DBMS -Overview

DBMS -OverviewProvides an interface to relational databases. -

Purpose

The -DBMS component provides an interface to relational databases. It enables you -to create and access databases either from a single client or from multiple -clients sharing access over a server.

Required background

To use DBMS you need a knowledge -of relational databases and the SQL query language.

Key concepts and terms

Store database: A client-side single client database stored in permanent file stores, -implemented by RDbStoreDatabase
Named database: A database allowing simultaneous read/write access by multiple clients, -implemented by RDbNamedDatabase

Architecture

DBMS defines a general relational -database access API, and allows different database implementations to be provided -of which there are two: a small and relatively lightweight client-side implementation; -and, for when multiple clients must have write access to a database, a client-server -implementation.

When multiple clients can access the same database, -transactions ensure that only one client can change data at a time.

The File Stores API defines -a sophisticated file storage, called permanent file stores, that allows individual -entries in a file to be modified. The database implementations use these stores -for the underlying data storage.

- DBMS Class Diagrams - -

DBMS Summary

DBMS provides the following:

Database Management -System Library

edbms.dll
Database Management -System Server

edbsrv.exe

APIs - - - -API -Description - - - - -

RDbDatabase

Abstract database class.

- - -

RDbStoreDatabase

Implements RDbDatabase as a store database.

- - -

RDbNamedDatabase

Implements a named database.

- - -

RDbRowSet

The base class for all rowset types.

- - -

RDbTable

Provides access to table data as a rowset.

- - -

RDbView

Generates rowsets from an SQL query.

- - -

TDbQuery

A wrapper for an SQL string combined with a text comparison mode.

- - -

TDbWindow

Describes the desired shape of a view's pre-evaluation window.

- - -

RDbNotifier

Provides notification of database changes to clients.

- - - -

Typical uses

DBMS is very well suited to applications -with small to medium-sized datasets, where the total record count is less -than 10,000 and the database size is less than 512KB. It scales reasonably -well to larger datasets with total record counts less than 100,000 and database -sizes less than 10MB.

DBMS is a suitable database engine for applications -such as:

address books
call logs
message stores.

-Persistent -Storage Overview -DBMS -rowsets overview -DBMS columns, -column sets, and keys overview -DBMS sharing -databases overview -DBMS incremental -operations overview -File stores -overview + + + + + +DBMS +OverviewProvides an interface to relational databases. +

Purpose

The +DBMS component provides an interface to relational databases. It enables you +to create and access databases either from a single client or from multiple +clients sharing access over a server.

Required background

To use DBMS you need a knowledge +of relational databases and the SQL query language.

Key concepts and terms

Store database: A client-side single client database stored in permanent file stores, +implemented by RDbStoreDatabase
Named database: A database allowing simultaneous read/write access by multiple clients, +implemented by RDbNamedDatabase

Architecture

DBMS defines a general relational +database access API, and allows different database implementations to be provided +of which there are two: a small and relatively lightweight client-side implementation; +and, for when multiple clients must have write access to a database, a client-server +implementation.

When multiple clients can access the same database, +transactions ensure that only one client can change data at a time.

The File Stores API defines +a sophisticated file storage, called permanent file stores, that allows individual +entries in a file to be modified. The database implementations use these stores +for the underlying data storage.

+ DBMS Class Diagrams + +

DBMS Summary

DBMS provides the following:

Database Management +System Library

edbms.dll
Database Management +System Server

edbsrv.exe

APIs + + + +API +Description + + + + +

RDbDatabase

Abstract database class.

+ + +

RDbStoreDatabase

Implements RDbDatabase as a store database.

+ + +

RDbNamedDatabase

Implements a named database.

+ + +

RDbRowSet

The base class for all rowset types.

+ + +

RDbTable

Provides access to table data as a rowset.

+ + +

RDbView

Generates rowsets from an SQL query.

+ + +

TDbQuery

A wrapper for an SQL string combined with a text comparison mode.

+ + +

TDbWindow

Describes the desired shape of a view's pre-evaluation window.

+ + +

RDbNotifier

Provides notification of database changes to clients.

+ + + +

Typical uses

DBMS is very well suited to applications +with small to medium-sized datasets, where the total record count is less +than 10,000 and the database size is less than 512KB. It scales reasonably +well to larger datasets with total record counts less than 100,000 and database +sizes less than 10MB.

DBMS is a suitable database engine for applications +such as:

address books
call logs
message stores.

+Persistent +Storage Overview +DBMS +rowsets overview +DBMS columns, +column sets, and keys overview +DBMS sharing +databases overview +DBMS incremental +operations overview +File stores +overview

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