|
1 /* |
|
2 ** 2007 May 7 |
|
3 ** |
|
4 ** The author disclaims copyright to this source code. In place of |
|
5 ** a legal notice, here is a blessing: |
|
6 ** |
|
7 ** May you do good and not evil. |
|
8 ** May you find forgiveness for yourself and forgive others. |
|
9 ** May you share freely, never taking more than you give. |
|
10 ** |
|
11 ************************************************************************* |
|
12 ** |
|
13 ** This file defines various limits of what SQLite can process. |
|
14 ** |
|
15 ** @(#) $Id: sqliteLimit.h 1282 2008-11-13 09:31:33Z LarsPson $ |
|
16 */ |
|
17 |
|
18 /* |
|
19 ** The maximum length of a TEXT or BLOB in bytes. This also |
|
20 ** limits the size of a row in a table or index. |
|
21 ** |
|
22 ** The hard limit is the ability of a 32-bit signed integer |
|
23 ** to count the size: 2^31-1 or 2147483647. |
|
24 */ |
|
25 #ifndef SQLITE_MAX_LENGTH |
|
26 # define SQLITE_MAX_LENGTH 1000000000 |
|
27 #endif |
|
28 |
|
29 /* |
|
30 ** This is the maximum number of |
|
31 ** |
|
32 ** * Columns in a table |
|
33 ** * Columns in an index |
|
34 ** * Columns in a view |
|
35 ** * Terms in the SET clause of an UPDATE statement |
|
36 ** * Terms in the result set of a SELECT statement |
|
37 ** * Terms in the GROUP BY or ORDER BY clauses of a SELECT statement. |
|
38 ** * Terms in the VALUES clause of an INSERT statement |
|
39 ** |
|
40 ** The hard upper limit here is 32676. Most database people will |
|
41 ** tell you that in a well-normalized database, you usually should |
|
42 ** not have more than a dozen or so columns in any table. And if |
|
43 ** that is the case, there is no point in having more than a few |
|
44 ** dozen values in any of the other situations described above. |
|
45 */ |
|
46 #ifndef SQLITE_MAX_COLUMN |
|
47 # define SQLITE_MAX_COLUMN 2000 |
|
48 #endif |
|
49 |
|
50 /* |
|
51 ** The maximum length of a single SQL statement in bytes. |
|
52 ** The hard limit is 1 million. |
|
53 */ |
|
54 #ifndef SQLITE_MAX_SQL_LENGTH |
|
55 # define SQLITE_MAX_SQL_LENGTH 1000000 |
|
56 #endif |
|
57 |
|
58 /* |
|
59 ** The maximum depth of an expression tree. This is limited to |
|
60 ** some extent by SQLITE_MAX_SQL_LENGTH. But sometime you might |
|
61 ** want to place more severe limits on the complexity of an |
|
62 ** expression. A value of 0 (the default) means do not enforce |
|
63 ** any limitation on expression tree depth. |
|
64 */ |
|
65 #ifndef SQLITE_MAX_EXPR_DEPTH |
|
66 # define SQLITE_MAX_EXPR_DEPTH 1000 |
|
67 #endif |
|
68 |
|
69 /* |
|
70 ** The maximum number of terms in a compound SELECT statement. |
|
71 ** The code generator for compound SELECT statements does one |
|
72 ** level of recursion for each term. A stack overflow can result |
|
73 ** if the number of terms is too large. In practice, most SQL |
|
74 ** never has more than 3 or 4 terms. Use a value of 0 to disable |
|
75 ** any limit on the number of terms in a compount SELECT. |
|
76 */ |
|
77 #ifndef SQLITE_MAX_COMPOUND_SELECT |
|
78 # define SQLITE_MAX_COMPOUND_SELECT 500 |
|
79 #endif |
|
80 |
|
81 /* |
|
82 ** The maximum number of opcodes in a VDBE program. |
|
83 ** Not currently enforced. |
|
84 */ |
|
85 #ifndef SQLITE_MAX_VDBE_OP |
|
86 # define SQLITE_MAX_VDBE_OP 25000 |
|
87 #endif |
|
88 |
|
89 /* |
|
90 ** The maximum number of arguments to an SQL function. |
|
91 */ |
|
92 #ifndef SQLITE_MAX_FUNCTION_ARG |
|
93 # define SQLITE_MAX_FUNCTION_ARG 100 |
|
94 #endif |
|
95 |
|
96 /* |
|
97 ** The maximum number of in-memory pages to use for the main database |
|
98 ** table and for temporary tables. The SQLITE_DEFAULT_CACHE_SIZE |
|
99 */ |
|
100 #ifndef SQLITE_DEFAULT_CACHE_SIZE |
|
101 # define SQLITE_DEFAULT_CACHE_SIZE 2000 |
|
102 #endif |
|
103 #ifndef SQLITE_DEFAULT_TEMP_CACHE_SIZE |
|
104 # define SQLITE_DEFAULT_TEMP_CACHE_SIZE 500 |
|
105 #endif |
|
106 |
|
107 /* |
|
108 ** The maximum number of attached databases. This must be at least 2 |
|
109 ** in order to support the main database file (0) and the file used to |
|
110 ** hold temporary tables (1). And it must be less than 32 because |
|
111 ** we use a bitmask of databases with a u32 in places (for example |
|
112 ** the Parse.cookieMask field). |
|
113 */ |
|
114 #ifndef SQLITE_MAX_ATTACHED |
|
115 # define SQLITE_MAX_ATTACHED 10 |
|
116 #endif |
|
117 |
|
118 |
|
119 /* |
|
120 ** The maximum value of a ?nnn wildcard that the parser will accept. |
|
121 */ |
|
122 #ifndef SQLITE_MAX_VARIABLE_NUMBER |
|
123 # define SQLITE_MAX_VARIABLE_NUMBER 999 |
|
124 #endif |
|
125 |
|
126 /* Maximum page size. The upper bound on this value is 32768. This a limit |
|
127 ** imposed by the necessity of storing the value in a 2-byte unsigned integer |
|
128 ** and the fact that the page size must be a power of 2. |
|
129 */ |
|
130 #ifndef SQLITE_MAX_PAGE_SIZE |
|
131 # define SQLITE_MAX_PAGE_SIZE 32768 |
|
132 #endif |
|
133 |
|
134 |
|
135 /* |
|
136 ** The default size of a database page. |
|
137 */ |
|
138 #ifndef SQLITE_DEFAULT_PAGE_SIZE |
|
139 # define SQLITE_DEFAULT_PAGE_SIZE 1024 |
|
140 #endif |
|
141 #if SQLITE_DEFAULT_PAGE_SIZE>SQLITE_MAX_PAGE_SIZE |
|
142 # undef SQLITE_DEFAULT_PAGE_SIZE |
|
143 # define SQLITE_DEFAULT_PAGE_SIZE SQLITE_MAX_PAGE_SIZE |
|
144 #endif |
|
145 |
|
146 /* |
|
147 ** Ordinarily, if no value is explicitly provided, SQLite creates databases |
|
148 ** with page size SQLITE_DEFAULT_PAGE_SIZE. However, based on certain |
|
149 ** device characteristics (sector-size and atomic write() support), |
|
150 ** SQLite may choose a larger value. This constant is the maximum value |
|
151 ** SQLite will choose on its own. |
|
152 */ |
|
153 #ifndef SQLITE_MAX_DEFAULT_PAGE_SIZE |
|
154 # define SQLITE_MAX_DEFAULT_PAGE_SIZE 8192 |
|
155 #endif |
|
156 #if SQLITE_MAX_DEFAULT_PAGE_SIZE>SQLITE_MAX_PAGE_SIZE |
|
157 # undef SQLITE_MAX_DEFAULT_PAGE_SIZE |
|
158 # define SQLITE_MAX_DEFAULT_PAGE_SIZE SQLITE_MAX_PAGE_SIZE |
|
159 #endif |
|
160 |
|
161 |
|
162 /* |
|
163 ** Maximum number of pages in one database file. |
|
164 ** |
|
165 ** This is really just the default value for the max_page_count pragma. |
|
166 ** This value can be lowered (or raised) at run-time using that the |
|
167 ** max_page_count macro. |
|
168 */ |
|
169 #ifndef SQLITE_MAX_PAGE_COUNT |
|
170 # define SQLITE_MAX_PAGE_COUNT 1073741823 |
|
171 #endif |
|
172 |
|
173 /* |
|
174 ** Maximum length (in bytes) of the pattern in a LIKE or GLOB |
|
175 ** operator. |
|
176 */ |
|
177 #ifndef SQLITE_MAX_LIKE_PATTERN_LENGTH |
|
178 # define SQLITE_MAX_LIKE_PATTERN_LENGTH 50000 |
|
179 #endif |