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The Microsoft Jet Database Engine is a database engine on which several Microsoft products have been built. A database engine is the underlying component of a database, a collection of information stored on a computer in a systematic way. The first version of Jet was developed in 1992, consisting of three modules which could be used to manipulate a database. Database connect for Microsoft JET stands for ''Joint Engine Technology'', sometimes being referred to as ''Microsoft JET Engine'' or simply ''Jet''. Microsoft Access and Visual Basic use or have used Jet as their underlying database engine. It has since been superseded for general use, however, first by Microsoft Desktop Engine (MSDE), then later by SQL Server Express. For larger database needs, Jet databases can be upgraded (or, in Microsoft parlance, "up-sized") to Microsoft's flagship database product, SQL Server. However, this does not mean that a MS Jet (Red) database cannot match MS SQL Server in storage capacity. A 5 billion record MS Jet (Red) database with compression and encryption turned on requires about 1 terabyte of disk storage space, comprising hundreds of ( *.mdb) files, each acting as partial table, and not as a database in itself. Over the years, ''Jet'' has become almost synonymous with Microsoft Access, to the extent that many people refer to a Jet database as an "Access database". ==Architecture== Jet, being part of a relational database management system (RDBMS), allows the manipulation of a relational databases. It offers a single interface that other software can use to access Microsoft databases and provides support for security, referential integrity, transaction processing, indexing, record and page locking, and data replication. In later versions, the engine has been extended to run SQL queries, store character data in Unicode format, create database views and allow bi-directional replication with Microsoft SQL Server. There are three modules to Jet: One is the ''Native Jet ISAM Driver'', a dynamic link library (DLL) that can directly manipulate Microsoft Access database files (MDB) using Indexed Sequential Access Method (ISAM). Another one of the modules contains the ''ISAM Drivers'', DLLs that allow access to a variety of ISAM databases, among them xBase, Paradox, Btrieve and FoxPro, depending on the version of Jet. The final module is the ''Data Access Objects'' (DAO) DLL. DAO provides an API that allows programmers to access JET databases using any programming language. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Microsoft Jet Database Engine」の詳細全文を読む スポンサード リンク
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