: {             /* jump */
+CHECK_FOR_INTERRUPT;
+pc = pOp->p2 - 1;
+break;
+}
+/* Opcode:  Gosub P1 P2 * * *
+**
+** Write the current address onto register P1
+** and then jump to address P2.
+*/
+case OP_Gosub: {            /* jump */
+assert( pOp->p1>0 );
+assert( pOp->p1<=p->nMem );
+pIn1 = &p->aMem[pOp->p1];
+assert( (pIn1->flags & MEM_Dyn)==0 );
+pIn1->flags = MEM_Int;
+pIn1->u.i = pc;
+REGISTER_TRACE(pOp->p1, pIn1);
+pc = pOp->p2 - 1;
+break;
+}
+/* Opcode:  Return P1 * * * *
+**
+** Jump to the next instruction after the address in register P1.
+*/
+case OP_Return: {           /* in1 */
+assert( pIn1->flags & MEM_Int );
+pc = pIn1->u.i;
+break;
+}
+/* Opcode:  Yield P1 * * * *
+**
+** Swap the program counter with the value in register P1.
+*/
+case OP_Yield: {
+int pcDest;
+assert( pOp->p1>0 );
+assert( pOp->p1<=p->nMem );
+pIn1 = &p->aMem[pOp->p1];
+assert( (pIn1->flags & MEM_Dyn)==0 );
+pIn1->flags = MEM_Int;
+pcDest = pIn1->u.i;
+pIn1->u.i = pc;
+REGISTER_TRACE(pOp->p1, pIn1);
+pc = pcDest;
+break;
+}
+/* Opcode:  Halt P1 P2 * P4 *
+**
+** Exit immediately.  All open cursors, Fifos, etc are closed
+** automatically.
+**
+** P1 is the result code returned by sqlite3_exec(), sqlite3_reset(),
+** or sqlite3_finalize().  For a normal halt, this should be SQLITE_OK (0).
+** For errors, it can be some other value.  If P1!=0 then P2 will determine
+** whether or not to rollback the current transaction.  Do not rollback
+** if P2==OE_Fail. Do the rollback if P2==OE_Rollback.  If P2==OE_Abort,
+** then back out all changes that have occurred during this execution of the
+** VDBE, but do not rollback the transaction.
+**
+** If P4 is not null then it is an error message string.
+**
+** There is an implied "Halt 0 0 0" instruction inserted at the very end of
+** every program.  So a jump past the last instruction of the program
+** is the same as executing Halt.
+*/
+case OP_Halt: {
+p->rc = pOp->p1;
+p->pc = pc;
+p->errorAction = pOp->p2;
+if( pOp->p4.z ){
+sqlite3SetString(&p->zErrMsg, db, "%s", pOp->p4.z);
+}
+rc = sqlite3VdbeHalt(p);
+assert( rc==SQLITE_BUSY || rc==SQLITE_OK );
+if( rc==SQLITE_BUSY ){
+p->rc = rc = SQLITE_BUSY;
+}else{
+rc = p->rc ? SQLITE_ERROR : SQLITE_DONE;
+}
+goto vdbe_return;
+}
+/* Opcode: Integer P1 P2 * * *
+**
+** The 32-bit integer value P1 is written into register P2.
+*/
+case OP_Integer: {         /* out2-prerelease */
+pOut->flags = MEM_Int;
+pOut->u.i = pOp->p1;
+break;
+}
+/* Opcode: Int64 * P2 * P4 *
+**
+** P4 is a pointer to a 64-bit integer value.
+** Write that value into register P2.
+*/
+case OP_Int64: {           /* out2-prerelease */
+assert( pOp->p4.pI64!=0 );
+pOut->flags = MEM_Int;
+pOut->u.i = *pOp->p4.pI64;
+break;
+}
+/* Opcode: Real * P2 * P4 *
+**
+** P4 is a pointer to a 64-bit floating point value.
+** Write that value into register P2.
+*/
+case OP_Real: {            /* same as TK_FLOAT, out2-prerelease */
+pOut->flags = MEM_Real;
+assert( !sqlite3IsNaN(*pOp->p4.pReal) );
+pOut->r = *pOp->p4.pReal;
+break;
+}
+/* Opcode: String8 * P2 * P4 *
+**
+** P4 points to a nul terminated UTF-8 string. This opcode is transformed
+** into an OP_String before it is executed for the first time.
+*/
+case OP_String8: {         /* same as TK_STRING, out2-prerelease */
+assert( pOp->p4.z!=0 );
+pOp->opcode = OP_String;
+pOp->p1 = strlen(pOp->p4.z);
+#ifndef SQLITE_OMIT_UTF16
+if( encoding!=SQLITE_UTF8 ){
+sqlite3VdbeMemSetStr(pOut, pOp->p4.z, -1, SQLITE_UTF8, SQLITE_STATIC);
+if( SQLITE_OK!=sqlite3VdbeChangeEncoding(pOut, encoding) ) goto no_mem;
+if( SQLITE_OK!=sqlite3VdbeMemMakeWriteable(pOut) ) goto no_mem;
+pOut->zMalloc = 0;
+pOut->flags |= MEM_Static;
+pOut->flags &= ~MEM_Dyn;
+if( pOp->p4type==P4_DYNAMIC ){
+sqlite3DbFree(db, pOp->p4.z);
+}
+pOp->p4type = P4_DYNAMIC;
+pOp->p4.z = pOut->z;
+pOp->p1 = pOut->n;
+if( pOp->p1>db->aLimit[SQLITE_LIMIT_LENGTH] ){
+goto too_big;
+}
+UPDATE_MAX_BLOBSIZE(pOut);
+break;
+}
+#endif
+if( pOp->p1>db->aLimit[SQLITE_LIMIT_LENGTH] ){
+goto too_big;
+}
+/* Fall through to the next case, OP_String */
+}
+/* Opcode: String P1 P2 * P4 *
+**
+** The string value P4 of length P1 (bytes) is stored in register P2.
+*/
+case OP_String: {          /* out2-prerelease */
+assert( pOp->p4.z!=0 );
+pOut->flags = MEM_Str|MEM_Static|MEM_Term;
+pOut->z = pOp->p4.z;
+pOut->n = pOp->p1;
+pOut->enc = encoding;
+UPDATE_MAX_BLOBSIZE(pOut);
+break;
+}
+/* Opcode: Null * P2 * * *
+**
+** Write a NULL into register P2.
+*/
+case OP_Null: {           /* out2-prerelease */
+break;
+}
+#ifndef SQLITE_OMIT_BLOB_LITERAL
+/* Opcode: Blob P1 P2 * P4
+**
+** P4 points to a blob of data P1 bytes long.  Store this
+** blob in register P2. This instruction is not coded directly
+** by the compiler. Instead, the compiler layer specifies
+** an OP_HexBlob opcode, with the hex string representation of
+** the blob as P4. This opcode is transformed to an OP_Blob
+** the first time it is executed.
+*/
+case OP_Blob: {                /* out2-prerelease */
+assert( pOp->p1 <= SQLITE_MAX_LENGTH );
+sqlite3VdbeMemSetStr(pOut, pOp->p4.z, pOp->p1, 0, 0);
+pOut->enc = encoding;
+UPDATE_MAX_BLOBSIZE(pOut);
+break;
+}
+#endif /* SQLITE_OMIT_BLOB_LITERAL */
+/* Opcode: Variable P1 P2 * * *
+**
+** The value of variable P1 is written into register P2. A variable is
+** an unknown in the original SQL string as handed to sqlite3_compile().
+** Any occurrence of the '?' character in the original SQL is considered
+** a variable.  Variables in the SQL string are number from left to
+** right beginning with 1.  The values of variables are set using the
+** sqlite3_bind() API.
+*/
+case OP_Variable: {           /* out2-prerelease */
+int j = pOp->p1 - 1;
+Mem *pVar;
+assert( j>=0 && j<p->nVar );
+pVar = &p->aVar[j];
+if( sqlite3VdbeMemTooBig(pVar) ){
+goto too_big;
+}
+sqlite3VdbeMemShallowCopy(pOut, &p->aVar[j], MEM_Static);
+UPDATE_MAX_BLOBSIZE(pOut);
+break;
+}
+/* Opcode: Move P1 P2 P3 * *
+**
+** Move the values in register P1..P1+P3-1 over into
+** registers P2..P2+P3-1.  Registers P1..P1+P1-1 are
+** left holding a NULL.  It is an error for register ranges
+** P1..P1+P3-1 and P2..P2+P3-1 to overlap.
+*/
+case OP_Move: {
+char *zMalloc;
+int n = pOp->p3;
+int p1 = pOp->p1;
+int p2 = pOp->p2;
+assert( n>0 );
+assert( p1>0 );
+assert( p1+n<p->nMem );
+pIn1 = &p->aMem[p1];
+assert( p2>0 );
+assert( p2+n<p->nMem );
+pOut = &p->aMem[p2];
+assert( p1+n<=p2 || p2+n<=p1 );
+while( n-- ){
+zMalloc = pOut->zMalloc;
+pOut->zMalloc = 0;
+sqlite3VdbeMemMove(pOut, pIn1);
+pIn1->zMalloc = zMalloc;
+REGISTER_TRACE(p2++, pOut);
+pIn1++;
+pOut++;
+}
+break;
+}
+/* Opcode: Copy P1 P2 * * *
+**
+** Make a copy of register P1 into register P2.
+**
+** This instruction makes a deep copy of the value.  A duplicate
+** is made of any string or blob constant.  See also OP_SCopy.
+*/
+case OP_Copy: {
+assert( pOp->p1>0 );
+assert( pOp->p1<=p->nMem );
+pIn1 = &p->aMem[pOp->p1];
+assert( pOp->p2>0 );
+assert( pOp->p2<=p->nMem );
+pOut = &p->aMem[pOp->p2];
+assert( pOut!=pIn1 );
+sqlite3VdbeMemShallowCopy(pOut, pIn1, MEM_Ephem);
+Deephemeralize(pOut);
+REGISTER_TRACE(pOp->p2, pOut);
+break;
+}
+/* Opcode: SCopy P1 P2 * * *
+**
+** Make a shallow copy of register P1 into register P2.
+**
+** This instruction makes a shallow copy of the value.  If the value
+** is a string or blob, then the copy is only a pointer to the
+** original and hence if the original changes so will the copy.
+** Worse, if the original is deallocated, the copy becomes invalid.
+** Thus the program must guarantee that the original will not change
+** during the lifetime of the copy.  Use OP_Copy to make a complete
+** copy.
+*/
+case OP_SCopy: {
+assert( pOp->p1>0 );
+assert( pOp->p1<=p->nMem );
+pIn1 = &p->aMem[pOp->p1];
+REGISTER_TRACE(pOp->p1, pIn1);
+assert( pOp->p2>0 );
+assert( pOp->p2<=p->nMem );
+pOut = &p->aMem[pOp->p2];
+assert( pOut!=pIn1 );
+sqlite3VdbeMemShallowCopy(pOut, pIn1, MEM_Ephem);
+REGISTER_TRACE(pOp->p2, pOut);
+break;
+}
+/* Opcode: ResultRow P1 P2 * * *
+**
+** The registers P1 through P1+P2-1 contain a single row of
+** results. This opcode causes the sqlite3_step() call to terminate
+** with an SQLITE_ROW return code and it sets up the sqlite3_stmt
+** structure to provide access to the top P1 values as the result
+** row.
+*/
+case OP_ResultRow: {
+Mem *pMem;
+int i;
+assert( p->nResColumn==pOp->p2 );
+assert( pOp->p1>0 );
+assert( pOp->p1+pOp->p2<=p->nMem );
+/* Invalidate all ephemeral cursor row caches */
+p->cacheCtr = (p->cacheCtr + 2)|1;
+/* Make sure the results of the current row are \000 terminated
+** and have an assigned type.  The results are de-ephemeralized as
+** as side effect.
+*/
+pMem = p->pResultSet = &p->aMem[pOp->p1];
+for(i=0; i<pOp->p2; i++){
+sqlite3VdbeMemNulTerminate(&pMem[i]);
+storeTypeInfo(&pMem[i], encoding);
+REGISTER_TRACE(pOp->p1+i, &pMem[i]);
+}
+if( db->mallocFailed ) goto no_mem;
+/* Return SQLITE_ROW
+*/
+p->nCallback++;
+p->pc = pc + 1;
+rc = SQLITE_ROW;
+goto vdbe_return;
+}
+/* Opcode: Concat P1 P2 P3 * *
+**
+** Add the text in register P1 onto the end of the text in
+** register P2 and store the result in register P3.
+** If either the P1 or P2 text are NULL then store NULL in P3.
+**
+**   P3 = P2 || P1
+**
+** It is illegal for P1 and P3 to be the same register. Sometimes,
+** if P3 is the same register as P2, the implementation is able
+** to avoid a memcpy().
+*/
+case OP_Concat: {           /* same as TK_CONCAT, in1, in2, out3 */
+i64 nByte;
+assert( pIn1!=pOut );
+if( (pIn1->flags | pIn2->flags) & MEM_Null ){
+sqlite3VdbeMemSetNull(pOut);
+break;
+}
+ExpandBlob(pIn1);
+Stringify(pIn1, encoding);
+ExpandBlob(pIn2);
+Stringify(pIn2, encoding);
+nByte = pIn1->n + pIn2->n;
+if( nByte>db->aLimit[SQLITE_LIMIT_LENGTH] ){
+goto too_big;
+}
+MemSetTypeFlag(pOut, MEM_Str);
+if( sqlite3VdbeMemGrow(pOut, nByte+2, pOut==pIn2) ){
+goto no_mem;
+}
+if( pOut!=pIn2 ){
+memcpy(pOut->z, pIn2->z, pIn2->n);
+}
+memcpy(&pOut->z[pIn2->n], pIn1->z, pIn1->n);
+pOut->z[nByte] = 0;
+pOut->z[nByte+1] = 0;
+pOut->flags |= MEM_Term;
+pOut->n = nByte;
+pOut->enc = encoding;
+UPDATE_MAX_BLOBSIZE(pOut);
+break;
+}
+/* Opcode: Add P1 P2 P3 * *
+**
+** Add the value in register P1 to the value in register P2
+** and store the result in register P3.
+** If either input is NULL, the result is NULL.
+*/
+/* Opcode: Multiply P1 P2 P3 * *
+**
+**
+** Multiply the value in register P1 by the value in register P2
+** and store the result in register P3.
+** If either input is NULL, the result is NULL.
+*/
+/* Opcode: Subtract P1 P2 P3 * *
+**
+** Subtract the value in register P1 from the value in register P2
+** and store the result in register P3.
+** If either input is NULL, the result is NULL.
+*/
+/* Opcode: Divide P1 P2 P3 * *
+**
+** Divide the value in register P1 by the value in register P2
+** and store the result in register P3.  If the value in register P2
+** is zero, then the result is NULL.
+** If either input is NULL, the result is NULL.
+*/
+/* Opcode: Remainder P1 P2 P3 * *
+**
+** Compute the remainder after integer division of the value in
+** register P1 by the value in register P2 and store the result in P3.
+** If the value in register P2 is zero the result is NULL.
+** If either operand is NULL, the result is NULL.
+*/
+case OP_Add:                   /* same as TK_PLUS, in1, in2, out3 */
+case OP_Subtract:              /* same as TK_MINUS, in1, in2, out3 */
+case OP_Multiply:              /* same as TK_STAR, in1, in2, out3 */
+case OP_Divide:                /* same as TK_SLASH, in1, in2, out3 */
+case OP_Remainder: {           /* same as TK_REM, in1, in2, out3 */
+int flags;
+applyNumericAffinity(pIn1);
+applyNumericAffinity(pIn2);
+flags = pIn1->flags | pIn2->flags;
+if( (flags & MEM_Null)!=0 ) goto arithmetic_result_is_null;
+if( (pIn1->flags & pIn2->flags & MEM_Int)==MEM_Int ){
+i64 a, b;
+a = pIn1->u.i;
+b = pIn2->u.i;
+switch( pOp->opcode ){
+case OP_Add:         b += a;       break;
+case OP_Subtract:    b -= a;       break;
+case OP_Multiply:    b *= a;       break;
+case OP_Divide: {
+if( a==0 ) goto arithmetic_result_is_null;
+/* Dividing the largest possible negative 64-bit integer (1<<63) by
+** -1 returns an integer too large to store in a 64-bit data-type. On
+** some architectures, the value overflows to (1<<63). On others,
+** a SIGFPE is issued. The following statement normalizes this
+** behavior so that all architectures behave as if integer
+** overflow occurred.
+*/
+if( a==-1 && b==SMALLEST_INT64 ) a = 1;
+b /= a;
+break;
+}
+default: {
+if( a==0 ) goto arithmetic_result_is_null;
+if( a==-1 ) a = 1;
+b %= a;
+break;
+}
+}
+pOut->u.i = b;
+MemSetTypeFlag(pOut, MEM_Int);
+}else{
+double a, b;
+a = sqlite3VdbeRealValue(pIn1);
+b = sqlite3VdbeRealValue(pIn2);
+switch( pOp->opcode ){
+case OP_Add:         b += a;       break;
+case OP_Subtract:    b -= a;       break;
+case OP_Multiply:    b *= a;       break;
+case OP_Divide: {
+if( a==0.0 ) goto arithmetic_result_is_null;
+b /= a;
+break;
+}
+default: {
+i64 ia = (i64)a;
+i64 ib = (i64)b;
+if( ia==0 ) goto arithmetic_result_is_null;
+if( ia==-1 ) ia = 1;
+b = ib % ia;
+break;
+}
+}
+if( sqlite3IsNaN(b) ){
+goto arithmetic_result_is_null;
+}
+pOut->r = b;
+MemSetTypeFlag(pOut, MEM_Real);
+if( (flags & MEM_Real)==0 ){
+sqlite3VdbeIntegerAffinity(pOut);
+}
+}
+break;
+arithmetic_result_is_null:
+sqlite3VdbeMemSetNull(pOut);
+break;
+}
+/* Opcode: CollSeq * * P4
+**
+** P4 is a pointer to a CollSeq struct. If the next call to a user function
+** or aggregate calls sqlite3GetFuncCollSeq(), this collation sequence will
+** be returned. This is used by the built-in min(), max() and nullif()
+** functions.
+**
+** The interface used by the implementation of the aforementioned functions
+** to retrieve the collation sequence set by this opcode is not available
+** publicly, only to user functions defined in func.c.
+*/
+case OP_CollSeq: {
+assert( pOp->p4type==P4_COLLSEQ );
+break;
+}
+/* Opcode: Function P1 P2 P3 P4 P5
+**
+** Invoke a user function (P4 is a pointer to a Function structure that
+** defines the function) with P5 arguments taken from register P2 and
+** successors.  The result of the function is stored in register P3.
+** Register P3 must not be one of the function inputs.
+**
+** P1 is a 32-bit bitmask indicating whether or not each argument to the
+** function was determined to be constant at compile time. If the first
+** argument was constant then bit 0 of P1 is set. This is used to determine
+** whether meta data associated with a user function argument using the
+** sqlite3_set_auxdata() API may be safely retained until the next
+** invocation of this opcode.
+**
+** See also: AggStep and AggFinal
+*/
+case OP_Function: {
+int i;
+Mem *pArg;
+sqlite3_context ctx;
+sqlite3_value **apVal;
+int n = pOp->p5;
+apVal = p->apArg;
+assert( apVal || n==0 );
+assert( n==0 || (pOp->p2>0 && pOp->p2+n<=p->nMem) );
+assert( pOp->p3<pOp->p2 || pOp->p3>=pOp->p2+n );
+pArg = &p->aMem[pOp->p2];
+for(i=0; i<n; i++, pArg++){
+apVal[i] = pArg;
+storeTypeInfo(pArg, encoding);
+REGISTER_TRACE(pOp->p2, pArg);
+}
+assert( pOp->p4type==P4_FUNCDEF || pOp->p4type==P4_VDBEFUNC );
+if( pOp->p4type==P4_FUNCDEF ){
+ctx.pFunc = pOp->p4.pFunc;
+ctx.pVdbeFunc = 0;
+}else{
+ctx.pVdbeFunc = (VdbeFunc*)pOp->p4.pVdbeFunc;
+ctx.pFunc = ctx.pVdbeFunc->pFunc;
+}
+assert( pOp->p3>0 && pOp->p3<=p->nMem );
+pOut = &p->aMem[pOp->p3];
+ctx.s.flags = MEM_Null;
+ctx.s.db = db;
+ctx.s.xDel = 0;
+ctx.s.zMalloc = 0;
+/* The output cell may already have a buffer allocated. Move
+** the pointer to ctx.s so in case the user-function can use
+** the already allocated buffer instead of allocating a new one.
+*/
+sqlite3VdbeMemMove(&ctx.s, pOut);
+MemSetTypeFlag(&ctx.s, MEM_Null);
+ctx.isError = 0;
+if( ctx.pFunc->needCollSeq ){
+assert( pOp>p->aOp );
+assert( pOp[-1].p4type==P4_COLLSEQ );
+assert( pOp[-1].opcode==OP_CollSeq );
+ctx.pColl = pOp[-1].p4.pColl;
+}
+if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
+(*ctx.pFunc->xFunc)(&ctx, n, apVal);
+if( sqlite3SafetyOn(db) ){
+sqlite3VdbeMemRelease(&ctx.s);
+goto abort_due_to_misuse;
+}
+if( db->mallocFailed ){
+/* Even though a malloc() has failed, the implementation of the
+** user function may have called an sqlite3_result_XXX() function
+** to return a value. The following call releases any resources
+** associated with such a value.
+**
+** Note: Maybe MemRelease() should be called if sqlite3SafetyOn()
+** fails also (the if(...) statement above). But if people are
+** misusing sqlite, they have bigger problems than a leaked value.
+*/
+sqlite3VdbeMemRelease(&ctx.s);
+goto no_mem;
+}
+/* If any auxiliary data functions have been called by this user function,
+** immediately call the destructor for any non-static values.
+*/
+if( ctx.pVdbeFunc ){
+sqlite3VdbeDeleteAuxData(ctx.pVdbeFunc, pOp->p1);
+pOp->p4.pVdbeFunc = ctx.pVdbeFunc;
+pOp->p4type = P4_VDBEFUNC;
+}
+/* If the function returned an error, throw an exception */
+if( ctx.isError ){
+sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3_value_text(&ctx.s));
+rc = ctx.isError;
+}
+/* Copy the result of the function into register P3 */
+sqlite3VdbeChangeEncoding(&ctx.s, encoding);
+sqlite3VdbeMemMove(pOut, &ctx.s);
+if( sqlite3VdbeMemTooBig(pOut) ){
+goto too_big;
+}
+REGISTER_TRACE(pOp->p3, pOut);
+UPDATE_MAX_BLOBSIZE(pOut);
+break;
+}
+/* Opcode: BitAnd P1 P2 P3 * *
+**
+** Take the bit-wise AND of the values in register P1 and P2 and
+** store the result in register P3.
+** If either input is NULL, the result is NULL.
+*/
+/* Opcode: BitOr P1 P2 P3 * *
+**
+** Take the bit-wise OR of the values in register P1 and P2 and
+** store the result in register P3.
+** If either input is NULL, the result is NULL.
+*/
+/* Opcode: ShiftLeft P1 P2 P3 * *
+**
+** Shift the integer value in register P2 to the left by the
+** number of bits specified by the integer in regiser P1.
+** Store the result in register P3.
+** If either input is NULL, the result is NULL.
+*/
+/* Opcode: ShiftRight P1 P2 P3 * *
+**
+** Shift the integer value in register P2 to the right by the
+** number of bits specified by the integer in register P1.
+** Store the result in register P3.
+** If either input is NULL, the result is NULL.
+*/
+case OP_BitAnd:                 /* same as TK_BITAND, in1, in2, out3 */
+case OP_BitOr:                  /* same as TK_BITOR, in1, in2, out3 */
+case OP_ShiftLeft:              /* same as TK_LSHIFT, in1, in2, out3 */
+case OP_ShiftRight: {           /* same as TK_RSHIFT, in1, in2, out3 */
+i64 a, b;
+if( (pIn1->flags | pIn2->flags) & MEM_Null ){
+sqlite3VdbeMemSetNull(pOut);
+break;
+}
+a = sqlite3VdbeIntValue(pIn2);
+b = sqlite3VdbeIntValue(pIn1);
+switch( pOp->opcode ){
+case OP_BitAnd:      a &= b;     break;
+case OP_BitOr:       a |= b;     break;
+case OP_ShiftLeft:   a <<= b;    break;
+default:  assert( pOp->opcode==OP_ShiftRight );
+a >>= b;    break;
+}
+pOut->u.i = a;
+MemSetTypeFlag(pOut, MEM_Int);
+break;
+}
+/* Opcode: AddImm  P1 P2 * * *
+**
+** Add the constant P2 to the value in register P1.
+** The result is always an integer.
+**
+** To force any register to be an integer, just add 0.
+*/
+case OP_AddImm: {            /* in1 */
+sqlite3VdbeMemIntegerify(pIn1);
+pIn1->u.i += pOp->p2;
+break;
+}
+/* Opcode: ForceInt P1 P2 P3 * *
+**
+** Convert value in register P1 into an integer.  If the value
+** in P1 is not numeric (meaning that is is a NULL or a string that
+** does not look like an integer or floating point number) then
+** jump to P2.  If the value in P1 is numeric then
+** convert it into the least integer that is greater than or equal to its
+** current value if P3==0, or to the least integer that is strictly
+** greater than its current value if P3==1.
+*/
+case OP_ForceInt: {            /* jump, in1 */
+i64 v;
+applyAffinity(pIn1, SQLITE_AFF_NUMERIC, encoding);
+if( (pIn1->flags & (MEM_Int|MEM_Real))==0 ){
+pc = pOp->p2 - 1;
+break;
+}
+if( pIn1->flags & MEM_Int ){
+v = pIn1->u.i + (pOp->p3!=0);
+}else{
+assert( pIn1->flags & MEM_Real );
+v = (sqlite3_int64)pIn1->r;
+if( pIn1->r>(double)v ) v++;
+if( pOp->p3 && pIn1->r==(double)v ) v++;
+}
+pIn1->u.i = v;
+MemSetTypeFlag(pIn1, MEM_Int);
+break;
+}
+/* Opcode: MustBeInt P1 P2 * * *
+**
+** Force the value in register P1 to be an integer.  If the value
+** in P1 is not an integer and cannot be converted into an integer
+** without data loss, then jump immediately to P2, or if P2==0
+** raise an SQLITE_MISMATCH exception.
+*/
+case OP_MustBeInt: {            /* jump, in1 */
+applyAffinity(pIn1, SQLITE_AFF_NUMERIC, encoding);
+if( (pIn1->flags & MEM_Int)==0 ){
+if( pOp->p2==0 ){
+rc = SQLITE_MISMATCH;
+goto abort_due_to_error;
+}else{
+pc = pOp->p2 - 1;
+}
+}else{
+MemSetTypeFlag(pIn1, MEM_Int);
+}
+break;
+}
+/* Opcode: RealAffinity P1 * * * *
+**
+** If register P1 holds an integer convert it to a real value.
+**
+** This opcode is used when extracting information from a column that
+** has REAL affinity.  Such column values may still be stored as
+** integers, for space efficiency, but after extraction we want them
+** to have only a real value.
+*/
+case OP_RealAffinity: {                  /* in1 */
+if( pIn1->flags & MEM_Int ){
+sqlite3VdbeMemRealify(pIn1);
+}
+break;
+}
+#ifndef SQLITE_OMIT_CAST
+/* Opcode: ToText P1 * * * *
+**
+** Force the value in register P1 to be text.
+** If the value is numeric, convert it to a string using the
+** equivalent of printf().  Blob values are unchanged and
+** are afterwards simply interpreted as text.
+**
+** A NULL value is not changed by this routine.  It remains NULL.
+*/
+case OP_ToText: {                  /* same as TK_TO_TEXT, in1 */
+if( pIn1->flags & MEM_Null ) break;
+assert( MEM_Str==(MEM_Blob>>3) );
+pIn1->flags |= (pIn1->flags&MEM_Blob)>>3;
+applyAffinity(pIn1, SQLITE_AFF_TEXT, encoding);
+rc = ExpandBlob(pIn1);
+assert( pIn1->flags & MEM_Str || db->mallocFailed );
+pIn1->flags &= ~(MEM_Int|MEM_Real|MEM_Blob);
+UPDATE_MAX_BLOBSIZE(pIn1);
+break;
+}
+/* Opcode: ToBlob P1 * * * *
+**
+** Force the value in register P1 to be a BLOB.
+** If the value is numeric, convert it to a string first.
+** Strings are simply reinterpreted as blobs with no change
+** to the underlying data.
+**
+** A NULL value is not changed by this routine.  It remains NULL.
+*/
+case OP_ToBlob: {                  /* same as TK_TO_BLOB, in1 */
+if( pIn1->flags & MEM_Null ) break;
+if( (pIn1->flags & MEM_Blob)==0 ){
+applyAffinity(pIn1, SQLITE_AFF_TEXT, encoding);
+assert( pIn1->flags & MEM_Str || db->mallocFailed );
+}
+MemSetTypeFlag(pIn1, MEM_Blob);
+UPDATE_MAX_BLOBSIZE(pIn1);
+break;
+}
+/* Opcode: ToNumeric P1 * * * *
+**
+** Force the value in register P1 to be numeric (either an
+** integer or a floating-point number.)
+** If the value is text or blob, try to convert it to an using the
+** equivalent of atoi() or atof() and store 0 if no such conversion
+** is possible.
+**
+** A NULL value is not changed by this routine.  It remains NULL.
+*/
+case OP_ToNumeric: {                  /* same as TK_TO_NUMERIC, in1 */
+if( (pIn1->flags & (MEM_Null|MEM_Int|MEM_Real))==0 ){
+sqlite3VdbeMemNumerify(pIn1);
+}
+break;
+}
+#endif /* SQLITE_OMIT_CAST */
+/* Opcode: ToInt P1 * * * *
+**
+** Force the value in register P1 be an integer.  If
+** The value is currently a real number, drop its fractional part.
+** If the value is text or blob, try to convert it to an integer using the
+** equivalent of atoi() and store 0 if no such conversion is possible.
+**
+** A NULL value is not changed by this routine.  It remains NULL.
+*/
+case OP_ToInt: {                  /* same as TK_TO_INT, in1 */
+if( (pIn1->flags & MEM_Null)==0 ){
+sqlite3VdbeMemIntegerify(pIn1);
+}
+break;
+}
+#ifndef SQLITE_OMIT_CAST
+/* Opcode: ToReal P1 * * * *
+**
+** Force the value in register P1 to be a floating point number.
+** If The value is currently an integer, convert it.
+** If the value is text or blob, try to convert it to an integer using the
+** equivalent of atoi() and store 0.0 if no such conversion is possible.
+**
+** A NULL value is not changed by this routine.  It remains NULL.
+*/
+case OP_ToReal: {                  /* same as TK_TO_REAL, in1 */
+if( (pIn1->flags & MEM_Null)==0 ){
+sqlite3VdbeMemRealify(pIn1);
+}
+break;
+}
+#endif /* SQLITE_OMIT_CAST */
+/* Opcode: Lt P1 P2 P3 P4 P5
+**
+** Compare the values in register P1 and P3.  If reg(P3)<reg(P1) then
+** jump to address P2.
+**
+** If the SQLITE_JUMPIFNULL bit of P5 is set and either reg(P1) or
+** reg(P3) is NULL then take the jump.  If the SQLITE_JUMPIFNULL
+** bit is clear then fall thru if either operand is NULL.
+**
+** The SQLITE_AFF_MASK portion of P5 must be an affinity character -
+** SQLITE_AFF_TEXT, SQLITE_AFF_INTEGER, and so forth. An attempt is made
+** to coerce both inputs according to this affinity before the
+** comparison is made. If the SQLITE_AFF_MASK is 0x00, then numeric
+** affinity is used. Note that the affinity conversions are stored
+** back into the input registers P1 and P3.  So this opcode can cause
+** persistent changes to registers P1 and P3.
+**
+** Once any conversions have taken place, and neither value is NULL,
+** the values are compared. If both values are blobs then memcmp() is
+** used to determine the results of the comparison.  If both values
+** are text, then the appropriate collating function specified in
+** P4 is  used to do the comparison.  If P4 is not specified then
+** memcmp() is used to compare text string.  If both values are
+** numeric, then a numeric comparison is used. If the two values
+** are of different types, then numbers are considered less than
+** strings and strings are considered less than blobs.
+**
+** If the SQLITE_STOREP2 bit of P5 is set, then do not jump.  Instead,
+** store a boolean result (either 0, or 1, or NULL) in register P2.
+*/
+/* Opcode: Ne P1 P2 P3 P4 P5
+**
+** This works just like the Lt opcode except that the jump is taken if
+** the operands in registers P1 and P3 are not equal.  See the Lt opcode for
+** additional information.
+*/
+/* Opcode: Eq P1 P2 P3 P4 P5
+**
+** This works just like the Lt opcode except that the jump is taken if
+** the operands in registers P1 and P3 are equal.
+** See the Lt opcode for additional information.
+*/
+/* Opcode: Le P1 P2 P3 P4 P5
+**
+** This works just like the Lt opcode except that the jump is taken if
+** the content of register P3 is less than or equal to the content of
+** register P1.  See the Lt opcode for additional information.
+*/
+/* Opcode: Gt P1 P2 P3 P4 P5
+**
+** This works just like the Lt opcode except that the jump is taken if
+** the content of register P3 is greater than the content of
+** register P1.  See the Lt opcode for additional information.
+*/
+/* Opcode: Ge P1 P2 P3 P4 P5
+**
+** This works just like the Lt opcode except that the jump is taken if
+** the content of register P3 is greater than or equal to the content of
+** register P1.  See the Lt opcode for additional information.
+*/
+case OP_Eq:               /* same as TK_EQ, jump, in1, in3 */
+case OP_Ne:               /* same as TK_NE, jump, in1, in3 */
+case OP_Lt:               /* same as TK_LT, jump, in1, in3 */
+case OP_Le:               /* same as TK_LE, jump, in1, in3 */
+case OP_Gt:               /* same as TK_GT, jump, in1, in3 */
+case OP_Ge: {             /* same as TK_GE, jump, in1, in3 */
+int flags;
+int res;
+char affinity;
+flags = pIn1->flags|pIn3->flags;
+if( flags&MEM_Null ){
+/* If either operand is NULL then the result is always NULL.
+** The jump is taken if the SQLITE_JUMPIFNULL bit is set.
+*/
+if( pOp->p5 & SQLITE_STOREP2 ){
+pOut = &p->aMem[pOp->p2];
+MemSetTypeFlag(pOut, MEM_Null);
+REGISTER_TRACE(pOp->p2, pOut);
+}else if( pOp->p5 & SQLITE_JUMPIFNULL ){
+pc = pOp->p2-1;
+}
+break;
+}
+affinity = pOp->p5 & SQLITE_AFF_MASK;
+if( affinity ){
+applyAffinity(pIn1, affinity, encoding);
+applyAffinity(pIn3, affinity, encoding);
+}
+assert( pOp->p4type==P4_COLLSEQ || pOp->p4.pColl==0 );
+ExpandBlob(pIn1);
+ExpandBlob(pIn3);
+res = sqlite3MemCompare(pIn3, pIn1, pOp->p4.pColl);
+switch( pOp->opcode ){
+case OP_Eq:    res = res==0;     break;
+case OP_Ne:    res = res!=0;     break;
+case OP_Lt:    res = res<0;      break;
+case OP_Le:    res = res<=0;     break;
+case OP_Gt:    res = res>0;      break;
+default:       res = res>=0;     break;
+}
+if( pOp->p5 & SQLITE_STOREP2 ){
+pOut = &p->aMem[pOp->p2];
+MemSetTypeFlag(pOut, MEM_Int);
+pOut->u.i = res;
+REGISTER_TRACE(pOp->p2, pOut);
+}else if( res ){
+pc = pOp->p2-1;
+}
+break;
+}
+/* Opcode: Permutation * * * P4 *
+**
+** Set the permuation used by the OP_Compare operator to be the array
+** of integers in P4.
+**
+** The permutation is only valid until the next OP_Permutation, OP_Compare,
+** OP_Halt, or OP_ResultRow.  Typically the OP_Permutation should occur
+** immediately prior to the OP_Compare.
+*/
+case OP_Permutation: {
+assert( pOp->p4type==P4_INTARRAY );
+assert( pOp->p4.ai );
+aPermute = pOp->p4.ai;
+break;
+}
+/* Opcode: Compare P1 P2 P3 P4 *
+**
+** Compare to vectors of registers in reg(P1)..reg(P1+P3-1) (all this
+** one "A") and in reg(P2)..reg(P2+P3-1) ("B").  Save the result of
+** the comparison for use by the next OP_Jump instruct.
+**
+** P4 is a KeyInfo structure that defines collating sequences and sort
+** orders for the comparison.  The permutation applies to registers
+** only.  The KeyInfo elements are used sequentially.
+**
+** The comparison is a sort comparison, so NULLs compare equal,
+** NULLs are less than numbers, numbers are less than strings,
+** and strings are less than blobs.
+*/
+case OP_Compare: {
+int n = pOp->p3;
+int i, p1, p2;
+const KeyInfo *pKeyInfo = pOp->p4.pKeyInfo;
+assert( n>0 );
+assert( pKeyInfo!=0 );
+p1 = pOp->p1;
+assert( p1>0 && p1+n-1<p->nMem );
+p2 = pOp->p2;
+assert( p2>0 && p2+n-1<p->nMem );
+for(i=0; i<n; i++){
+int idx = aPermute ? aPermute[i] : i;
+CollSeq *pColl;    /* Collating sequence to use on this term */
+int bRev;          /* True for DESCENDING sort order */
+REGISTER_TRACE(p1+idx, &p->aMem[p1+idx]);
+REGISTER_TRACE(p2+idx, &p->aMem[p2+idx]);
+assert( i<pKeyInfo->nField );
+pColl = pKeyInfo->aColl[i];
+bRev = pKeyInfo->aSortOrder[i];
+iCompare = sqlite3MemCompare(&p->aMem[p1+idx], &p->aMem[p2+idx], pColl);
+if( iCompare ){
+if( bRev ) iCompare = -iCompare;
+break;
+}
+}
+aPermute = 0;
+break;
+}
+/* Opcode: Jump P1 P2 P3 * *
+**
+** Jump to the instruction at address P1, P2, or P3 depending on whether
+** in the most recent OP_Compare instruction the P1 vector was less than
+** equal to, or greater than the P2 vector, respectively.
+*/
+case OP_Jump: {             /* jump */
+if( iCompare<0 ){
+pc = pOp->p1 - 1;
+}else if( iCompare==0 ){
+pc = pOp->p2 - 1;
+}else{
+pc = pOp->p3 - 1;
+}
+break;
+}
+/* Opcode: And P1 P2 P3 * *
+**
+** Take the logical AND of the values in registers P1 and P2 and
+** write the result into register P3.
+**
+** If either P1 or P2 is 0 (false) then the result is 0 even if
+** the other input is NULL.  A NULL and true or two NULLs give
+** a NULL output.
+*/
+/* Opcode: Or P1 P2 P3 * *
+**
+** Take the logical OR of the values in register P1 and P2 and
+** store the answer in register P3.
+**
+** If either P1 or P2 is nonzero (true) then the result is 1 (true)
+** even if the other input is NULL.  A NULL and false or two NULLs
+** give a NULL output.
+*/
+case OP_And:              /* same as TK_AND, in1, in2, out3 */
+case OP_Or: {             /* same as TK_OR, in1, in2, out3 */
+int v1, v2;    /* 0==FALSE, 1==TRUE, 2==UNKNOWN or NULL */
+if( pIn1->flags & MEM_Null ){
+v1 = 2;
+}else{
+v1 = sqlite3VdbeIntValue(pIn1)!=0;
+}
+if( pIn2->flags & MEM_Null ){
+v2 = 2;
+}else{
+v2 = sqlite3VdbeIntValue(pIn2)!=0;
+}
+if( pOp->opcode==OP_And ){
+static const unsigned char and_logic[] = { 0, 0, 0, 0, 1, 2, 0, 2, 2 };
+v1 = and_logic[v1*3+v2];
+}else{
+static const unsigned char or_logic[] = { 0, 1, 2, 1, 1, 1, 2, 1, 2 };
+v1 = or_logic[v1*3+v2];
+}
+if( v1==2 ){
+MemSetTypeFlag(pOut, MEM_Null);
+}else{
+pOut->u.i = v1;
+MemSetTypeFlag(pOut, MEM_Int);
+}
+break;
+}
+/* Opcode: Not P1 * * * *
+**
+** Interpret the value in register P1 as a boolean value.  Replace it
+** with its complement.  If the value in register P1 is NULL its value
+** is unchanged.
+*/
+case OP_Not: {                /* same as TK_NOT, in1 */
+if( pIn1->flags & MEM_Null ) break;  /* Do nothing to NULLs */
+sqlite3VdbeMemIntegerify(pIn1);
+pIn1->u.i = !pIn1->u.i;
+assert( pIn1->flags&MEM_Int );
+break;
+}
+/* Opcode: BitNot P1 * * * *
+**
+** Interpret the content of register P1 as an integer.  Replace it
+** with its ones-complement.  If the value is originally NULL, leave
+** it unchanged.
+*/
+case OP_BitNot: {             /* same as TK_BITNOT, in1 */
+if( pIn1->flags & MEM_Null ) break;  /* Do nothing to NULLs */
+sqlite3VdbeMemIntegerify(pIn1);
+pIn1->u.i = ~pIn1->u.i;
+assert( pIn1->flags&MEM_Int );
+break;
+}
+/* Opcode: If P1 P2 P3 * *
+**
+** Jump to P2 if the value in register P1 is true.  The value is
+** is considered true if it is numeric and non-zero.  If the value
+** in P1 is NULL then take the jump if P3 is true.
+*/
+/* Opcode: IfNot P1 P2 P3 * *
+**
+** Jump to P2 if the value in register P1 is False.  The value is
+** is considered true if it has a numeric value of zero.  If the value
+** in P1 is NULL then take the jump if P3 is true.
+*/
+case OP_If:                 /* jump, in1 */
+case OP_IfNot: {            /* jump, in1 */
+int c;
+if( pIn1->flags & MEM_Null ){
+c = pOp->p3;
+}else{
+#ifdef SQLITE_OMIT_FLOATING_POINT
+c = sqlite3VdbeIntValue(pIn1);
+#else
+c = sqlite3VdbeRealValue(pIn1)!=0.0;
+#endif
+if( pOp->opcode==OP_IfNot ) c = !c;
+}
+if( c ){
+pc = pOp->p2-1;
+}
+break;
+}
+/* Opcode: IsNull P1 P2 P3 * *
+**
+** Jump to P2 if the value in register P1 is NULL.  If P3 is greater
+** than zero, then check all values reg(P1), reg(P1+1),
+** reg(P1+2), ..., reg(P1+P3-1).
+*/
+case OP_IsNull: {            /* same as TK_ISNULL, jump, in1 */
+int n = pOp->p3;
+assert( pOp->p3==0 || pOp->p1>0 );
+do{
+if( (pIn1->flags & MEM_Null)!=0 ){
+pc = pOp->p2 - 1;
+break;
+}
+pIn1++;
+}while( --n > 0 );
+break;
+}
+/* Opcode: NotNull P1 P2 * * *
+**
+** Jump to P2 if the value in register P1 is not NULL.
+*/
+case OP_NotNull: {            /* same as TK_NOTNULL, jump, in1 */
+if( (pIn1->flags & MEM_Null)==0 ){
+pc = pOp->p2 - 1;
+}
+break;
+}
+/* Opcode: SetNumColumns * P2 * * *
+**
+** This opcode sets the number of columns for the cursor opened by the
+** following instruction to P2.
+**
+** An OP_SetNumColumns is only useful if it occurs immediately before
+** one of the following opcodes:
+**
+**     OpenRead
+**     OpenWrite
+**     OpenPseudo
+**
+** If the OP_Column opcode is to be executed on a cursor, then
+** this opcode must be present immediately before the opcode that
+** opens the cursor.
+*/
+case OP_SetNumColumns: {
+break;
+}
+/* Opcode: Column P1 P2 P3 P4 *
+**
+** Interpret the data that cursor P1 points to as a structure built using
+** the MakeRecord instruction.  (See the MakeRecord opcode for additional
+** information about the format of the data.)  Extract the P2-th column
+** from this record.  If there are less that (P2+1)
+** values in the record, extract a NULL.
+**
+** The value extracted is stored in register P3.
+**
+** If the KeyAsData opcode has previously executed on this cursor, then the
+** field might be extracted from the key rather than the data.
+**
+** If the column contains fewer than P2 fields, then extract a NULL.  Or,
+** if the P4 argument is a P4_MEM use the value of the P4 argument as
+** the result.
+*/
+case OP_Column: {
+u32 payloadSize;   /* Number of bytes in the record */
+int p1 = pOp->p1;  /* P1 value of the opcode */
+int p2 = pOp->p2;  /* column number to retrieve */
+Cursor *pC = 0;    /* The VDBE cursor */
+char *zRec;        /* Pointer to complete record-data */
+BtCursor *pCrsr;   /* The BTree cursor */
+u32 *aType;        /* aType[i] holds the numeric type of the i-th column */
+u32 *aOffset;      /* aOffset[i] is offset to start of data for i-th column */
+u32 nField;        /* number of fields in the record */
+int len;           /* The length of the serialized data for the column */
+int i;             /* Loop counter */
+char *zData;       /* Part of the record being decoded */
+Mem *pDest;        /* Where to write the extracted value */
+Mem sMem;          /* For storing the record being decoded */
+sMem.flags = 0;
+sMem.db = 0;
+sMem.zMalloc = 0;
+assert( p1<p->nCursor );
+assert( pOp->p3>0 && pOp->p3<=p->nMem );
+pDest = &p->aMem[pOp->p3];
+MemSetTypeFlag(pDest, MEM_Null);
+/* This block sets the variable payloadSize to be the total number of
+** bytes in the record.
+**
+** zRec is set to be the complete text of the record if it is available.
+** The complete record text is always available for pseudo-tables
+** If the record is stored in a cursor, the complete record text
+** might be available in the  pC->aRow cache.  Or it might not be.
+** If the data is unavailable,  zRec is set to NULL.
+**
+** We also compute the number of columns in the record.  For cursors,
+** the number of columns is stored in the Cursor.nField element.
+*/
+pC = p->apCsr[p1];
+assert( pC!=0 );
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+assert( pC->pVtabCursor==0 );
+#endif
+if( pC->pCursor!=0 ){
+/* The record is stored in a B-Tree */
+rc = sqlite3VdbeCursorMoveto(pC);
+if( rc ) goto abort_due_to_error;
+zRec = 0;
+pCrsr = pC->pCursor;
+if( pC->nullRow ){
+payloadSize = 0;
+}else if( pC->cacheStatus==p->cacheCtr ){
+payloadSize = pC->payloadSize;
+zRec = (char*)pC->aRow;
+}else if( pC->isIndex ){
+i64 payloadSize64;
+sqlite3BtreeKeySize(pCrsr, &payloadSize64);
+payloadSize = payloadSize64;
+}else{
+sqlite3BtreeDataSize(pCrsr, &payloadSize);
+}
+nField = pC->nField;
+}else{
+assert( pC->pseudoTable );
+/* The record is the sole entry of a pseudo-table */
+payloadSize = pC->nData;
+zRec = pC->pData;
+pC->cacheStatus = CACHE_STALE;
+assert( payloadSize==0 || zRec!=0 );
+nField = pC->nField;
+pCrsr = 0;
+}
+/* If payloadSize is 0, then just store a NULL */
+if( payloadSize==0 ){
+assert( pDest->flags&MEM_Null );
+goto op_column_out;
+}
+if( payloadSize>db->aLimit[SQLITE_LIMIT_LENGTH] ){
+goto too_big;
+}
+assert( p2<nField );
+/* Read and parse the table header.  Store the results of the parse
+** into the record header cache fields of the cursor.
+*/
+aType = pC->aType;
+if( pC->cacheStatus==p->cacheCtr ){
+aOffset = pC->aOffset;
+}else{
+u8 *zIdx;        /* Index into header */
+u8 *zEndHdr;     /* Pointer to first byte after the header */
+u32 offset;      /* Offset into the data */
+int szHdrSz;     /* Size of the header size field at start of record */
+int avail;       /* Number of bytes of available data */
+assert(aType);
+pC->aOffset = aOffset = &aType[nField];
+pC->payloadSize = payloadSize;
+pC->cacheStatus = p->cacheCtr;
+/* Figure out how many bytes are in the header */
+if( zRec ){
+zData = zRec;
+}else{
+if( pC->isIndex ){
+zData = (char*)sqlite3BtreeKeyFetch(pCrsr, &avail);
+}else{
+zData = (char*)sqlite3BtreeDataFetch(pCrsr, &avail);
+}
+/* If KeyFetch()/DataFetch() managed to get the entire payload,
+** save the payload in the pC->aRow cache.  That will save us from
+** having to make additional calls to fetch the content portion of
+** the record.
+*/
+if( avail>=payloadSize ){
+zRec = zData;
+pC->aRow = (u8*)zData;
+}else{
+pC->aRow = 0;
+}
+}
+/* The following assert is true in all cases accept when
+** the database file has been corrupted externally.
+**    assert( zRec!=0 || avail>=payloadSize || avail>=9 ); */
+szHdrSz = getVarint32((u8*)zData, offset);
+/* The KeyFetch() or DataFetch() above are fast and will get the entire
+** record header in most cases.  But they will fail to get the complete
+** record header if the record header does not fit on a single page
+** in the B-Tree.  When that happens, use sqlite3VdbeMemFromBtree() to
+** acquire the complete header text.
+*/
+if( !zRec && avail<offset ){
+sMem.flags = 0;
+sMem.db = 0;
+rc = sqlite3VdbeMemFromBtree(pCrsr, 0, offset, pC->isIndex, &sMem);
+if( rc!=SQLITE_OK ){
+goto op_column_out;
+}
+zData = sMem.z;
+}
+zEndHdr = (u8 *)&zData[offset];
+zIdx = (u8 *)&zData[szHdrSz];
+/* Scan the header and use it to fill in the aType[] and aOffset[]
+** arrays.  aType[i] will contain the type integer for the i-th
+** column and aOffset[i] will contain the offset from the beginning
+** of the record to the start of the data for the i-th column
+*/
+for(i=0; i<nField; i++){
+if( zIdx<zEndHdr ){
+aOffset[i] = offset;
+zIdx += getVarint32(zIdx, aType[i]);
+offset += sqlite3VdbeSerialTypeLen(aType[i]);
+}else{
+/* If i is less that nField, then there are less fields in this
+** record than SetNumColumns indicated there are columns in the
+** table. Set the offset for any extra columns not present in
+** the record to 0. This tells code below to store a NULL
+** instead of deserializing a value from the record.
+*/
+aOffset[i] = 0;
+}
+}
+sqlite3VdbeMemRelease(&sMem);
+sMem.flags = MEM_Null;
+/* If we have read more header data than was contained in the header,
+** or if the end of the last field appears to be past the end of the
+** record, or if the end of the last field appears to be before the end
+** of the record (when all fields present), then we must be dealing
+** with a corrupt database.
+*/
+if( zIdx>zEndHdr || offset>payloadSize
+|| (zIdx==zEndHdr && offset!=payloadSize) ){
+rc = SQLITE_CORRUPT_BKPT;
+goto op_column_out;
+}
+}
+/* Get the column information. If aOffset[p2] is non-zero, then
+** deserialize the value from the record. If aOffset[p2] is zero,
+** then there are not enough fields in the record to satisfy the
+** request.  In this case, set the value NULL or to P4 if P4 is
+** a pointer to a Mem object.
+*/
+if( aOffset[p2] ){
+assert( rc==SQLITE_OK );
+if( zRec ){
+sqlite3VdbeMemReleaseExternal(pDest);
+sqlite3VdbeSerialGet((u8 *)&zRec[aOffset[p2]], aType[p2], pDest);
+}else{
+len = sqlite3VdbeSerialTypeLen(aType[p2]);
+sqlite3VdbeMemMove(&sMem, pDest);
+rc = sqlite3VdbeMemFromBtree(pCrsr, aOffset[p2], len, pC->isIndex, &sMem);
+if( rc!=SQLITE_OK ){
+goto op_column_out;
+}
+zData = sMem.z;
+sqlite3VdbeSerialGet((u8*)zData, aType[p2], pDest);
+}
+pDest->enc = encoding;
+}else{
+if( pOp->p4type==P4_MEM ){
+sqlite3VdbeMemShallowCopy(pDest, pOp->p4.pMem, MEM_Static);
+}else{
+assert( pDest->flags&MEM_Null );
+}
+}
+/* If we dynamically allocated space to hold the data (in the
+** sqlite3VdbeMemFromBtree() call above) then transfer control of that
+** dynamically allocated space over to the pDest structure.
+** This prevents a memory copy.
+*/
+if( sMem.zMalloc ){
+assert( sMem.z==sMem.zMalloc );
+assert( !(pDest->flags & MEM_Dyn) );
+assert( !(pDest->flags & (MEM_Blob|MEM_Str)) || pDest->z==sMem.z );
+pDest->flags &= ~(MEM_Ephem|MEM_Static);
+pDest->flags |= MEM_Term;
+pDest->z = sMem.z;
+pDest->zMalloc = sMem.zMalloc;
+}
+rc = sqlite3VdbeMemMakeWriteable(pDest);
+op_column_out:
+UPDATE_MAX_BLOBSIZE(pDest);
+REGISTER_TRACE(pOp->p3, pDest);
+break;
+}
+/* Opcode: Affinity P1 P2 * P4 *
+**
+** Apply affinities to a range of P2 registers starting with P1.
+**
+** P4 is a string that is P2 characters long. The nth character of the
+** string indicates the column affinity that should be used for the nth
+** memory cell in the range.
+*/
+case OP_Affinity: {
+char *zAffinity = pOp->p4.z;
+Mem *pData0 = &p->aMem[pOp->p1];
+Mem *pLast = &pData0[pOp->p2-1];
+Mem *pRec;
+for(pRec=pData0; pRec<=pLast; pRec++){
+ExpandBlob(pRec);
+applyAffinity(pRec, zAffinity[pRec-pData0], encoding);
+}
+break;
+}
+/* Opcode: MakeRecord P1 P2 P3 P4 *
+**
+** Convert P2 registers beginning with P1 into a single entry
+** suitable for use as a data record in a database table or as a key
+** in an index.  The details of the format are irrelevant as long as
+** the OP_Column opcode can decode the record later.
+** Refer to source code comments for the details of the record
+** format.
+**
+** P4 may be a string that is P2 characters long.  The nth character of the
+** string indicates the column affinity that should be used for the nth
+** field of the index key.
+**
+** The mapping from character to affinity is given by the SQLITE_AFF_
+** macros defined in sqliteInt.h.
+**
+** If P4 is NULL then all index fields have the affinity NONE.
+*/
+case OP_MakeRecord: {
+/* Assuming the record contains N fields, the record format looks
+** like this:
+**
+** ------------------------------------------------------------------------
+** | hdr-size | type 0 | type 1 | ... | type N-1 | data0 | ... | data N-1 |
+** ------------------------------------------------------------------------
+**
+** Data(0) is taken from register P1.  Data(1) comes from register P1+1
+** and so froth.
+**
+** Each type field is a varint representing the serial type of the
+** corresponding data element (see sqlite3VdbeSerialType()). The
+** hdr-size field is also a varint which is the offset from the beginning
+** of the record to data0.
+*/
+u8 *zNewRecord;        /* A buffer to hold the data for the new record */
+Mem *pRec;             /* The new record */
+u64 nData = 0;         /* Number of bytes of data space */
+int nHdr = 0;          /* Number of bytes of header space */
+u64 nByte = 0;         /* Data space required for this record */
+int nZero = 0;         /* Number of zero bytes at the end of the record */
+int nVarint;           /* Number of bytes in a varint */
+u32 serial_type;       /* Type field */
+Mem *pData0;           /* First field to be combined into the record */
+Mem *pLast;            /* Last field of the record */
+int nField;            /* Number of fields in the record */
+char *zAffinity;       /* The affinity string for the record */
+int file_format;       /* File format to use for encoding */
+int i;                 /* Space used in zNewRecord[] */
+nField = pOp->p1;
+zAffinity = pOp->p4.z;
+assert( nField>0 && pOp->p2>0 && pOp->p2+nField<=p->nMem );
+pData0 = &p->aMem[nField];
+nField = pOp->p2;
+pLast = &pData0[nField-1];
+file_format = p->minWriteFileFormat;
+/* Loop through the elements that will make up the record to figure
+** out how much space is required for the new record.
+*/
+for(pRec=pData0; pRec<=pLast; pRec++){
+int len;
+if( zAffinity ){
+applyAffinity(pRec, zAffinity[pRec-pData0], encoding);
+}
+if( pRec->flags&MEM_Zero && pRec->n>0 ){
+sqlite3VdbeMemExpandBlob(pRec);
+}
+serial_type = sqlite3VdbeSerialType(pRec, file_format);
+len = sqlite3VdbeSerialTypeLen(serial_type);
+nData += len;
+nHdr += sqlite3VarintLen(serial_type);
+if( pRec->flags & MEM_Zero ){
+/* Only pure zero-filled BLOBs can be input to this Opcode.
+** We do not allow blobs with a prefix and a zero-filled tail. */
+nZero += pRec->u.i;
+}else if( len ){
+nZero = 0;
+}
+}
+/* Add the initial header varint and total the size */
+nHdr += nVarint = sqlite3VarintLen(nHdr);
+if( nVarint<sqlite3VarintLen(nHdr) ){
+nHdr++;
+}
+nByte = nHdr+nData-nZero;
+if( nByte>db->aLimit[SQLITE_LIMIT_LENGTH] ){
+goto too_big;
+}
+/* Make sure the output register has a buffer large enough to store
+** the new record. The output register (pOp->p3) is not allowed to
+** be one of the input registers (because the following call to
+** sqlite3VdbeMemGrow() could clobber the value before it is used).
+*/
+assert( pOp->p3<pOp->p1 || pOp->p3>=pOp->p1+pOp->p2 );
+pOut = &p->aMem[pOp->p3];
+if( sqlite3VdbeMemGrow(pOut, nByte, 0) ){
+goto no_mem;
+}
+zNewRecord = (u8 *)pOut->z;
+/* Write the record */
+i = putVarint32(zNewRecord, nHdr);
+for(pRec=pData0; pRec<=pLast; pRec++){
+serial_type = sqlite3VdbeSerialType(pRec, file_format);
+i += putVarint32(&zNewRecord[i], serial_type);      /* serial type */
+}
+for(pRec=pData0; pRec<=pLast; pRec++){  /* serial data */
+i += sqlite3VdbeSerialPut(&zNewRecord[i], nByte-i, pRec, file_format);
+}
+assert( i==nByte );
+assert( pOp->p3>0 && pOp->p3<=p->nMem );
+pOut->n = nByte;
+pOut->flags = MEM_Blob | MEM_Dyn;
+pOut->xDel = 0;
+if( nZero ){
+pOut->u.i = nZero;
+pOut->flags |= MEM_Zero;
+}
+pOut->enc = SQLITE_UTF8;  /* In case the blob is ever converted to text */
+REGISTER_TRACE(pOp->p3, pOut);
+UPDATE_MAX_BLOBSIZE(pOut);
+break;
+}
+/* Opcode: Statement P1 * * * *
+**
+** Begin an individual statement transaction which is part of a larger
+** transaction.  This is needed so that the statement
+** can be rolled back after an error without having to roll back the
+** entire transaction.  The statement transaction will automatically
+** commit when the VDBE halts.
+**
+** If the database connection is currently in autocommit mode (that
+** is to say, if it is in between BEGIN and COMMIT)
+** and if there are no other active statements on the same database
+** connection, then this operation is a no-op.  No statement transaction
+** is needed since any error can use the normal ROLLBACK process to
+** undo changes.
+**
+** If a statement transaction is started, then a statement journal file
+** will be allocated and initialized.
+**
+** The statement is begun on the database file with index P1.  The main
+** database file has an index of 0 and the file used for temporary tables
+** has an index of 1.
+*/
+case OP_Statement: {
+if( db->autoCommit==0 || db->activeVdbeCnt>1 ){
+int i = pOp->p1;
+Btree *pBt;
+assert( i>=0 && i<db->nDb );
+assert( db->aDb[i].pBt!=0 );
+pBt = db->aDb[i].pBt;
+assert( sqlite3BtreeIsInTrans(pBt) );
+assert( (p->btreeMask & (1<<i))!=0 );
+if( !sqlite3BtreeIsInStmt(pBt) ){
+rc = sqlite3BtreeBeginStmt(pBt);
+p->openedStatement = 1;
+}
+}
+break;
+}
+/* Opcode: AutoCommit P1 P2 * * *
+**
+** Set the database auto-commit flag to P1 (1 or 0). If P2 is true, roll
+** back any currently active btree transactions. If there are any active
+** VMs (apart from this one), then the COMMIT or ROLLBACK statement fails.
+**
+** This instruction causes the VM to halt.
+*/
+case OP_AutoCommit: {
+u8 i = pOp->p1;
+u8 rollback = pOp->p2;
+assert( i==1 || i==0 );
+assert( i==1 || rollback==0 );
+assert( db->activeVdbeCnt>0 );  /* At least this one VM is active */
+if( db->activeVdbeCnt>1 && i && !db->autoCommit ){
+/* If this instruction implements a COMMIT or ROLLBACK, other VMs are
+** still running, and a transaction is active, return an error indicating
+** that the other VMs must complete first.
+*/
+sqlite3SetString(&p->zErrMsg, db, "cannot %s transaction - "
+"SQL statements in progress",
+rollback ? "rollback" : "commit");
+rc = SQLITE_ERROR;
+}else if( i!=db->autoCommit ){
+if( pOp->p2 ){
+assert( i==1 );
+sqlite3RollbackAll(db);
+db->autoCommit = 1;
+}else{
+db->autoCommit = i;
+if( sqlite3VdbeHalt(p)==SQLITE_BUSY ){
+p->pc = pc;
+db->autoCommit = 1-i;
+p->rc = rc = SQLITE_BUSY;
+goto vdbe_return;
+}
+}
+if( p->rc==SQLITE_OK ){
+rc = SQLITE_DONE;
+}else{
+rc = SQLITE_ERROR;
+}
+goto vdbe_return;
+}else{
+sqlite3SetString(&p->zErrMsg, db,
+(!i)?"cannot start a transaction within a transaction":(
+(rollback)?"cannot rollback - no transaction is active":
+"cannot commit - no transaction is active"));
+rc = SQLITE_ERROR;
+}
+break;
+}
+/* Opcode: Transaction P1 P2 * * *
+**
+** Begin a transaction.  The transaction ends when a Commit or Rollback
+** opcode is encountered.  Depending on the ON CONFLICT setting, the
+** transaction might also be rolled back if an error is encountered.
+**
+** P1 is the index of the database file on which the transaction is
+** started.  Index 0 is the main database file and index 1 is the
+** file used for temporary tables.  Indices of 2 or more are used for
+** attached databases.
+**
+** If P2 is non-zero, then a write-transaction is started.  A RESERVED lock is
+** obtained on the database file when a write-transaction is started.  No
+** other process can start another write transaction while this transaction is
+** underway.  Starting a write transaction also creates a rollback journal. A
+** write transaction must be started before any changes can be made to the
+** database.  If P2 is 2 or greater then an EXCLUSIVE lock is also obtained
+** on the file.
+**
+** If P2 is zero, then a read-lock is obtained on the database file.
+*/
+case OP_Transaction: {
+int i = pOp->p1;
+Btree *pBt;
+assert( i>=0 && i<db->nDb );
+assert( (p->btreeMask & (1<<i))!=0 );
+pBt = db->aDb[i].pBt;
+if( pBt ){
+rc = sqlite3BtreeBeginTrans(pBt, pOp->p2);
+if( rc==SQLITE_BUSY ){
+p->pc = pc;
+p->rc = rc = SQLITE_BUSY;
+goto vdbe_return;
+}
+if( rc!=SQLITE_OK && rc!=SQLITE_READONLY /* && rc!=SQLITE_BUSY */ ){
+goto abort_due_to_error;
+}
+}
+break;
+}
+/* Opcode: ReadCookie P1 P2 P3 * *
+**
+** Read cookie number P3 from database P1 and write it into register P2.
+** P3==0 is the schema version.  P3==1 is the database format.
+** P3==2 is the recommended pager cache size, and so forth.  P1==0 is
+** the main database file and P1==1 is the database file used to store
+** temporary tables.
+**
+** If P1 is negative, then this is a request to read the size of a
+** databases free-list. P3 must be set to 1 in this case. The actual
+** database accessed is ((P1+1)*-1). For example, a P1 parameter of -1
+** corresponds to database 0 ("main"), a P1 of -2 is database 1 ("temp").
+**
+** There must be a read-lock on the database (either a transaction
+** must be started or there must be an open cursor) before
+** executing this instruction.
+*/
+case OP_ReadCookie: {               /* out2-prerelease */
+int iMeta;
+int iDb = pOp->p1;
+int iCookie = pOp->p3;
+assert( pOp->p3<SQLITE_N_BTREE_META );
+if( iDb<0 ){
+iDb = (-1*(iDb+1));
+iCookie *= -1;
+}
+assert( iDb>=0 && iDb<db->nDb );
+assert( db->aDb[iDb].pBt!=0 );
+assert( (p->btreeMask & (1<<iDb))!=0 );
+/* The indexing of meta values at the schema layer is off by one from
+** the indexing in the btree layer.  The btree considers meta[0] to
+** be the number of free pages in the database (a read-only value)
+** and meta[1] to be the schema cookie.  The schema layer considers
+** meta[1] to be the schema cookie.  So we have to shift the index
+** by one in the following statement.
+*/
+rc = sqlite3BtreeGetMeta(db->aDb[iDb].pBt, 1 + iCookie, (u32 *)&iMeta);
+pOut->u.i = iMeta;
+MemSetTypeFlag(pOut, MEM_Int);
+break;
+}
+/* Opcode: SetCookie P1 P2 P3 * *
+**
+** Write the content of register P3 (interpreted as an integer)
+** into cookie number P2 of database P1.
+** P2==0 is the schema version.  P2==1 is the database format.
+** P2==2 is the recommended pager cache size, and so forth.  P1==0 is
+** the main database file and P1==1 is the database file used to store
+** temporary tables.
+**
+** A transaction must be started before executing this opcode.
+*/
+case OP_SetCookie: {       /* in3 */
+Db *pDb;
+assert( pOp->p2<SQLITE_N_BTREE_META );
+assert( pOp->p1>=0 && pOp->p1<db->nDb );
+assert( (p->btreeMask & (1<<pOp->p1))!=0 );
+pDb = &db->aDb[pOp->p1];
+assert( pDb->pBt!=0 );
+sqlite3VdbeMemIntegerify(pIn3);
+/* See note about index shifting on OP_ReadCookie */
+rc = sqlite3BtreeUpdateMeta(pDb->pBt, 1+pOp->p2, (int)pIn3->u.i);
+if( pOp->p2==0 ){
+/* When the schema cookie changes, record the new cookie internally */
+pDb->pSchema->schema_cookie = pIn3->u.i;
+db->flags |= SQLITE_InternChanges;
+}else if( pOp->p2==1 ){
+/* Record changes in the file format */
+pDb->pSchema->file_format = pIn3->u.i;
+}
+if( pOp->p1==1 ){
+/* Invalidate all prepared statements whenever the TEMP database
+** schema is changed.  Ticket #1644 */
+sqlite3ExpirePreparedStatements(db);
+}
+break;
+}
+/* Opcode: VerifyCookie P1 P2 *
+**
+** Check the value of global database parameter number 0 (the
+** schema version) and make sure it is equal to P2.
+** P1 is the database number which is 0 for the main database file
+** and 1 for the file holding temporary tables and some higher number
+** for auxiliary databases.
+**
+** The cookie changes its value whenever the database schema changes.
+** This operation is used to detect when that the cookie has changed
+** and that the current process needs to reread the schema.
+**
+** Either a transaction needs to have been started or an OP_Open needs
+** to be executed (to establish a read lock) before this opcode is
+** invoked.
+*/
+case OP_VerifyCookie: {
+int iMeta;
+Btree *pBt;
+assert( pOp->p1>=0 && pOp->p1<db->nDb );
+assert( (p->btreeMask & (1<<pOp->p1))!=0 );
+pBt = db->aDb[pOp->p1].pBt;
+if( pBt ){
+rc = sqlite3BtreeGetMeta(pBt, 1, (u32 *)&iMeta);
+}else{
+rc = SQLITE_OK;
+iMeta = 0;
+}
+if( rc==SQLITE_OK && iMeta!=pOp->p2 ){
+sqlite3DbFree(db, p->zErrMsg);
+p->zErrMsg = sqlite3DbStrDup(db, "database schema has changed");
+/* If the schema-cookie from the database file matches the cookie
+** stored with the in-memory representation of the schema, do
+** not reload the schema from the database file.
+**
+** If virtual-tables are in use, this is not just an optimization.
+** Often, v-tables store their data in other SQLite tables, which
+** are queried from within xNext() and other v-table methods using
+** prepared queries. If such a query is out-of-date, we do not want to
+** discard the database schema, as the user code implementing the
+** v-table would have to be ready for the sqlite3_vtab structure itself
+** to be invalidated whenever sqlite3_step() is called from within
+** a v-table method.
+*/
+if( db->aDb[pOp->p1].pSchema->schema_cookie!=iMeta ){
+sqlite3ResetInternalSchema(db, pOp->p1);
+}
+sqlite3ExpirePreparedStatements(db);
+rc = SQLITE_SCHEMA;
+}
+break;
+}
+/* Opcode: OpenRead P1 P2 P3 P4 P5
+**
+** Open a read-only cursor for the database table whose root page is
+** P2 in a database file.  The database file is determined by P3.
+** P3==0 means the main database, P3==1 means the database used for
+** temporary tables, and P3>1 means used the corresponding attached
+** database.  Give the new cursor an identifier of P1.  The P1
+** values need not be contiguous but all P1 values should be small integers.
+** It is an error for P1 to be negative.
+**
+** If P5!=0 then use the content of register P2 as the root page, not
+** the value of P2 itself.
+**
+** There will be a read lock on the database whenever there is an
+** open cursor.  If the database was unlocked prior to this instruction
+** then a read lock is acquired as part of this instruction.  A read
+** lock allows other processes to read the database but prohibits
+** any other process from modifying the database.  The read lock is
+** released when all cursors are closed.  If this instruction attempts
+** to get a read lock but fails, the script terminates with an
+** SQLITE_BUSY error code.
+**
+** The P4 value is a pointer to a KeyInfo structure that defines the
+** content and collating sequence of indices.  P4 is NULL for cursors
+** that are not pointing to indices.
+**
+** See also OpenWrite.
+*/
+/* Opcode: OpenWrite P1 P2 P3 P4 P5
+**
+** Open a read/write cursor named P1 on the table or index whose root
+** page is P2.  Or if P5!=0 use the content of register P2 to find the
+** root page.
+**
+** The P4 value is a pointer to a KeyInfo structure that defines the
+** content and collating sequence of indices.  P4 is NULL for cursors
+** that are not pointing to indices.
+**
+** This instruction works just like OpenRead except that it opens the cursor
+** in read/write mode.  For a given table, there can be one or more read-only
+** cursors or a single read/write cursor but not both.
+**
+** See also OpenRead.
+*/
+case OP_OpenRead:
+case OP_OpenWrite: {
+int i = pOp->p1;
+int p2 = pOp->p2;
+int iDb = pOp->p3;
+int wrFlag;
+Btree *pX;
+Cursor *pCur;
+Db *pDb;
+assert( iDb>=0 && iDb<db->nDb );
+assert( (p->btreeMask & (1<<iDb))!=0 );
+pDb = &db->aDb[iDb];
+pX = pDb->pBt;
+assert( pX!=0 );
+if( pOp->opcode==OP_OpenWrite ){
+wrFlag = 1;
+if( pDb->pSchema->file_format < p->minWriteFileFormat ){
+p->minWriteFileFormat = pDb->pSchema->file_format;
+}
+}else{
+wrFlag = 0;
+}
+if( pOp->p5 ){
+assert( p2>0 );
+assert( p2<=p->nMem );
+pIn2 = &p->aMem[p2];
+sqlite3VdbeMemIntegerify(pIn2);
+p2 = pIn2->u.i;
+assert( p2>=2 );
+}
+assert( i>=0 );
+pCur = allocateCursor(p, i, &pOp[-1], iDb, 1);
+if( pCur==0 ) goto no_mem;
+pCur->nullRow = 1;
+rc = sqlite3BtreeCursor(pX, p2, wrFlag, pOp->p4.p, pCur->pCursor);
+if( pOp->p4type==P4_KEYINFO ){
+pCur->pKeyInfo = pOp->p4.pKeyInfo;
+pCur->pKeyInfo->enc = ENC(p->db);
+}else{
+pCur->pKeyInfo = 0;
+}
+switch( rc ){
+case SQLITE_BUSY: {
+p->pc = pc;
+p->rc = rc = SQLITE_BUSY;
+goto vdbe_return;
+}
+case SQLITE_OK: {
+int flags = sqlite3BtreeFlags(pCur->pCursor);
+/* Sanity checking.  Only the lower four bits of the flags byte should
+** be used.  Bit 3 (mask 0x08) is unpredictable.  The lower 3 bits
+** (mask 0x07) should be either 5 (intkey+leafdata for tables) or
+** 2 (zerodata for indices).  If these conditions are not met it can
+** only mean that we are dealing with a corrupt database file
+*/
+if( (flags & 0xf0)!=0 || ((flags & 0x07)!=5 && (flags & 0x07)!=2) ){
+rc = SQLITE_CORRUPT_BKPT;
+goto abort_due_to_error;
+}
+pCur->isTable = (flags & BTREE_INTKEY)!=0;
+pCur->isIndex = (flags & BTREE_ZERODATA)!=0;
+/* If P4==0 it means we are expected to open a table.  If P4!=0 then
+** we expect to be opening an index.  If this is not what happened,
+** then the database is corrupt
+*/
+if( (pCur->isTable && pOp->p4type==P4_KEYINFO)
+|| (pCur->isIndex && pOp->p4type!=P4_KEYINFO) ){
+rc = SQLITE_CORRUPT_BKPT;
+goto abort_due_to_error;
+}
+break;
+}
+case SQLITE_EMPTY: {
+pCur->isTable = pOp->p4type!=P4_KEYINFO;
+pCur->isIndex = !pCur->isTable;
+pCur->pCursor = 0;
+rc = SQLITE_OK;
+break;
+}
+default: {
+goto abort_due_to_error;
+}
+}
+break;
+}
+/* Opcode: OpenEphemeral P1 P2 * P4 *
+**
+** Open a new cursor P1 to a transient table.
+** The cursor is always opened read/write even if
+** the main database is read-only.  The transient or virtual
+** table is deleted automatically when the cursor is closed.
+**
+** P2 is the number of columns in the virtual table.
+** The cursor points to a BTree table if P4==0 and to a BTree index
+** if P4 is not 0.  If P4 is not NULL, it points to a KeyInfo structure
+** that defines the format of keys in the index.
+**
+** This opcode was once called OpenTemp.  But that created
+** confusion because the term "temp table", might refer either
+** to a TEMP table at the SQL level, or to a table opened by
+** this opcode.  Then this opcode was call OpenVirtual.  But
+** that created confusion with the whole virtual-table idea.
+*/
+case OP_OpenEphemeral: {
+int i = pOp->p1;
+Cursor *pCx;
+static const int openFlags =
+SQLITE_OPEN_READWRITE |
+SQLITE_OPEN_CREATE |
+SQLITE_OPEN_EXCLUSIVE |
+SQLITE_OPEN_DELETEONCLOSE |
+SQLITE_OPEN_TRANSIENT_DB;
+assert( i>=0 );
+pCx = allocateCursor(p, i, pOp, -1, 1);
+if( pCx==0 ) goto no_mem;
+pCx->nullRow = 1;
+rc = sqlite3BtreeFactory(db, 0, 1, SQLITE_DEFAULT_TEMP_CACHE_SIZE, openFlags,
+&pCx->pBt);
+if( rc==SQLITE_OK ){
+rc = sqlite3BtreeBeginTrans(pCx->pBt, 1);
+}
+if( rc==SQLITE_OK ){
+/* If a transient index is required, create it by calling
+** sqlite3BtreeCreateTable() with the BTREE_ZERODATA flag before
+** opening it. If a transient table is required, just use the
+** automatically created table with root-page 1 (an INTKEY table).
+*/
+if( pOp->p4.pKeyInfo ){
+int pgno;
+assert( pOp->p4type==P4_KEYINFO );
+rc = sqlite3BtreeCreateTable(pCx->pBt, &pgno, BTREE_ZERODATA);
+if( rc==SQLITE_OK ){
+assert( pgno==MASTER_ROOT+1 );
+rc = sqlite3BtreeCursor(pCx->pBt, pgno, 1,
+(KeyInfo*)pOp->p4.z, pCx->pCursor);
+pCx->pKeyInfo = pOp->p4.pKeyInfo;
+pCx->pKeyInfo->enc = ENC(p->db);
+}
+pCx->isTable = 0;
+}else{
+rc = sqlite3BtreeCursor(pCx->pBt, MASTER_ROOT, 1, 0, pCx->pCursor);
+pCx->isTable = 1;
+}
+}
+pCx->isIndex = !pCx->isTable;
+break;
+}
+/* Opcode: OpenPseudo P1 P2 * * *
+**
+** Open a new cursor that points to a fake table that contains a single
+** row of data.  Any attempt to write a second row of data causes the
+** first row to be deleted.  All data is deleted when the cursor is
+** closed.
+**
+** A pseudo-table created by this opcode is useful for holding the
+** NEW or OLD tables in a trigger.  Also used to hold the a single
+** row output from the sorter so that the row can be decomposed into
+** individual columns using the OP_Column opcode.
+**
+** When OP_Insert is executed to insert a row in to the pseudo table,
+** the pseudo-table cursor may or may not make it's own copy of the
+** original row data. If P2 is 0, then the pseudo-table will copy the
+** original row data. Otherwise, a pointer to the original memory cell
+** is stored. In this case, the vdbe program must ensure that the
+** memory cell containing the row data is not overwritten until the
+** pseudo table is closed (or a new row is inserted into it).
+*/
+case OP_OpenPseudo: {
+int i = pOp->p1;
+Cursor *pCx;
+assert( i>=0 );
+pCx = allocateCursor(p, i, &pOp[-1], -1, 0);
+if( pCx==0 ) goto no_mem;
+pCx->nullRow = 1;
+pCx->pseudoTable = 1;
+pCx->ephemPseudoTable = pOp->p2;
+pCx->isTable = 1;
+pCx->isIndex = 0;
+break;
+}
+/* Opcode: Close P1 * * * *
+**
+** Close a cursor previously opened as P1.  If P1 is not
+** currently open, this instruction is a no-op.
+*/
+case OP_Close: {
+int i = pOp->p1;
+assert( i>=0 && i<p->nCursor );
+sqlite3VdbeFreeCursor(p, p->apCsr[i]);
+p->apCsr[i] = 0;
+break;
+}
+/* Opcode: MoveGe P1 P2 P3 P4 *
+**
+** If cursor P1 refers to an SQL table (B-Tree that uses integer keys),
+** use the integer value in register P3 as a key. If cursor P1 refers
+** to an SQL index, then P3 is the first in an array of P4 registers
+** that are used as an unpacked index key.
+**
+** Reposition cursor P1 so that  it points to the smallest entry that
+** is greater than or equal to the key value. If there are no records
+** greater than or equal to the key and P2 is not zero, then jump to P2.
+**
+** A special feature of this opcode (and different from the
+** related OP_MoveGt, OP_MoveLt, and OP_MoveLe) is that if P2 is
+** zero and P1 is an SQL table (a b-tree with integer keys) then
+** the seek is deferred until it is actually needed.  It might be
+** the case that the cursor is never accessed.  By deferring the
+** seek, we avoid unnecessary seeks.
+**
+** See also: Found, NotFound, Distinct, MoveLt, MoveGt, MoveLe
+*/
+/* Opcode: MoveGt P1 P2 P3 P4 *
+**
+** If cursor P1 refers to an SQL table (B-Tree that uses integer keys),
+** use the integer value in register P3 as a key. If cursor P1 refers
+** to an SQL index, then P3 is the first in an array of P4 registers
+** that are used as an unpacked index key.
+**
+** Reposition cursor P1 so that  it points to the smallest entry that
+** is greater than the key value. If there are no records greater than
+** the key and P2 is not zero, then jump to P2.
+**
+** See also: Found, NotFound, Distinct, MoveLt, MoveGe, MoveLe
+*/
+/* Opcode: MoveLt P1 P2 P3 P4 *
+**
+** If cursor P1 refers to an SQL table (B-Tree that uses integer keys),
+** use the integer value in register P3 as a key. If cursor P1 refers
+** to an SQL index, then P3 is the first in an array of P4 registers
+** that are used as an unpacked index key.
+**
+** Reposition cursor P1 so that  it points to the largest entry that
+** is less than the key value. If there are no records less than
+** the key and P2 is not zero, then jump to P2.
+**
+** See also: Found, NotFound, Distinct, MoveGt, MoveGe, MoveLe
+*/
+/* Opcode: MoveLe P1 P2 P3 P4 *
+**
+** If cursor P1 refers to an SQL table (B-Tree that uses integer keys),
+** use the integer value in register P3 as a key. If cursor P1 refers
+** to an SQL index, then P3 is the first in an array of P4 registers
+** that are used as an unpacked index key.
+**
+** Reposition cursor P1 so that it points to the largest entry that
+** is less than or equal to the key value. If there are no records
+** less than or equal to the key and P2 is not zero, then jump to P2.
+**
+** See also: Found, NotFound, Distinct, MoveGt, MoveGe, MoveLt
+*/
+case OP_MoveLt:         /* jump, in3 */
+case OP_MoveLe:         /* jump, in3 */
+case OP_MoveGe:         /* jump, in3 */
+case OP_MoveGt: {       /* jump, in3 */
+int i = pOp->p1;
+Cursor *pC;
+assert( i>=0 && i<p->nCursor );
+pC = p->apCsr[i];
+assert( pC!=0 );
+if( pC->pCursor!=0 ){
+int res, oc;
+oc = pOp->opcode;
+pC->nullRow = 0;
+if( pC->isTable ){
+i64 iKey = sqlite3VdbeIntValue(pIn3);
+if( pOp->p2==0 ){
+assert( pOp->opcode==OP_MoveGe );
+pC->movetoTarget = iKey;
+pC->rowidIsValid = 0;
+pC->deferredMoveto = 1;
+break;
+}
+rc = sqlite3BtreeMovetoUnpacked(pC->pCursor, 0, (u64)iKey, 0, &res);
+if( rc!=SQLITE_OK ){
+goto abort_due_to_error;
+}
+pC->lastRowid = iKey;
+pC->rowidIsValid = res==0;
+}else{
+UnpackedRecord r;
+int nField = pOp->p4.i;
+assert( pOp->p4type==P4_INT32 );
+assert( nField>0 );
+r.pKeyInfo = pC->pKeyInfo;
+r.nField = nField;
+if( oc==OP_MoveGt || oc==OP_MoveLe ){
+r.flags = UNPACKED_INCRKEY;
+}else{
+r.flags = 0;
+}
+r.aMem = &p->aMem[pOp->p3];
+rc = sqlite3BtreeMovetoUnpacked(pC->pCursor, &r, 0, 0, &res);
+if( rc!=SQLITE_OK ){
+goto abort_due_to_error;
+}
+pC->rowidIsValid = 0;
+}
+pC->deferredMoveto = 0;
+pC->cacheStatus = CACHE_STALE;
+#ifdef SQLITE_TEST
+sqlite3_search_count++;
+#endif
+if( oc==OP_MoveGe || oc==OP_MoveGt ){
+if( res<0 ){
+rc = sqlite3BtreeNext(pC->pCursor, &res);
+if( rc!=SQLITE_OK ) goto abort_due_to_error;
+pC->rowidIsValid = 0;
+}else{
+res = 0;
+}
+}else{
+assert( oc==OP_MoveLt || oc==OP_MoveLe );
+if( res>=0 ){
+rc = sqlite3BtreePrevious(pC->pCursor, &res);
+if( rc!=SQLITE_OK ) goto abort_due_to_error;
+pC->rowidIsValid = 0;
+}else{
+/* res might be negative because the table is empty.  Check to
+** see if this is the case.
+*/
+res = sqlite3BtreeEof(pC->pCursor);
+}
+}
+assert( pOp->p2>0 );
+if( res ){
+pc = pOp->p2 - 1;
+}
+}else if( !pC->pseudoTable ){
+/* This happens when attempting to open the sqlite3_master table
+** for read access returns SQLITE_EMPTY. In this case always
+** take the jump (since there are no records in the table).
+*/
+pc = pOp->p2 - 1;
+}
+break;
+}
+/* Opcode: Found P1 P2 P3 * *
+**
+** Register P3 holds a blob constructed by MakeRecord.  P1 is an index.
+** If an entry that matches the value in register p3 exists in P1 then
+** jump to P2.  If the P3 value does not match any entry in P1
+** then fall thru.  The P1 cursor is left pointing at the matching entry
+** if it exists.
+**
+** This instruction is used to implement the IN operator where the
+** left-hand side is a SELECT statement.  P1 may be a true index, or it
+** may be a temporary index that holds the results of the SELECT
+** statement.   This instruction is also used to implement the
+** DISTINCT keyword in SELECT statements.
+**
+** This instruction checks if index P1 contains a record for which
+** the first N serialized values exactly match the N serialized values
+** in the record in register P3, where N is the total number of values in
+** the P3 record (the P3 record is a prefix of the P1 record).
+**
+** See also: NotFound, IsUnique, NotExists
+*/
+/* Opcode: NotFound P1 P2 P3 * *
+**
+** Register P3 holds a blob constructed by MakeRecord.  P1 is
+** an index.  If no entry exists in P1 that matches the blob then jump
+** to P2.  If an entry does existing, fall through.  The cursor is left
+** pointing to the entry that matches.
+**
+** See also: Found, NotExists, IsUnique
+*/
+case OP_NotFound:       /* jump, in3 */
+case OP_Found: {        /* jump, in3 */
+int i = pOp->p1;
+int alreadyExists = 0;
+Cursor *pC;
+assert( i>=0 && i<p->nCursor );
+assert( p->apCsr[i]!=0 );
+if( (pC = p->apCsr[i])->pCursor!=0 ){
+int res;
+UnpackedRecord *pIdxKey;
+assert( pC->isTable==0 );
+assert( pIn3->flags & MEM_Blob );
+pIdxKey = sqlite3VdbeRecordUnpack(pC->pKeyInfo, pIn3->n, pIn3->z,
+aTempRec, sizeof(aTempRec));
+if( pIdxKey==0 ){
+goto no_mem;
+}
+if( pOp->opcode==OP_Found ){
+pIdxKey->flags |= UNPACKED_PREFIX_MATCH;
+}
+rc = sqlite3BtreeMovetoUnpacked(pC->pCursor, pIdxKey, 0, 0, &res);
+sqlite3VdbeDeleteUnpackedRecord(pIdxKey);
+if( rc!=SQLITE_OK ){
+break;
+}
+alreadyExists = (res==0);
+pC->deferredMoveto = 0;
+pC->cacheStatus = CACHE_STALE;
+}
+if( pOp->opcode==OP_Found ){
+if( alreadyExists ) pc = pOp->p2 - 1;
+}else{
+if( !alreadyExists ) pc = pOp->p2 - 1;
+}
+break;
+}
+/* Opcode: IsUnique P1 P2 P3 P4 *
+**
+** The P3 register contains an integer record number.  Call this
+** record number R.  The P4 register contains an index key created
+** using MakeRecord.  Call it K.
+**
+** P1 is an index.  So it has no data and its key consists of a
+** record generated by OP_MakeRecord where the last field is the
+** rowid of the entry that the index refers to.
+**
+** This instruction asks if there is an entry in P1 where the
+** fields matches K but the rowid is different from R.
+** If there is no such entry, then there is an immediate
+** jump to P2.  If any entry does exist where the index string
+** matches K but the record number is not R, then the record
+** number for that entry is written into P3 and control
+** falls through to the next instruction.
+**
+** See also: NotFound, NotExists, Found
+*/
+case OP_IsUnique: {        /* jump, in3 */
+int i = pOp->p1;
+Cursor *pCx;
+BtCursor *pCrsr;
+Mem *pK;
+i64 R;
+/* Pop the value R off the top of the stack
+*/
+assert( pOp->p4type==P4_INT32 );
+assert( pOp->p4.i>0 && pOp->p4.i<=p->nMem );
+pK = &p->aMem[pOp->p4.i];
+sqlite3VdbeMemIntegerify(pIn3);
+R = pIn3->u.i;
+assert( i>=0 && i<p->nCursor );
+pCx = p->apCsr[i];
+assert( pCx!=0 );
+pCrsr = pCx->pCursor;
+if( pCrsr!=0 ){
+int res;
+i64 v;                     /* The record number that matches K */
+UnpackedRecord *pIdxKey;   /* Unpacked version of P4 */
+/* Make sure K is a string and make zKey point to K
+*/
+assert( pK->flags & MEM_Blob );
+pIdxKey = sqlite3VdbeRecordUnpack(pCx->pKeyInfo, pK->n, pK->z,
+aTempRec, sizeof(aTempRec));
+if( pIdxKey==0 ){
+goto no_mem;
+}
+pIdxKey->flags |= UNPACKED_IGNORE_ROWID;
+/* Search for an entry in P1 where all but the last rowid match K
+** If there is no such entry, jump immediately to P2.
+*/
+assert( pCx->deferredMoveto==0 );
+pCx->cacheStatus = CACHE_STALE;
+rc = sqlite3BtreeMovetoUnpacked(pCrsr, pIdxKey, 0, 0, &res);
+if( rc!=SQLITE_OK ){
+sqlite3VdbeDeleteUnpackedRecord(pIdxKey);
+goto abort_due_to_error;
+}
+if( res<0 ){
+rc = sqlite3BtreeNext(pCrsr, &res);
+if( res ){
+pc = pOp->p2 - 1;
+sqlite3VdbeDeleteUnpackedRecord(pIdxKey);
+break;
+}
+}
+rc = sqlite3VdbeIdxKeyCompare(pCx, pIdxKey, &res);
+sqlite3VdbeDeleteUnpackedRecord(pIdxKey);
+if( rc!=SQLITE_OK ) goto abort_due_to_error;
+if( res>0 ){
+pc = pOp->p2 - 1;
+break;
+}
+/* At this point, pCrsr is pointing to an entry in P1 where all but
+** the final entry (the rowid) matches K.  Check to see if the
+** final rowid column is different from R.  If it equals R then jump
+** immediately to P2.
+*/
+rc = sqlite3VdbeIdxRowid(pCrsr, &v);
+if( rc!=SQLITE_OK ){
+goto abort_due_to_error;
+}
+if( v==R ){
+pc = pOp->p2 - 1;
+break;
+}
+/* The final varint of the key is different from R.  Store it back
+** into register R3.  (The record number of an entry that violates
+** a UNIQUE constraint.)
+*/
+pIn3->u.i = v;
+assert( pIn3->flags&MEM_Int );
+}
+break;
+}
+/* Opcode: NotExists P1 P2 P3 * *
+**
+** Use the content of register P3 as a integer key.  If a record
+** with that key does not exist in table of P1, then jump to P2.
+** If the record does exist, then fall thru.  The cursor is left
+** pointing to the record if it exists.
+**
+** The difference between this operation and NotFound is that this
+** operation assumes the key is an integer and that P1 is a table whereas
+** NotFound assumes key is a blob constructed from MakeRecord and
+** P1 is an index.
+**
+** See also: Found, NotFound, IsUnique
+*/
+case OP_NotExists: {        /* jump, in3 */
+int i = pOp->p1;
+Cursor *pC;
+BtCursor *pCrsr;
+assert( i>=0 && i<p->nCursor );
+assert( p->apCsr[i]!=0 );
+if( (pCrsr = (pC = p->apCsr[i])->pCursor)!=0 ){
+int res;
+u64 iKey;
+assert( pIn3->flags & MEM_Int );
+assert( p->apCsr[i]->isTable );
+iKey = intToKey(pIn3->u.i);
+rc = sqlite3BtreeMovetoUnpacked(pCrsr, 0, iKey, 0,&res);
+pC->lastRowid = pIn3->u.i;
+pC->rowidIsValid = res==0;
+pC->nullRow = 0;
+pC->cacheStatus = CACHE_STALE;
+/* res might be uninitialized if rc!=SQLITE_OK.  But if rc!=SQLITE_OK
+** processing is about to abort so we really do not care whether or not
+** the following jump is taken.  (In other words, do not stress over
+** the error that valgrind sometimes shows on the next statement when
+** running ioerr.test and similar failure-recovery test scripts.) */
+if( res!=0 ){
+pc = pOp->p2 - 1;
+assert( pC->rowidIsValid==0 );
+}
+}else if( !pC->pseudoTable ){
+/* This happens when an attempt to open a read cursor on the
+** sqlite_master table returns SQLITE_EMPTY.
+*/
+assert( pC->isTable );
+pc = pOp->p2 - 1;
+assert( pC->rowidIsValid==0 );
+}
+break;
+}
+/* Opcode: Sequence P1 P2 * * *
+**
+** Find the next available sequence number for cursor P1.
+** Write the sequence number into register P2.
+** The sequence number on the cursor is incremented after this
+** instruction.
+*/
+case OP_Sequence: {           /* out2-prerelease */
+int i = pOp->p1;
+assert( i>=0 && i<p->nCursor );
+assert( p->apCsr[i]!=0 );
+pOut->u.i = p->apCsr[i]->seqCount++;
+MemSetTypeFlag(pOut, MEM_Int);
+break;
+}
+/* Opcode: NewRowid P1 P2 P3 * *
+**
+** Get a new integer record number (a.k.a "rowid") used as the key to a table.
+** The record number is not previously used as a key in the database
+** table that cursor P1 points to.  The new record number is written
+** written to register P2.
+**
+** If P3>0 then P3 is a register that holds the largest previously
+** generated record number.  No new record numbers are allowed to be less
+** than this value.  When this value reaches its maximum, a SQLITE_FULL
+** error is generated.  The P3 register is updated with the generated
+** record number.  This P3 mechanism is used to help implement the
+** AUTOINCREMENT feature.
+*/
+case OP_NewRowid: {           /* out2-prerelease */
+int i = pOp->p1;
+i64 v = 0;
+Cursor *pC;
+assert( i>=0 && i<p->nCursor );
+assert( p->apCsr[i]!=0 );
+if( (pC = p->apCsr[i])->pCursor==0 ){
+/* The zero initialization above is all that is needed */
+}else{
+/* The next rowid or record number (different terms for the same
+** thing) is obtained in a two-step algorithm.
+**
+** First we attempt to find the largest existing rowid and add one
+** to that.  But if the largest existing rowid is already the maximum
+** positive integer, we have to fall through to the second
+** probabilistic algorithm
+**
+** The second algorithm is to select a rowid at random and see if
+** it already exists in the table.  If it does not exist, we have
+** succeeded.  If the random rowid does exist, we select a new one
+** and try again, up to 1000 times.
+**
+** For a table with less than 2 billion entries, the probability
+** of not finding a unused rowid is about 1.0e-300.  This is a
+** non-zero probability, but it is still vanishingly small and should
+** never cause a problem.  You are much, much more likely to have a
+** hardware failure than for this algorithm to fail.
+**
+** The analysis in the previous paragraph assumes that you have a good
+** source of random numbers.  Is a library function like lrand48()
+** good enough?  Maybe. Maybe not. It's hard to know whether there
+** might be subtle bugs is some implementations of lrand48() that
+** could cause problems. To avoid uncertainty, SQLite uses its own
+** random number generator based on the RC4 algorithm.
+**
+** To promote locality of reference for repetitive inserts, the
+** first few attempts at choosing a random rowid pick values just a little
+** larger than the previous rowid.  This has been shown experimentally
+** to double the speed of the COPY operation.
+*/
+int res, rx=SQLITE_OK, cnt;
+i64 x;
+cnt = 0;
+if( (sqlite3BtreeFlags(pC->pCursor)&(BTREE_INTKEY|BTREE_ZERODATA)) !=
+BTREE_INTKEY ){
+rc = SQLITE_CORRUPT_BKPT;
+goto abort_due_to_error;
+}
+assert( (sqlite3BtreeFlags(pC->pCursor) & BTREE_INTKEY)!=0 );
+assert( (sqlite3BtreeFlags(pC->pCursor) & BTREE_ZERODATA)==0 );
+#ifdef SQLITE_32BIT_ROWID
+#   define MAX_ROWID 0x7fffffff
+#else
+/* Some compilers complain about constants of the form 0x7fffffffffffffff.
+** Others complain about 0x7ffffffffffffffffLL.  The following macro seems
+** to provide the constant while making all compilers happy.
+*/
+#   define MAX_ROWID  ( (((u64)0x7fffffff)<<32) | (u64)0xffffffff )
+#endif
+if( !pC->useRandomRowid ){
+if( pC->nextRowidValid ){
+v = pC->nextRowid;
+}else{
+rc = sqlite3BtreeLast(pC->pCursor, &res);
+if( rc!=SQLITE_OK ){
+goto abort_due_to_error;
+}
+if( res ){
+v = 1;
+}else{
+sqlite3BtreeKeySize(pC->pCursor, &v);
+v = keyToInt(v);
+if( v==MAX_ROWID ){
+pC->useRandomRowid = 1;
+}else{
+v++;
+}
+}
+}
+#ifndef SQLITE_OMIT_AUTOINCREMENT
+if( pOp->p3 ){
+Mem *pMem;
+assert( pOp->p3>0 && pOp->p3<=p->nMem ); /* P3 is a valid memory cell */
+pMem = &p->aMem[pOp->p3];
+	REGISTER_TRACE(pOp->p3, pMem);
+sqlite3VdbeMemIntegerify(pMem);
+assert( (pMem->flags & MEM_Int)!=0 );  /* mem(P3) holds an integer */
+if( pMem->u.i==MAX_ROWID || pC->useRandomRowid ){
+rc = SQLITE_FULL;
+goto abort_due_to_error;
+}
+if( v<pMem->u.i+1 ){
+v = pMem->u.i + 1;
+}
+pMem->u.i = v;
+}
+#endif
+if( v<MAX_ROWID ){
+pC->nextRowidValid = 1;
+pC->nextRowid = v+1;
+}else{
+pC->nextRowidValid = 0;
+}
+}
+if( pC->useRandomRowid ){
+assert( pOp->p3==0 );  /* SQLITE_FULL must have occurred prior to this */
+v = db->priorNewRowid;
+cnt = 0;
+do{
+if( cnt==0 && (v&0xffffff)==v ){
+v++;
+}else{
+sqlite3_randomness(sizeof(v), &v);
+if( cnt<5 ) v &= 0xffffff;
+}
+if( v==0 ) continue;
+x = intToKey(v);
+rx = sqlite3BtreeMovetoUnpacked(pC->pCursor, 0, (u64)x, 0, &res);
+cnt++;
+}while( cnt<100 && rx==SQLITE_OK && res==0 );
+db->priorNewRowid = v;
+if( rx==SQLITE_OK && res==0 ){
+rc = SQLITE_FULL;
+goto abort_due_to_error;
+}
+}
+pC->rowidIsValid = 0;
+pC->deferredMoveto = 0;
+pC->cacheStatus = CACHE_STALE;
+}
+MemSetTypeFlag(pOut, MEM_Int);
+pOut->u.i = v;
+break;
+}
+/* Opcode: Insert P1 P2 P3 P4 P5
+**
+** Write an entry into the table of cursor P1.  A new entry is
+** created if it doesn't already exist or the data for an existing
+** entry is overwritten.  The data is the value stored register
+** number P2. The key is stored in register P3. The key must
+** be an integer.
+**
+** If the OPFLAG_NCHANGE flag of P5 is set, then the row change count is
+** incremented (otherwise not).  If the OPFLAG_LASTROWID flag of P5 is set,
+** then rowid is stored for subsequent return by the
+** sqlite3_last_insert_rowid() function (otherwise it is unmodified).
+**
+** Parameter P4 may point to a string containing the table-name, or
+** may be NULL. If it is not NULL, then the update-hook
+** (sqlite3.xUpdateCallback) is invoked following a successful insert.
+**
+** (WARNING/TODO: If P1 is a pseudo-cursor and P2 is dynamically
+** allocated, then ownership of P2 is transferred to the pseudo-cursor
+** and register P2 becomes ephemeral.  If the cursor is changed, the
+** value of register P2 will then change.  Make sure this does not
+** cause any problems.)
+**
+** This instruction only works on tables.  The equivalent instruction
+** for indices is OP_IdxInsert.
+*/
+case OP_Insert: {
+Mem *pData = &p->aMem[pOp->p2];
+Mem *pKey = &p->aMem[pOp->p3];
+i64 iKey;   /* The integer ROWID or key for the record to be inserted */
+int i = pOp->p1;
+Cursor *pC;
+assert( i>=0 && i<p->nCursor );
+pC = p->apCsr[i];
+assert( pC!=0 );
+assert( pC->pCursor!=0 || pC->pseudoTable );
+assert( pKey->flags & MEM_Int );
+assert( pC->isTable );
+REGISTER_TRACE(pOp->p2, pData);
+REGISTER_TRACE(pOp->p3, pKey);
+iKey = intToKey(pKey->u.i);
+if( pOp->p5 & OPFLAG_NCHANGE ) p->nChange++;
+if( pOp->p5 & OPFLAG_LASTROWID ) db->lastRowid = pKey->u.i;
+if( pC->nextRowidValid && pKey->u.i>=pC->nextRowid ){
+pC->nextRowidValid = 0;
+}
+if( pData->flags & MEM_Null ){
+pData->z = 0;
+pData->n = 0;
+}else{
+assert( pData->flags & (MEM_Blob|MEM_Str) );
+}
+if( pC->pseudoTable ){
+if( !pC->ephemPseudoTable ){
+sqlite3DbFree(db, pC->pData);
+}
+pC->iKey = iKey;
+pC->nData = pData->n;
+if( pData->z==pData->zMalloc || pC->ephemPseudoTable ){
+pC->pData = pData->z;
+if( !pC->ephemPseudoTable ){
+pData->flags &= ~MEM_Dyn;
+pData->flags |= MEM_Ephem;
+pData->zMalloc = 0;
+}
+}else{
+pC->pData = sqlite3Malloc( pC->nData+2 );
+if( !pC->pData ) goto no_mem;
+memcpy(pC->pData, pData->z, pC->nData);
+pC->pData[pC->nData] = 0;
+pC->pData[pC->nData+1] = 0;
+}
+pC->nullRow = 0;
+}else{
+int nZero;
+if( pData->flags & MEM_Zero ){
+nZero = pData->u.i;
+}else{
+nZero = 0;
+}
+rc = sqlite3BtreeInsert(pC->pCursor, 0, iKey,
+pData->z, pData->n, nZero,
+pOp->p5 & OPFLAG_APPEND);
+}
+pC->rowidIsValid = 0;
+pC->deferredMoveto = 0;
+pC->cacheStatus = CACHE_STALE;
+/* Invoke the update-hook if required. */
+if( rc==SQLITE_OK && db->xUpdateCallback && pOp->p4.z ){
+const char *zDb = db->aDb[pC->iDb].zName;
+const char *zTbl = pOp->p4.z;
+int op = ((pOp->p5 & OPFLAG_ISUPDATE) ? SQLITE_UPDATE : SQLITE_INSERT);
+assert( pC->isTable );
+db->xUpdateCallback(db->pUpdateArg, op, zDb, zTbl, iKey);
+assert( pC->iDb>=0 );
+}
+break;
+}
+/* Opcode: Delete P1 P2 * P4 *
+**
+** Delete the record at which the P1 cursor is currently pointing.
+**
+** The cursor will be left pointing at either the next or the previous
+** record in the table. If it is left pointing at the next record, then
+** the next Next instruction will be a no-op.  Hence it is OK to delete
+** a record from within an Next loop.
+**
+** If the OPFLAG_NCHANGE flag of P2 is set, then the row change count is
+** incremented (otherwise not).
+**
+** P1 must not be pseudo-table.  It has to be a real table with
+** multiple rows.
+**
+** If P4 is not NULL, then it is the name of the table that P1 is
+** pointing to.  The update hook will be invoked, if it exists.
+** If P4 is not NULL then the P1 cursor must have been positioned
+** using OP_NotFound prior to invoking this opcode.
+*/
+case OP_Delete: {
+int i = pOp->p1;
+i64 iKey;
+Cursor *pC;
+assert( i>=0 && i<p->nCursor );
+pC = p->apCsr[i];
+assert( pC!=0 );
+assert( pC->pCursor!=0 );  /* Only valid for real tables, no pseudotables */
+/* If the update-hook will be invoked, set iKey to the rowid of the
+** row being deleted.
+*/
+if( db->xUpdateCallback && pOp->p4.z ){
+assert( pC->isTable );
+assert( pC->rowidIsValid );  /* lastRowid set by previous OP_NotFound */
+iKey = pC->lastRowid;
+}
+rc = sqlite3VdbeCursorMoveto(pC);
+if( rc ) goto abort_due_to_error;
+rc = sqlite3BtreeDelete(pC->pCursor);
+pC->nextRowidValid = 0;
+pC->cacheStatus = CACHE_STALE;
+/* Invoke the update-hook if required. */
+if( rc==SQLITE_OK && db->xUpdateCallback && pOp->p4.z ){
+const char *zDb = db->aDb[pC->iDb].zName;
+const char *zTbl = pOp->p4.z;
+db->xUpdateCallback(db->pUpdateArg, SQLITE_DELETE, zDb, zTbl, iKey);
+assert( pC->iDb>=0 );
+}
+if( pOp->p2 & OPFLAG_NCHANGE ) p->nChange++;
+break;
+}
+/* Opcode: ResetCount P1 * *
+**
+** This opcode resets the VMs internal change counter to 0. If P1 is true,
+** then the value of the change counter is copied to the database handle
+** change counter (returned by subsequent calls to sqlite3_changes())
+** before it is reset. This is used by trigger programs.
+*/
+case OP_ResetCount: {
+if( pOp->p1 ){
+sqlite3VdbeSetChanges(db, p->nChange);
+}
+p->nChange = 0;
+break;
+}
+/* Opcode: RowData P1 P2 * * *
+**
+** Write into register P2 the complete row data for cursor P1.
+** There is no interpretation of the data.
+** It is just copied onto the P2 register exactly as
+** it is found in the database file.
+**
+** If the P1 cursor must be pointing to a valid row (not a NULL row)
+** of a real table, not a pseudo-table.
+*/
+/* Opcode: RowKey P1 P2 * * *
+**
+** Write into register P2 the complete row key for cursor P1.
+** There is no interpretation of the data.
+** The key is copied onto the P3 register exactly as
+** it is found in the database file.
+**
+** If the P1 cursor must be pointing to a valid row (not a NULL row)
+** of a real table, not a pseudo-table.
+*/
+case OP_RowKey:
+case OP_RowData: {
+int i = pOp->p1;
+Cursor *pC;
+BtCursor *pCrsr;
+u32 n;
+pOut = &p->aMem[pOp->p2];
+/* Note that RowKey and RowData are really exactly the same instruction */
+assert( i>=0 && i<p->nCursor );
+pC = p->apCsr[i];
+assert( pC->isTable || pOp->opcode==OP_RowKey );
+assert( pC->isIndex || pOp->opcode==OP_RowData );
+assert( pC!=0 );
+assert( pC->nullRow==0 );
+assert( pC->pseudoTable==0 );
+assert( pC->pCursor!=0 );
+pCrsr = pC->pCursor;
+rc = sqlite3VdbeCursorMoveto(pC);
+if( rc ) goto abort_due_to_error;
+if( pC->isIndex ){
+i64 n64;
+assert( !pC->isTable );
+sqlite3BtreeKeySize(pCrsr, &n64);
+if( n64>db->aLimit[SQLITE_LIMIT_LENGTH] ){
+goto too_big;
+}
+n = n64;
+}else{
+sqlite3BtreeDataSize(pCrsr, &n);
+if( n>db->aLimit[SQLITE_LIMIT_LENGTH] ){
+goto too_big;
+}
+}
+if( sqlite3VdbeMemGrow(pOut, n, 0) ){
+goto no_mem;
+}
+pOut->n = n;
+MemSetTypeFlag(pOut, MEM_Blob);
+if( pC->isIndex ){
+rc = sqlite3BtreeKey(pCrsr, 0, n, pOut->z);
+}else{
+rc = sqlite3BtreeData(pCrsr, 0, n, pOut->z);
+}
+pOut->enc = SQLITE_UTF8;  /* In case the blob is ever cast to text */
+UPDATE_MAX_BLOBSIZE(pOut);
+break;
+}
+/* Opcode: Rowid P1 P2 * * *
+**
+** Store in register P2 an integer which is the key of the table entry that
+** P1 is currently point to.
+*/
+case OP_Rowid: {                 /* out2-prerelease */
+int i = pOp->p1;
+Cursor *pC;
+i64 v;
+assert( i>=0 && i<p->nCursor );
+pC = p->apCsr[i];
+assert( pC!=0 );
+rc = sqlite3VdbeCursorMoveto(pC);
+if( rc ) goto abort_due_to_error;
+if( pC->rowidIsValid ){
+v = pC->lastRowid;
+}else if( pC->pseudoTable ){
+v = keyToInt(pC->iKey);
+}else if( pC->nullRow ){
+/* Leave the rowid set to a NULL */
+break;
+}else{
+assert( pC->pCursor!=0 );
+sqlite3BtreeKeySize(pC->pCursor, &v);
+v = keyToInt(v);
+}
+pOut->u.i = v;
+MemSetTypeFlag(pOut, MEM_Int);
+break;
+}
+/* Opcode: NullRow P1 * * * *
+**
+** Move the cursor P1 to a null row.  Any OP_Column operations
+** that occur while the cursor is on the null row will always
+** write a NULL.
+*/
+case OP_NullRow: {
+int i = pOp->p1;
+Cursor *pC;
+assert( i>=0 && i<p->nCursor );
+pC = p->apCsr[i];
+assert( pC!=0 );
+pC->nullRow = 1;
+pC->rowidIsValid = 0;
+break;
+}
+/* Opcode: Last P1 P2 * * *
+**
+** The next use of the Rowid or Column or Next instruction for P1
+** will refer to the last entry in the database table or index.
+** If the table or index is empty and P2>0, then jump immediately to P2.
+** If P2 is 0 or if the table or index is not empty, fall through
+** to the following instruction.
+*/
+case OP_Last: {        /* jump */
+int i = pOp->p1;
+Cursor *pC;
+BtCursor *pCrsr;
+int res;
+assert( i>=0 && i<p->nCursor );
+pC = p->apCsr[i];
+assert( pC!=0 );
+pCrsr = pC->pCursor;
+assert( pCrsr!=0 );
+rc = sqlite3BtreeLast(pCrsr, &res);
+pC->nullRow = res;
+pC->deferredMoveto = 0;
+pC->cacheStatus = CACHE_STALE;
+if( res && pOp->p2>0 ){
+pc = pOp->p2 - 1;
+}
+break;
+}
+/* Opcode: Sort P1 P2 * * *
+**
+** This opcode does exactly the same thing as OP_Rewind except that
+** it increments an undocumented global variable used for testing.
+**
+** Sorting is accomplished by writing records into a sorting index,
+** then rewinding that index and playing it back from beginning to
+** end.  We use the OP_Sort opcode instead of OP_Rewind to do the
+** rewinding so that the global variable will be incremented and
+** regression tests can determine whether or not the optimizer is
+** correctly optimizing out sorts.
+*/
+case OP_Sort: {        /* jump */
+#ifdef SQLITE_TEST
+sqlite3_sort_count++;
+sqlite3_search_count--;
+#endif
+/* Fall through into OP_Rewind */
+}
+/* Opcode: Rewind P1 P2 * * *
+**
+** The next use of the Rowid or Column or Next instruction for P1
+** will refer to the first entry in the database table or index.
+** If the table or index is empty and P2>0, then jump immediately to P2.
+** If P2 is 0 or if the table or index is not empty, fall through
+** to the following instruction.
+*/
+case OP_Rewind: {        /* jump */
+int i = pOp->p1;
+Cursor *pC;
+BtCursor *pCrsr;
+int res;
+assert( i>=0 && i<p->nCursor );
+pC = p->apCsr[i];
+assert( pC!=0 );
+if( (pCrsr = pC->pCursor)!=0 ){
+rc = sqlite3BtreeFirst(pCrsr, &res);
+pC->atFirst = res==0;
+pC->deferredMoveto = 0;
+pC->cacheStatus = CACHE_STALE;
+}else{
+res = 1;
+}
+pC->nullRow = res;
+assert( pOp->p2>0 && pOp->p2<p->nOp );
+if( res ){
+pc = pOp->p2 - 1;
+}
+break;
+}
+/* Opcode: Next P1 P2 * * *
+**
+** Advance cursor P1 so that it points to the next key/data pair in its
+** table or index.  If there are no more key/value pairs then fall through
+** to the following instruction.  But if the cursor advance was successful,
+** jump immediately to P2.
+**
+** The P1 cursor must be for a real table, not a pseudo-table.
+**
+** See also: Prev
+*/
+/* Opcode: Prev P1 P2 * * *
+**
+** Back up cursor P1 so that it points to the previous key/data pair in its
+** table or index.  If there is no previous key/value pairs then fall through
+** to the following instruction.  But if the cursor backup was successful,
+** jump immediately to P2.
+**
+** The P1 cursor must be for a real table, not a pseudo-table.
+*/
+case OP_Prev:          /* jump */
+case OP_Next: {        /* jump */
+Cursor *pC;
+BtCursor *pCrsr;
+int res;
+CHECK_FOR_INTERRUPT;
+assert( pOp->p1>=0 && pOp->p1<p->nCursor );
+pC = p->apCsr[pOp->p1];
+if( pC==0 ){
+break;  /* See ticket #2273 */
+}
+pCrsr = pC->pCursor;
+assert( pCrsr );
+res = 1;
+assert( pC->deferredMoveto==0 );
+rc = pOp->opcode==OP_Next ? sqlite3BtreeNext(pCrsr, &res) :
+sqlite3BtreePrevious(pCrsr, &res);
+pC->nullRow = res;
+pC->cacheStatus = CACHE_STALE;
+if( res==0 ){
+pc = pOp->p2 - 1;
+#ifdef SQLITE_TEST
+sqlite3_search_count++;
+#endif
+}
+pC->rowidIsValid = 0;
+break;
+}
+/* Opcode: IdxInsert P1 P2 P3 * *
+**
+** Register P2 holds a SQL index key made using the
+** MakeIdxRec instructions.  This opcode writes that key
+** into the index P1.  Data for the entry is nil.
+**
+** P3 is a flag that provides a hint to the b-tree layer that this
+** insert is likely to be an append.
+**
+** This instruction only works for indices.  The equivalent instruction
+** for tables is OP_Insert.
+*/
+case OP_IdxInsert: {        /* in2 */
+int i = pOp->p1;
+Cursor *pC;
+BtCursor *pCrsr;
+assert( i>=0 && i<p->nCursor );
+assert( p->apCsr[i]!=0 );
+assert( pIn2->flags & MEM_Blob );
+if( (pCrsr = (pC = p->apCsr[i])->pCursor)!=0 ){
+assert( pC->isTable==0 );
+rc = ExpandBlob(pIn2);
+if( rc==SQLITE_OK ){
+int nKey = pIn2->n;
+const char *zKey = pIn2->z;
+rc = sqlite3BtreeInsert(pCrsr, zKey, nKey, "", 0, 0, pOp->p3);
+assert( pC->deferredMoveto==0 );
+pC->cacheStatus = CACHE_STALE;
+}
+}
+break;
+}
+/* Opcode: IdxDeleteM P1 P2 P3 * *
+**
+** The content of P3 registers starting at register P2 form
+** an unpacked index key. This opcode removes that entry from the
+** index opened by cursor P1.
+*/
+case OP_IdxDelete: {
+int i = pOp->p1;
+Cursor *pC;
+BtCursor *pCrsr;
+assert( pOp->p3>0 );
+assert( pOp->p2>0 && pOp->p2+pOp->p3<=p->nMem );
+assert( i>=0 && i<p->nCursor );
+assert( p->apCsr[i]!=0 );
+if( (pCrsr = (pC = p->apCsr[i])->pCursor)!=0 ){
+int res;
+UnpackedRecord r;
+r.pKeyInfo = pC->pKeyInfo;
+r.nField = pOp->p3;
+r.flags = 0;
+r.aMem = &p->aMem[pOp->p2];
+rc = sqlite3BtreeMovetoUnpacked(pCrsr, &r, 0, 0, &res);
+if( rc==SQLITE_OK && res==0 ){
+rc = sqlite3BtreeDelete(pCrsr);
+}
+assert( pC->deferredMoveto==0 );
+pC->cacheStatus = CACHE_STALE;
+}
+break;
+}
+/* Opcode: IdxRowid P1 P2 * * *
+**
+** Write into register P2 an integer which is the last entry in the record at
+** the end of the index key pointed to by cursor P1.  This integer should be
+** the rowid of the table entry to which this index entry points.
+**
+** See also: Rowid, MakeIdxRec.
+*/
+case OP_IdxRowid: {              /* out2-prerelease */
+int i = pOp->p1;
+BtCursor *pCrsr;
+Cursor *pC;
+assert( i>=0 && i<p->nCursor );
+assert( p->apCsr[i]!=0 );
+if( (pCrsr = (pC = p->apCsr[i])->pCursor)!=0 ){
+i64 rowid;
+assert( pC->deferredMoveto==0 );
+assert( pC->isTable==0 );
+if( !pC->nullRow ){
+rc = sqlite3VdbeIdxRowid(pCrsr, &rowid);
+if( rc!=SQLITE_OK ){
+goto abort_due_to_error;
+}
+MemSetTypeFlag(pOut, MEM_Int);
+pOut->u.i = rowid;
+}
+}
+break;
+}
+/* Opcode: IdxGE P1 P2 P3 P4 P5
+**
+** The P4 register values beginning with P3 form an unpacked index
+** key that omits the ROWID.  Compare this key value against the index
+** that P1 is currently pointing to, ignoring the ROWID on the P1 index.
+**
+** If the P1 index entry is greater than or equal to the key value
+** then jump to P2.  Otherwise fall through to the next instruction.
+**
+** If P5 is non-zero then the key value is increased by an epsilon
+** prior to the comparison.  This make the opcode work like IdxGT except
+** that if the key from register P3 is a prefix of the key in the cursor,
+** the result is false whereas it would be true with IdxGT.
+*/
+/* Opcode: IdxLT P1 P2 P3 * P5
+**
+** The P4 register values beginning with P3 form an unpacked index
+** key that omits the ROWID.  Compare this key value against the index
+** that P1 is currently pointing to, ignoring the ROWID on the P1 index.
+**
+** If the P1 index entry is less than the key value then jump to P2.
+** Otherwise fall through to the next instruction.
+**
+** If P5 is non-zero then the key value is increased by an epsilon prior
+** to the comparison.  This makes the opcode work like IdxLE.
+*/
+case OP_IdxLT:          /* jump, in3 */
+case OP_IdxGE: {        /* jump, in3 */
+int i= pOp->p1;
+Cursor *pC;
+assert( i>=0 && i<p->nCursor );
+assert( p->apCsr[i]!=0 );
+if( (pC = p->apCsr[i])->pCursor!=0 ){
+int res;
+UnpackedRecord r;
+assert( pC->deferredMoveto==0 );
+assert( pOp->p5==0 || pOp->p5==1 );
+assert( pOp->p4type==P4_INT32 );
+r.pKeyInfo = pC->pKeyInfo;
+r.nField = pOp->p4.i;
+if( pOp->p5 ){
+r.flags = UNPACKED_INCRKEY | UNPACKED_IGNORE_ROWID;
+}else{
+r.flags = UNPACKED_IGNORE_ROWID;
+}
+r.aMem = &p->aMem[pOp->p3];
+rc = sqlite3VdbeIdxKeyCompare(pC, &r, &res);
+if( pOp->opcode==OP_IdxLT ){
+res = -res;
+}else{
+assert( pOp->opcode==OP_IdxGE );
+res++;
+}
+if( res>0 ){
+pc = pOp->p2 - 1 ;
+}
+}
+break;
+}
+/* Opcode: Destroy P1 P2 P3 * *
+**
+** Delete an entire database table or index whose root page in the database
+** file is given by P1.
+**
+** The table being destroyed is in the main database file if P3==0.  If
+** P3==1 then the table to be clear is in the auxiliary database file
+** that is used to store tables create using CREATE TEMPORARY TABLE.
+**
+** If AUTOVACUUM is enabled then it is possible that another root page
+** might be moved into the newly deleted root page in order to keep all
+** root pages contiguous at the beginning of the database.  The former
+** value of the root page that moved - its value before the move occurred -
+** is stored in register P2.  If no page
+** movement was required (because the table being dropped was already
+** the last one in the database) then a zero is stored in register P2.
+** If AUTOVACUUM is disabled then a zero is stored in register P2.
+**
+** See also: Clear
+*/
+case OP_Destroy: {     /* out2-prerelease */
+int iMoved;
+int iCnt;
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+Vdbe *pVdbe;
+iCnt = 0;
+for(pVdbe=db->pVdbe; pVdbe; pVdbe=pVdbe->pNext){
+if( pVdbe->magic==VDBE_MAGIC_RUN && pVdbe->inVtabMethod<2 && pVdbe->pc>=0 ){
+iCnt++;
+}
+}
+#else
+iCnt = db->activeVdbeCnt;
+#endif
+if( iCnt>1 ){
+rc = SQLITE_LOCKED;
+p->errorAction = OE_Abort;
+}else{
+int iDb = pOp->p3;
+assert( iCnt==1 );
+assert( (p->btreeMask & (1<<iDb))!=0 );
+rc = sqlite3BtreeDropTable(db->aDb[iDb].pBt, pOp->p1, &iMoved);
+MemSetTypeFlag(pOut, MEM_Int);
+pOut->u.i = iMoved;
+#ifndef SQLITE_OMIT_AUTOVACUUM
+if( rc==SQLITE_OK && iMoved!=0 ){
+sqlite3RootPageMoved(&db->aDb[iDb], iMoved, pOp->p1);
+}
+#endif
+}
+break;
+}
+/* Opcode: Clear P1 P2 *
+**
+** Delete all contents of the database table or index whose root page
+** in the database file is given by P1.  But, unlike Destroy, do not
+** remove the table or index from the database file.
+**
+** The table being clear is in the main database file if P2==0.  If
+** P2==1 then the table to be clear is in the auxiliary database file
+** that is used to store tables create using CREATE TEMPORARY TABLE.
+**
+** See also: Destroy
+*/
+case OP_Clear: {
+assert( (p->btreeMask & (1<<pOp->p2))!=0 );
+rc = sqlite3BtreeClearTable(db->aDb[pOp->p2].pBt, pOp->p1);
+break;
+}
+/* Opcode: CreateTable P1 P2 * * *
+**
+** Allocate a new table in the main database file if P1==0 or in the
+** auxiliary database file if P1==1 or in an attached database if
+** P1>1.  Write the root page number of the new table into
+** register P2
+**
+** The difference between a table and an index is this:  A table must
+** have a 4-byte integer key and can have arbitrary data.  An index
+** has an arbitrary key but no data.
+**
+** See also: CreateIndex
+*/
+/* Opcode: CreateIndex P1 P2 * * *
+**
+** Allocate a new index in the main database file if P1==0 or in the
+** auxiliary database file if P1==1 or in an attached database if
+** P1>1.  Write the root page number of the new table into
+** register P2.
+**
+** See documentation on OP_CreateTable for additional information.
+*/
+case OP_CreateIndex:            /* out2-prerelease */
+case OP_CreateTable: {          /* out2-prerelease */
+int pgno;
+int flags;
+Db *pDb;
+assert( pOp->p1>=0 && pOp->p1<db->nDb );
+assert( (p->btreeMask & (1<<pOp->p1))!=0 );
+pDb = &db->aDb[pOp->p1];
+assert( pDb->pBt!=0 );
+if( pOp->opcode==OP_CreateTable ){
+/* flags = BTREE_INTKEY; */
+flags = BTREE_LEAFDATA|BTREE_INTKEY;
+}else{
+flags = BTREE_ZERODATA;
+}
+rc = sqlite3BtreeCreateTable(pDb->pBt, &pgno, flags);
+if( rc==SQLITE_OK ){
+pOut->u.i = pgno;
+MemSetTypeFlag(pOut, MEM_Int);
+}
+break;
+}
+/* Opcode: ParseSchema P1 P2 * P4 *
+**
+** Read and parse all entries from the SQLITE_MASTER table of database P1
+** that match the WHERE clause P4.  P2 is the "force" flag.   Always do
+** the parsing if P2 is true.  If P2 is false, then this routine is a
+** no-op if the schema is not currently loaded.  In other words, if P2
+** is false, the SQLITE_MASTER table is only parsed if the rest of the
+** schema is already loaded into the symbol table.
+**
+** This opcode invokes the parser to create a new virtual machine,
+** then runs the new virtual machine.  It is thus a re-entrant opcode.
+*/
+case OP_ParseSchema: {
+char *zSql;
+int iDb = pOp->p1;
+const char *zMaster;
+InitData initData;
+assert( iDb>=0 && iDb<db->nDb );
+if( !pOp->p2 && !DbHasProperty(db, iDb, DB_SchemaLoaded) ){
+break;
+}
+zMaster = SCHEMA_TABLE(iDb);
+initData.db = db;
+initData.iDb = pOp->p1;
+initData.pzErrMsg = &p->zErrMsg;
+zSql = sqlite3MPrintf(db,
+"SELECT name, rootpage, sql FROM '%q'.%s WHERE %s",
+db->aDb[iDb].zName, zMaster, pOp->p4.z);
+if( zSql==0 ) goto no_mem;
+(void)sqlite3SafetyOff(db);
+assert( db->init.busy==0 );
+db->init.busy = 1;
+initData.rc = SQLITE_OK;
+assert( !db->mallocFailed );
+rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);
+if( rc==SQLITE_OK ) rc = initData.rc;
+sqlite3DbFree(db, zSql);
+db->init.busy = 0;
+(void)sqlite3SafetyOn(db);
+if( rc==SQLITE_NOMEM ){
+goto no_mem;
+}
+break;
+}
+#if !defined(SQLITE_OMIT_ANALYZE) && !defined(SQLITE_OMIT_PARSER)
+/* Opcode: LoadAnalysis P1 * * * *
+**
+** Read the sqlite_stat1 table for database P1 and load the content
+** of that table into the internal index hash table.  This will cause
+** the analysis to be used when preparing all subsequent queries.
+*/
+case OP_LoadAnalysis: {
+int iDb = pOp->p1;
+assert( iDb>=0 && iDb<db->nDb );
+rc = sqlite3AnalysisLoad(db, iDb);
+break;
+}
+#endif /* !defined(SQLITE_OMIT_ANALYZE) && !defined(SQLITE_OMIT_PARSER)  */
+/* Opcode: DropTable P1 * * P4 *
+**
+** Remove the internal (in-memory) data structures that describe
+** the table named P4 in database P1.  This is called after a table
+** is dropped in order to keep the internal representation of the
+** schema consistent with what is on disk.
+*/
+case OP_DropTable: {
+sqlite3UnlinkAndDeleteTable(db, pOp->p1, pOp->p4.z);
+break;
+}
+/* Opcode: DropIndex P1 * * P4 *
+**
+** Remove the internal (in-memory) data structures that describe
+** the index named P4 in database P1.  This is called after an index
+** is dropped in order to keep the internal representation of the
+** schema consistent with what is on disk.
+*/
+case OP_DropIndex: {
+sqlite3UnlinkAndDeleteIndex(db, pOp->p1, pOp->p4.z);
+break;
+}
+/* Opcode: DropTrigger P1 * * P4 *
+**
+** Remove the internal (in-memory) data structures that describe
+** the trigger named P4 in database P1.  This is called after a trigger
+** is dropped in order to keep the internal representation of the
+** schema consistent with what is on disk.
+*/
+case OP_DropTrigger: {
+sqlite3UnlinkAndDeleteTrigger(db, pOp->p1, pOp->p4.z);
+break;
+}
+#ifndef SQLITE_OMIT_INTEGRITY_CHECK
+/* Opcode: IntegrityCk P1 P2 P3 * P5
+**
+** Do an analysis of the currently open database.  Store in
+** register P1 the text of an error message describing any problems.
+** If no problems are found, store a NULL in register P1.
+**
+** The register P3 contains the maximum number of allowed errors.
+** At most reg(P3) errors will be reported.
+** In other words, the analysis stops as soon as reg(P1) errors are
+** seen.  Reg(P1) is updated with the number of errors remaining.
+**
+** The root page numbers of all tables in the database are integer
+** stored in reg(P1), reg(P1+1), reg(P1+2), ....  There are P2 tables
+** total.
+**
+** If P5 is not zero, the check is done on the auxiliary database
+** file, not the main database file.
+**
+** This opcode is used to implement the integrity_check pragma.
+*/
+case OP_IntegrityCk: {
+int nRoot;      /* Number of tables to check.  (Number of root pages.) */
+int *aRoot;     /* Array of rootpage numbers for tables to be checked */
+int j;          /* Loop counter */
+int nErr;       /* Number of errors reported */
+char *z;        /* Text of the error report */
+Mem *pnErr;     /* Register keeping track of errors remaining */
+nRoot = pOp->p2;
+assert( nRoot>0 );
+aRoot = sqlite3DbMallocRaw(db, sizeof(int)*(nRoot+1) );
+if( aRoot==0 ) goto no_mem;
+assert( pOp->p3>0 && pOp->p3<=p->nMem );
+pnErr = &p->aMem[pOp->p3];
+assert( (pnErr->flags & MEM_Int)!=0 );
+assert( (pnErr->flags & (MEM_Str|MEM_Blob))==0 );
+pIn1 = &p->aMem[pOp->p1];
+for(j=0; j<nRoot; j++){
+aRoot[j] = sqlite3VdbeIntValue(&pIn1[j]);
+}
+aRoot[j] = 0;
+assert( pOp->p5<db->nDb );
+assert( (p->btreeMask & (1<<pOp->p5))!=0 );
+z = sqlite3BtreeIntegrityCheck(db->aDb[pOp->p5].pBt, aRoot, nRoot,
+pnErr->u.i, &nErr);
+sqlite3DbFree(db, aRoot);
+pnErr->u.i -= nErr;
+sqlite3VdbeMemSetNull(pIn1);
+if( nErr==0 ){
+assert( z==0 );
+}else if( z==0 ){
+goto no_mem;
+}else{
+sqlite3VdbeMemSetStr(pIn1, z, -1, SQLITE_UTF8, sqlite3_free);
+}
+UPDATE_MAX_BLOBSIZE(pIn1);
+sqlite3VdbeChangeEncoding(pIn1, encoding);
+break;
+}
+#endif /* SQLITE_OMIT_INTEGRITY_CHECK */
+/* Opcode: FifoWrite P1 * * * *
+**
+** Write the integer from register P1 into the Fifo.
+*/
+case OP_FifoWrite: {        /* in1 */
+p->sFifo.db = db;
+if( sqlite3VdbeFifoPush(&p->sFifo, sqlite3VdbeIntValue(pIn1))==SQLITE_NOMEM ){
+goto no_mem;
+}
+break;
+}
+/* Opcode: FifoRead P1 P2 * * *
+**
+** Attempt to read a single integer from the Fifo.  Store that
+** integer in register P1.
+**
+** If the Fifo is empty jump to P2.
+*/
+case OP_FifoRead: {         /* jump */
+CHECK_FOR_INTERRUPT;
+assert( pOp->p1>0 && pOp->p1<=p->nMem );
+pOut = &p->aMem[pOp->p1];
+MemSetTypeFlag(pOut, MEM_Int);
+if( sqlite3VdbeFifoPop(&p->sFifo, &pOut->u.i)==SQLITE_DONE ){
+pc = pOp->p2 - 1;
+}
+break;
+}
+#ifndef SQLITE_OMIT_TRIGGER
+/* Opcode: ContextPush * * *
+**
+** Save the current Vdbe context such that it can be restored by a ContextPop
+** opcode. The context stores the last insert row id, the last statement change
+** count, and the current statement change count.
+*/
+case OP_ContextPush: {
+int i = p->contextStackTop++;
+Context *pContext;
+assert( i>=0 );
+/* FIX ME: This should be allocated as part of the vdbe at compile-time */
+if( i>=p->contextStackDepth ){
+p->contextStackDepth = i+1;
+p->contextStack = sqlite3DbReallocOrFree(db, p->contextStack,
+sizeof(Context)*(i+1));
+if( p->contextStack==0 ) goto no_mem;
+}
+pContext = &p->contextStack[i];
+pContext->lastRowid = db->lastRowid;
+pContext->nChange = p->nChange;
+pContext->sFifo = p->sFifo;
+sqlite3VdbeFifoInit(&p->sFifo, db);
+break;
+}
+/* Opcode: ContextPop * * *
+**
+** Restore the Vdbe context to the state it was in when contextPush was last
+** executed. The context stores the last insert row id, the last statement
+** change count, and the current statement change count.
+*/
+case OP_ContextPop: {
+Context *pContext = &p->contextStack[--p->contextStackTop];
+assert( p->contextStackTop>=0 );
+db->lastRowid = pContext->lastRowid;
+p->nChange = pContext->nChange;
+sqlite3VdbeFifoClear(&p->sFifo);
+p->sFifo = pContext->sFifo;
+break;
+}
+#endif /* #ifndef SQLITE_OMIT_TRIGGER */
+#ifndef SQLITE_OMIT_AUTOINCREMENT
+/* Opcode: MemMax P1 P2 * * *
+**
+** Set the value of register P1 to the maximum of its current value
+** and the value in register P2.
+**
+** This instruction throws an error if the memory cell is not initially
+** an integer.
+*/
+case OP_MemMax: {        /* in1, in2 */
+sqlite3VdbeMemIntegerify(pIn1);
+sqlite3VdbeMemIntegerify(pIn2);
+if( pIn1->u.i<pIn2->u.i){
+pIn1->u.i = pIn2->u.i;
+}
+break;
+}
+#endif /* SQLITE_OMIT_AUTOINCREMENT */
+/* Opcode: IfPos P1 P2 * * *
+**
+** If the value of register P1 is 1 or greater, jump to P2.
+**
+** It is illegal to use this instruction on a register that does
+** not contain an integer.  An assertion fault will result if you try.
+*/
+case OP_IfPos: {        /* jump, in1 */
+assert( pIn1->flags&MEM_Int );
+if( pIn1->u.i>0 ){
+pc = pOp->p2 - 1;
+}
+break;
+}
+/* Opcode: IfNeg P1 P2 * * *
+**
+** If the value of register P1 is less than zero, jump to P2.
+**
+** It is illegal to use this instruction on a register that does
+** not contain an integer.  An assertion fault will result if you try.
+*/
+case OP_IfNeg: {        /* jump, in1 */
+assert( pIn1->flags&MEM_Int );
+if( pIn1->u.i<0 ){
+pc = pOp->p2 - 1;
+}
+break;
+}
+/* Opcode: IfZero P1 P2 * * *
+**
+** If the value of register P1 is exactly 0, jump to P2.
+**
+** It is illegal to use this instruction on a register that does
+** not contain an integer.  An assertion fault will result if you try.
+*/
+case OP_IfZero: {        /* jump, in1 */
+assert( pIn1->flags&MEM_Int );
+if( pIn1->u.i==0 ){
+pc = pOp->p2 - 1;
+}
+break;
+}
+/* Opcode: AggStep * P2 P3 P4 P5
+**
+** Execute the step function for an aggregate.  The
+** function has P5 arguments.   P4 is a pointer to the FuncDef
+** structure that specifies the function.  Use register
+** P3 as the accumulator.
+**
+** The P5 arguments are taken from register P2 and its
+** successors.
+*/
+case OP_AggStep: {
+int n = pOp->p5;
+int i;
+Mem *pMem, *pRec;
+sqlite3_context ctx;
+sqlite3_value **apVal;
+assert( n>=0 );
+pRec = &p->aMem[pOp->p2];
+apVal = p->apArg;
+assert( apVal || n==0 );
+for(i=0; i<n; i++, pRec++){
+apVal[i] = pRec;
+storeTypeInfo(pRec, encoding);
+}
+ctx.pFunc = pOp->p4.pFunc;
+assert( pOp->p3>0 && pOp->p3<=p->nMem );
+ctx.pMem = pMem = &p->aMem[pOp->p3];
+pMem->n++;
+ctx.s.flags = MEM_Null;
+ctx.s.z = 0;
+ctx.s.zMalloc = 0;
+ctx.s.xDel = 0;
+ctx.s.db = db;
+ctx.isError = 0;
+ctx.pColl = 0;
+if( ctx.pFunc->needCollSeq ){
+assert( pOp>p->aOp );
+assert( pOp[-1].p4type==P4_COLLSEQ );
+assert( pOp[-1].opcode==OP_CollSeq );
+ctx.pColl = pOp[-1].p4.pColl;
+}
+(ctx.pFunc->xStep)(&ctx, n, apVal);
+if( ctx.isError ){
+sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3_value_text(&ctx.s));
+rc = ctx.isError;
+}
+sqlite3VdbeMemRelease(&ctx.s);
+break;
+}
+/* Opcode: AggFinal P1 P2 * P4 *
+**
+** Execute the finalizer function for an aggregate.  P1 is
+** the memory location that is the accumulator for the aggregate.
+**
+** P2 is the number of arguments that the step function takes and
+** P4 is a pointer to the FuncDef for this function.  The P2
+** argument is not used by this opcode.  It is only there to disambiguate
+** functions that can take varying numbers of arguments.  The
+** P4 argument is only needed for the degenerate case where
+** the step function was not previously called.
+*/
+case OP_AggFinal: {
+Mem *pMem;
+assert( pOp->p1>0 && pOp->p1<=p->nMem );
+pMem = &p->aMem[pOp->p1];
+assert( (pMem->flags & ~(MEM_Null|MEM_Agg))==0 );
+rc = sqlite3VdbeMemFinalize(pMem, pOp->p4.pFunc);
+if( rc==SQLITE_ERROR ){
+sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3_value_text(pMem));
+}
+sqlite3VdbeChangeEncoding(pMem, encoding);
+UPDATE_MAX_BLOBSIZE(pMem);
+if( sqlite3VdbeMemTooBig(pMem) ){
+goto too_big;
+}
+break;
+}
+#if !defined(SQLITE_OMIT_VACUUM) && !defined(SQLITE_OMIT_ATTACH)
+/* Opcode: Vacuum * * * * *
+**
+** Vacuum the entire database.  This opcode will cause other virtual
+** machines to be created and run.  It may not be called from within
+** a transaction.
+*/
+case OP_Vacuum: {
+if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
+rc = sqlite3RunVacuum(&p->zErrMsg, db);
+if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
+break;
+}
+#endif
+#if !defined(SQLITE_OMIT_AUTOVACUUM)
+/* Opcode: IncrVacuum P1 P2 * * *
+**
+** Perform a single step of the incremental vacuum procedure on
+** the P1 database. If the vacuum has finished, jump to instruction
+** P2. Otherwise, fall through to the next instruction.
+*/
+case OP_IncrVacuum: {        /* jump */
+Btree *pBt;
+assert( pOp->p1>=0 && pOp->p1<db->nDb );
+assert( (p->btreeMask & (1<<pOp->p1))!=0 );
+pBt = db->aDb[pOp->p1].pBt;
+rc = sqlite3BtreeIncrVacuum(pBt);
+if( rc==SQLITE_DONE ){
+pc = pOp->p2 - 1;
+rc = SQLITE_OK;
+}
+break;
+}
+#endif
+/* Opcode: Expire P1 * * * *
+**
+** Cause precompiled statements to become expired. An expired statement
+** fails with an error code of SQLITE_SCHEMA if it is ever executed
+** (via sqlite3_step()).
+**
+** If P1 is 0, then all SQL statements become expired. If P1 is non-zero,
+** then only the currently executing statement is affected.
+*/
+case OP_Expire: {
+if( !pOp->p1 ){
+sqlite3ExpirePreparedStatements(db);
+}else{
+p->expired = 1;
+}
+break;
+}
+#ifndef SQLITE_OMIT_SHARED_CACHE
+/* Opcode: TableLock P1 P2 P3 P4 *
+**
+** Obtain a lock on a particular table. This instruction is only used when
+** the shared-cache feature is enabled.
+**
+** If P1 is  the index of the database in sqlite3.aDb[] of the database
+** on which the lock is acquired.  A readlock is obtained if P3==0 or
+** a write lock if P3==1.
+**
+** P2 contains the root-page of the table to lock.
+**
+** P4 contains a pointer to the name of the table being locked. This is only
+** used to generate an error message if the lock cannot be obtained.
+*/
+case OP_TableLock: {
+int p1 = pOp->p1;
+u8 isWriteLock = pOp->p3;
+assert( p1>=0 && p1<db->nDb );
+assert( (p->btreeMask & (1<<p1))!=0 );
+assert( isWriteLock==0 || isWriteLock==1 );
+rc = sqlite3BtreeLockTable(db->aDb[p1].pBt, pOp->p2, isWriteLock);
+if( rc==SQLITE_LOCKED ){
+const char *z = pOp->p4.z;
+sqlite3SetString(&p->zErrMsg, db, "database table is locked: %s", z);
+}
+break;
+}
+#endif /* SQLITE_OMIT_SHARED_CACHE */
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/* Opcode: VBegin * * * P4 *
+**
+** P4 may be a pointer to an sqlite3_vtab structure. If so, call the
+** xBegin method for that table.
+**
+** Also, whether or not P4 is set, check that this is not being called from
+** within a callback to a virtual table xSync() method. If it is, set the
+** error code to SQLITE_LOCKED.
+*/
+case OP_VBegin: {
+sqlite3_vtab *pVtab = pOp->p4.pVtab;
+rc = sqlite3VtabBegin(db, pVtab);
+if( pVtab ){
+sqlite3DbFree(db, p->zErrMsg);
+p->zErrMsg = pVtab->zErrMsg;
+pVtab->zErrMsg = 0;
+}
+break;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/* Opcode: VCreate P1 * * P4 *
+**
+** P4 is the name of a virtual table in database P1. Call the xCreate method
+** for that table.
+*/
+case OP_VCreate: {
+rc = sqlite3VtabCallCreate(db, pOp->p1, pOp->p4.z, &p->zErrMsg);
+break;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/* Opcode: VDestroy P1 * * P4 *
+**
+** P4 is the name of a virtual table in database P1.  Call the xDestroy method
+** of that table.
+*/
+case OP_VDestroy: {
+p->inVtabMethod = 2;
+rc = sqlite3VtabCallDestroy(db, pOp->p1, pOp->p4.z);
+p->inVtabMethod = 0;
+break;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/* Opcode: VOpen P1 * * P4 *
+**
+** P4 is a pointer to a virtual table object, an sqlite3_vtab structure.
+** P1 is a cursor number.  This opcode opens a cursor to the virtual
+** table and stores that cursor in P1.
+*/
+case OP_VOpen: {
+Cursor *pCur = 0;
+sqlite3_vtab_cursor *pVtabCursor = 0;
+sqlite3_vtab *pVtab = pOp->p4.pVtab;
+sqlite3_module *pModule = (sqlite3_module *)pVtab->pModule;
+assert(pVtab && pModule);
+if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
+rc = pModule->xOpen(pVtab, &pVtabCursor);
+sqlite3DbFree(db, p->zErrMsg);
+p->zErrMsg = pVtab->zErrMsg;
+pVtab->zErrMsg = 0;
+if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
+if( SQLITE_OK==rc ){
+/* Initialize sqlite3_vtab_cursor base class */
+pVtabCursor->pVtab = pVtab;
+/* Initialise vdbe cursor object */
+pCur = allocateCursor(p, pOp->p1, &pOp[-1], -1, 0);
+if( pCur ){
+pCur->pVtabCursor = pVtabCursor;
+pCur->pModule = pVtabCursor->pVtab->pModule;
+}else{
+db->mallocFailed = 1;
+pModule->xClose(pVtabCursor);
+}
+}
+break;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/* Opcode: VFilter P1 P2 P3 P4 *
+**
+** P1 is a cursor opened using VOpen.  P2 is an address to jump to if
+** the filtered result set is empty.
+**
+** P4 is either NULL or a string that was generated by the xBestIndex
+** method of the module.  The interpretation of the P4 string is left
+** to the module implementation.
+**
+** This opcode invokes the xFilter method on the virtual table specified
+** by P1.  The integer query plan parameter to xFilter is stored in register
+** P3. Register P3+1 stores the argc parameter to be passed to the
+** xFilter method. Registers P3+2..P3+1+argc are the argc
+** additional parameters which are passed to
+** xFilter as argv. Register P3+2 becomes argv[0] when passed to xFilter.
+**
+** A jump is made to P2 if the result set after filtering would be empty.
+*/
+case OP_VFilter: {   /* jump */
+int nArg;
+int iQuery;
+const sqlite3_module *pModule;
+Mem *pQuery = &p->aMem[pOp->p3];
+Mem *pArgc = &pQuery[1];
+sqlite3_vtab_cursor *pVtabCursor;
+sqlite3_vtab *pVtab;
+Cursor *pCur = p->apCsr[pOp->p1];
+REGISTER_TRACE(pOp->p3, pQuery);
+assert( pCur->pVtabCursor );
+pVtabCursor = pCur->pVtabCursor;
+pVtab = pVtabCursor->pVtab;
+pModule = pVtab->pModule;
+/* Grab the index number and argc parameters */
+assert( (pQuery->flags&MEM_Int)!=0 && pArgc->flags==MEM_Int );
+nArg = pArgc->u.i;
+iQuery = pQuery->u.i;
+/* Invoke the xFilter method */
+{
+int res = 0;
+int i;
+Mem **apArg = p->apArg;
+for(i = 0; i<nArg; i++){
+apArg[i] = &pArgc[i+1];
+storeTypeInfo(apArg[i], 0);
+}
+if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
+sqlite3VtabLock(pVtab);
+p->inVtabMethod = 1;
+rc = pModule->xFilter(pVtabCursor, iQuery, pOp->p4.z, nArg, apArg);
+p->inVtabMethod = 0;
+sqlite3DbFree(db, p->zErrMsg);
+p->zErrMsg = pVtab->zErrMsg;
+pVtab->zErrMsg = 0;
+sqlite3VtabUnlock(db, pVtab);
+if( rc==SQLITE_OK ){
+res = pModule->xEof(pVtabCursor);
+}
+if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
+if( res ){
+pc = pOp->p2 - 1;
+}
+}
+pCur->nullRow = 0;
+break;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/* Opcode: VRowid P1 P2 * * *
+**
+** Store into register P2  the rowid of
+** the virtual-table that the P1 cursor is pointing to.
+*/
+case OP_VRowid: {             /* out2-prerelease */
+sqlite3_vtab *pVtab;
+const sqlite3_module *pModule;
+sqlite_int64 iRow;
+Cursor *pCur = p->apCsr[pOp->p1];
+assert( pCur->pVtabCursor );
+if( pCur->nullRow ){
+break;
+}
+pVtab = pCur->pVtabCursor->pVtab;
+pModule = pVtab->pModule;
+assert( pModule->xRowid );
+if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
+rc = pModule->xRowid(pCur->pVtabCursor, &iRow);
+sqlite3DbFree(db, p->zErrMsg);
+p->zErrMsg = pVtab->zErrMsg;
+pVtab->zErrMsg = 0;
+if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
+MemSetTypeFlag(pOut, MEM_Int);
+pOut->u.i = iRow;
+break;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/* Opcode: VColumn P1 P2 P3 * *
+**
+** Store the value of the P2-th column of
+** the row of the virtual-table that the
+** P1 cursor is pointing to into register P3.
+*/
+case OP_VColumn: {
+sqlite3_vtab *pVtab;
+const sqlite3_module *pModule;
+Mem *pDest;
+sqlite3_context sContext;
+Cursor *pCur = p->apCsr[pOp->p1];
+assert( pCur->pVtabCursor );
+assert( pOp->p3>0 && pOp->p3<=p->nMem );
+pDest = &p->aMem[pOp->p3];
+if( pCur->nullRow ){
+sqlite3VdbeMemSetNull(pDest);
+break;
+}
+pVtab = pCur->pVtabCursor->pVtab;
+pModule = pVtab->pModule;
+assert( pModule->xColumn );
+memset(&sContext, 0, sizeof(sContext));
+/* The output cell may already have a buffer allocated. Move
+** the current contents to sContext.s so in case the user-function
+** can use the already allocated buffer instead of allocating a
+** new one.
+*/
+sqlite3VdbeMemMove(&sContext.s, pDest);
+MemSetTypeFlag(&sContext.s, MEM_Null);
+if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
+rc = pModule->xColumn(pCur->pVtabCursor, &sContext, pOp->p2);
+sqlite3DbFree(db, p->zErrMsg);
+p->zErrMsg = pVtab->zErrMsg;
+pVtab->zErrMsg = 0;
+/* Copy the result of the function to the P3 register. We
+** do this regardless of whether or not an error occured to ensure any
+** dynamic allocation in sContext.s (a Mem struct) is  released.
+*/
+sqlite3VdbeChangeEncoding(&sContext.s, encoding);
+REGISTER_TRACE(pOp->p3, pDest);
+sqlite3VdbeMemMove(pDest, &sContext.s);
+UPDATE_MAX_BLOBSIZE(pDest);
+if( sqlite3SafetyOn(db) ){
+goto abort_due_to_misuse;
+}
+if( sqlite3VdbeMemTooBig(pDest) ){
+goto too_big;
+}
+break;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/* Opcode: VNext P1 P2 * * *
+**
+** Advance virtual table P1 to the next row in its result set and
+** jump to instruction P2.  Or, if the virtual table has reached
+** the end of its result set, then fall through to the next instruction.
+*/
+case OP_VNext: {   /* jump */
+sqlite3_vtab *pVtab;
+const sqlite3_module *pModule;
+int res = 0;
+Cursor *pCur = p->apCsr[pOp->p1];
+assert( pCur->pVtabCursor );
+if( pCur->nullRow ){
+break;
+}
+pVtab = pCur->pVtabCursor->pVtab;
+pModule = pVtab->pModule;
+assert( pModule->xNext );
+/* Invoke the xNext() method of the module. There is no way for the
+** underlying implementation to return an error if one occurs during
+** xNext(). Instead, if an error occurs, true is returned (indicating that
+** data is available) and the error code returned when xColumn or
+** some other method is next invoked on the save virtual table cursor.
+*/
+if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
+sqlite3VtabLock(pVtab);
+p->inVtabMethod = 1;
+rc = pModule->xNext(pCur->pVtabCursor);
+p->inVtabMethod = 0;
+sqlite3DbFree(db, p->zErrMsg);
+p->zErrMsg = pVtab->zErrMsg;
+pVtab->zErrMsg = 0;
+sqlite3VtabUnlock(db, pVtab);
+if( rc==SQLITE_OK ){
+res = pModule->xEof(pCur->pVtabCursor);
+}
+if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
+if( !res ){
+/* If there is data, jump to P2 */
+pc = pOp->p2 - 1;
+}
+break;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/* Opcode: VRename P1 * * P4 *
+**
+** P4 is a pointer to a virtual table object, an sqlite3_vtab structure.
+** This opcode invokes the corresponding xRename method. The value
+** in register P1 is passed as the zName argument to the xRename method.
+*/
+case OP_VRename: {
+sqlite3_vtab *pVtab = pOp->p4.pVtab;
+Mem *pName = &p->aMem[pOp->p1];
+assert( pVtab->pModule->xRename );
+REGISTER_TRACE(pOp->p1, pName);
+Stringify(pName, encoding);
+if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
+sqlite3VtabLock(pVtab);
+rc = pVtab->pModule->xRename(pVtab, pName->z);
+sqlite3DbFree(db, p->zErrMsg);
+p->zErrMsg = pVtab->zErrMsg;
+pVtab->zErrMsg = 0;
+sqlite3VtabUnlock(db, pVtab);
+if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
+break;
+}
+#endif
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/* Opcode: VUpdate P1 P2 P3 P4 *
+**
+** P4 is a pointer to a virtual table object, an sqlite3_vtab structure.
+** This opcode invokes the corresponding xUpdate method. P2 values
+** are contiguous memory cells starting at P3 to pass to the xUpdate
+** invocation. The value in register (P3+P2-1) corresponds to the
+** p2th element of the argv array passed to xUpdate.
+**
+** The xUpdate method will do a DELETE or an INSERT or both.
+** The argv[0] element (which corresponds to memory cell P3)
+** is the rowid of a row to delete.  If argv[0] is NULL then no
+** deletion occurs.  The argv[1] element is the rowid of the new
+** row.  This can be NULL to have the virtual table select the new
+** rowid for itself.  The subsequent elements in the array are
+** the values of columns in the new row.
+**
+** If P2==1 then no insert is performed.  argv[0] is the rowid of
+** a row to delete.
+**
+** P1 is a boolean flag. If it is set to true and the xUpdate call
+** is successful, then the value returned by sqlite3_last_insert_rowid()
+** is set to the value of the rowid for the row just inserted.
+*/
+case OP_VUpdate: {
+sqlite3_vtab *pVtab = pOp->p4.pVtab;
+sqlite3_module *pModule = (sqlite3_module *)pVtab->pModule;
+int nArg = pOp->p2;
+assert( pOp->p4type==P4_VTAB );
+if( pModule->xUpdate==0 ){
+sqlite3SetString(&p->zErrMsg, db, "read-only table");
+rc = SQLITE_ERROR;
+}else{
+int i;
+sqlite_int64 rowid;
+Mem **apArg = p->apArg;
+Mem *pX = &p->aMem[pOp->p3];
+for(i=0; i<nArg; i++){
+storeTypeInfo(pX, 0);
+apArg[i] = pX;
+pX++;
+}
+if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
+sqlite3VtabLock(pVtab);
+rc = pModule->xUpdate(pVtab, nArg, apArg, &rowid);
+sqlite3DbFree(db, p->zErrMsg);
+p->zErrMsg = pVtab->zErrMsg;
+pVtab->zErrMsg = 0;
+sqlite3VtabUnlock(db, pVtab);
+if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
+if( pOp->p1 && rc==SQLITE_OK ){
+assert( nArg>1 && apArg[0] && (apArg[0]->flags&MEM_Null) );
+db->lastRowid = rowid;
+}
+p->nChange++;
+}
+break;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+#ifndef  SQLITE_OMIT_PAGER_PRAGMAS
+/* Opcode: Pagecount P1 P2 * * *
+**
+** Write the current number of pages in database P1 to memory cell P2.
+*/
+case OP_Pagecount: {            /* out2-prerelease */
+int p1 = pOp->p1;
+int nPage;
+Pager *pPager = sqlite3BtreePager(db->aDb[p1].pBt);
+rc = sqlite3PagerPagecount(pPager, &nPage);
+if( rc==SQLITE_OK ){
+pOut->flags = MEM_Int;
+pOut->u.i = nPage;
+}
+break;
+}
+#endif
+#ifndef SQLITE_OMIT_TRACE
+/* Opcode: Trace * * * P4 *
+**
+** If tracing is enabled (by the sqlite3_trace()) interface, then
+** the UTF-8 string contained in P4 is emitted on the trace callback.
+*/
+case OP_Trace: {
+if( pOp->p4.z ){
+if( db->xTrace ){
+db->xTrace(db->pTraceArg, pOp->p4.z);
+}
+#ifdef SQLITE_DEBUG
+if( (db->flags & SQLITE_SqlTrace)!=0 ){
+sqlite3DebugPrintf("SQL-trace: %s\n", pOp->p4.z);
+}
+#endif /* SQLITE_DEBUG */
+}
+break;
+}
+#endif
+/* Opcode: Noop * * * * *
+**
+** Do nothing.  This instruction is often useful as a jump
+** destination.
+*/
+/*
+** The magic Explain opcode are only inserted when explain==2 (which
+** is to say when the EXPLAIN QUERY PLAN syntax is used.)
+** This opcode records information from the optimizer.  It is the
+** the same as a no-op.  This opcodesnever appears in a real VM program.
+*/
+default: {          /* This is really OP_Noop and OP_Explain */
+break;
+}
+/*****************************************************************************
+** The cases of the switch statement above this line should all be indented
+** by 6 spaces.  But the left-most 6 spaces have been removed to improve the
+** readability.  From this point on down, the normal indentation rules are
+** restored.
+*****************************************************************************/
+}
+#ifdef VDBE_PROFILE
+{
+u64 elapsed = sqlite3Hwtime() - start;
+pOp->cycles += elapsed;
+pOp->cnt++;
+#if 0
+fprintf(stdout, "%10llu ", elapsed);
+sqlite3VdbePrintOp(stdout, origPc, &p->aOp[origPc]);
+#endif
+}
+#endif
+/* The following code adds nothing to the actual functionality
+** of the program.  It is only here for testing and debugging.
+** On the other hand, it does burn CPU cycles every time through
+** the evaluator loop.  So we can leave it out when NDEBUG is defined.
+*/
+#ifndef NDEBUG
+assert( pc>=-1 && pc<p->nOp );
+#ifdef SQLITE_DEBUG
+if( p->trace ){
+if( rc!=0 ) fprintf(p->trace,"rc=%d\n",rc);
+if( opProperty & OPFLG_OUT2_PRERELEASE ){
+registerTrace(p->trace, pOp->p2, pOut);
+}
+if( opProperty & OPFLG_OUT3 ){
+registerTrace(p->trace, pOp->p3, pOut);
+}
+}
+#endif  /* SQLITE_DEBUG */
+#endif  /* NDEBUG */
+}  /* The end of the for(;;) loop the loops through opcodes */
+/* If we reach this point, it means that execution is finished with
+** an error of some kind.
+*/
+vdbe_error_halt:
+assert( rc );
+p->rc = rc;
+sqlite3VdbeHalt(p);
+if( rc==SQLITE_IOERR_NOMEM ) db->mallocFailed = 1;
+rc = SQLITE_ERROR;
+/* This is the only way out of this procedure.  We have to
+** release the mutexes on btrees that were acquired at the
+** top. */
+vdbe_return:
+sqlite3BtreeMutexArrayLeave(&p->aMutex);
+return rc;
+/* Jump to here if a string or blob larger than SQLITE_MAX_LENGTH
+** is encountered.
+*/
+too_big:
+sqlite3SetString(&p->zErrMsg, db, "string or blob too big");
+rc = SQLITE_TOOBIG;
+goto vdbe_error_halt;
+/* Jump to here if a malloc() fails.
+*/
+no_mem:
+db->mallocFailed = 1;
+sqlite3SetString(&p->zErrMsg, db, "out of memory");
+rc = SQLITE_NOMEM;
+goto vdbe_error_halt;
+/* Jump to here for an SQLITE_MISUSE error.
+*/
+abort_due_to_misuse:
+rc = SQLITE_MISUSE;
+/* Fall thru into abort_due_to_error */
+/* Jump to here for any other kind of fatal error.  The "rc" variable
+** should hold the error number.
+*/
+abort_due_to_error:
+assert( p->zErrMsg==0 );
+if( db->mallocFailed ) rc = SQLITE_NOMEM;
+if( rc!=SQLITE_IOERR_NOMEM ){
+sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3ErrStr(rc));
+}
+goto vdbe_error_halt;
+/* Jump to here if the sqlite3_interrupt() API sets the interrupt
+** flag.
+*/
+abort_due_to_interrupt:
+assert( db->u1.isInterrupted );
+rc = SQLITE_INTERRUPT;
+p->rc = rc;
+sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3ErrStr(rc));
+goto vdbe_error_halt;
+}