Microsoft Access

Microsoft Access
Microsoft Office Access 2024 running on Windows 11
Developer	Microsoft
Release	November 16, 1992;33 years ago (1992-11-16)

Microsoft Access is a database management system (DBMS) from Microsoft that combines the relational Access Database Engine (ACE) with a graphical user interface and software-development tools. It is part of the Microsoft 365 suite of applications, included in the Professional and higher editions or sold separately.

Microsoft Access stores data in its own format based on the Access Database Engine (formerly Jet Database Engine). It can also import or link directly to data stored in other applications and databases.

Software developers, data architects and power users can use Microsoft Access to develop application software. Like other Microsoft Office applications, Access is supported by Visual Basic for Applications (VBA), an object-based programming language that can reference a variety of objects including the legacy DAO (Data Access Objects), ActiveX Data Objects, and many other ActiveX components. Visual objects used in forms and reports expose their methods and properties in the VBA programming environment, and VBA code modules may declare and call Windows operating system operations.

In July 2011, Microsoft acknowledged an intermittent query performance problem with all versions of Access and Windows 7 and Windows Server 2008 R2 due to the nature of resource management being vastly different in newer operating systems. This issue severely affects query performance on both Access 2003 and earlier with the Jet Database Engine code, as well as Access 2007 and later with the Access Database Engine (ACE). Microsoft has issued hotfixes KB2553029 for Access 2007 and KB2553116 for Access 2010, but will not fix the issue with Jet 4.0 as it is out of mainstream support.

In earlier versions of Microsoft Access, the ability to distribute applications required the purchase of the Developer Toolkit; in Access 2007, 2010 and Access 2013 the "Runtime Only" version is offered as a free download, making the distribution of royalty-free applications possible on Windows XP, Vista, 7 and Windows 8.x.

Microsoft Access applications can adopt a split-database architecture. The single database can be divided into a separate "back-end" file that contains the data tables (shared on a file server) and a "front-end" (containing the application's objects such as queries, forms, reports, macros, and modules). The "front-end" Access application is distributed to each user's desktop and linked to the shared database. Using this approach, each user has a copy of Microsoft Access (or the runtime version) installed on their machine along with their application database. This reduces network traffic since the application is not retrieved for each use. The "front-end" database can still contain local tables for storing a user's settings or temporary data. This split-database design also allows development of the application independent of the data. One disadvantage is that users may make various changes to their own local copy of the application and this makes it hard to manage version control. When a new version is ready, the front-end database is replaced without impacting the data database. Microsoft Access has two built-in utilities, Database Splitter and Linked Table Manager, to facilitate this architecture.

Linked tables in Access use absolute paths rather than relative paths, so the development environment either has to have the same path as the production environment or a "dynamic-linker" routine can be written in VBA.

For very large Access databases, this may have performance issues and a SQL backend should be considered in these circumstances. This is less of an issue if the entire database can fit in the PC's RAM since Access caches data and indexes.

Left: The icon for .mdb files.
Right: The icon for .accdb files. The file formats are differentiated by using the Access logo as seen in Office 2000 and the logo for the current version of Access.

Microsoft Access saves information under the following file formats:

There are no Access versions between 2.0 and 7.0 because the Office 95 version was launched with Word 7. All of the Office 95 products have OLE 2 capabilities, and Access 7 shows that it was compatible with Word 7.

Version number 13 was skipped.

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