The history of Microsoft SQL Server begins with the first Microsoft SQL Server database product – SQL Server v1.0, a 16-bit relational database for the OS/2 operating system, released in 1989.
Versions
VersionReleaseDateMainstreamEnd DateExtendedEnd DateRelease nameCode nameInternaldatabase version1.0 (OS/2)1989SQL Server 1.0 (16-bit)Filipi1.1 (OS/2)1990SQL Server 1.1 (16-bit)Pietro4.2A (OS/2)1992SQL Server 4.2A4.2B (OS/2)1993SQL Server 4.2B (16-bit)4.21a (WinNT)1993SQL Server 1aSQLNT6.01995SQL Server 6.0SQL954066.51996SQL Server 6.5Hydra4087.01998SQL Server 7.0Sphinx5151999SQL Server 7.0 OLAP ToolsPlato8.02000SQL Server 2000Shiloh5398.02003SQL Server 2000 64-bit EditionLiberty5399.0January 14, 2006SQL Server 2005Yukon611/61210.0November 6, 2008SQL Server 2008Katmai65510.252010Azure SQL database (initial release)Cloud database or CloudDB10.50July 20, 2010SQL Server 2008 R2Kilimanjaro (aka KJ)66111.0May 20, 2012SQL Server 2012Denali70612.02014Azure SQL database12.0June 5, 2014SQL Server 2014Hekaton78213.0June 1, 2016SQL Server 2016SQL1685214.0September 29, 2017SQL Server 2017Helsinki86915.0November 4, 2019SQL Server 2019Seattle89516.0November 16, 2022SQL Server 2022Dallas95717.0November 18, 2025SQL Server 2025998Legend:
Detailed history Genesis By the late 1980s Microsoft was interested in the low end of the database software market, while Sybase focused on the Fortune 1000. After the former discussed a partnership with Sybase rival Informix Corporation, in January 1988 Microsoft joined Ashton-Tate and Sybase to create a variant of Sybase SQL Server for IBM OS/2 (then developed jointly with Microsoft) compatible with Ashton-Tate's dBASE software. Information Builders, Borland, and Symantec Corporation announced support for the product. Microsoft's Bill Gates praised Sybase as the best SQL database engine, and persuaded Ashton-Tate to use it instead of its own. Rivals such as Microrim (R:Base), Novell, Oracle Corporation, and Lotus Development said that they would use their own technology, or that they expected IBM's own SQL technology in OS/2 Extended Edition to be the standard.
Scheduled for the second half of 1988, it was released in 1989. This was the first version of Microsoft SQL Server, and served as Microsoft's entry to the enterprise-level database market, competing against Oracle, IBM, Informix, Ingres and later, Sybase. SQL Server 4.2 was shipped in 1992, bundled with OS/2 version 1.3, followed by version 4.21 for Windows NT, released alongside Windows NT 3.1. SQL Server 6.0 was the first version designed for NT, and did not include any direction from Sybase.
Sybase revenue grew quickly during the late 1980s from the Microsoft relationship. About the time Windows NT was released in July 1993, Sybase and Microsoft parted ways and each pursued its own design and marketing schemes. Microsoft negotiated exclusive rights to all versions of SQL Server written for Microsoft operating systems. (In 1996 Sybase changed the name of its product to Adaptive Server Enterprise to avoid confusion with Microsoft SQL Server.) Until 1994, Microsoft's SQL Server carried three Sybase copyright notices as an indication of its origin.
SQL Server 7.0
After problems at its main rivals, SQL Server became Oracle's most important competitor. SQL Server 7.0 was a major rewrite (using C++) of the older Sybase engine, which was coded in C. Data pages were enlarged from 2k bytes to 8k bytes. Extents thereby grew from 16k bytes to 64k bytes. User Mode Scheduling (UMS) was introduced to handle SQL Server threads better than Windows preemptive multi-threading, also adding support for fibers (lightweight threads, introduced in NT 4.0, which are used to avoid context switching). SQL Server 7.0 also introduced a multi-dimensional database product called SQL OLAP Services (which became Analysis Services in SQL Server 2000). SQL Server 7.0 would be the last version to run on the DEC Alpha platform. Although there were pre-release versions of SQL 2000 (as well as Windows 2000) compiled for Alpha, these were canceled and were never commercially released. Mainstream support ended on December 31, 2005, and extended support ended on January 11, 2011.
SQL Server 2000 SQL Server 2000 included more modifications and extensions to the Sybase code base, adding support for the IA-64 architecture (now out of "mainstream" support). By SQL Server 2005 the legacy Sybase code had been completely rewritten.
Since the release of SQL Server 2000, advances have been made in performance, the client IDE tools, and several complementary systems that are packaged with SQL Server 2005. These include:
an extract-transform-load (ETL) tool (initially called Data Transformation Services or DTS, and later called SQL Server Integration Services, or SSIS) SQL Server Reporting Services (SSRS), or "Reporting Server" an OLAP and data mining server (Analysis Services) several messaging technologies, specifically Service Broker and Notification Services
SQL Server 2000 also introduced many T-SQL language enhancements, such as table variables, user-defined functions, indexed views, INSTEAD OF triggers, cascading referential constraints and some basic XML support.
With the release of Service Pack 3, Microsoft also released the first 64-bit version of the SQL Server for the Itanium IA-64 platform (not to be confused with the x86-64 platform). Only the SQL Server relational engine and SQL Agent were ported to Itanium at this time. Client tools, such as SQL Server Management Studio, were still 32-bit x86 programs. The first release of SQL IA-64 was version 8.00.760, with a build date of February 6, 2003.
Mainstream support ended on April 8, 2008, and extended support ended on April 9, 2013.
SQL Server 2005 SQL Server 2005 (formerly codenamed "Yukon") was released in November 2005, introducing native support for x64 systems and updates to Reporting Services, Analysis Services & Integration Services. It included native support for managing XML data, in addition to relational data. For this purpose, it defined an xml data type that could be used either as a data type in database columns or as literals in queries. XML columns can be associated with XSD schemas; XML data being stored is verified against the schema. XML data is queried using XQuery; SQL Server 2005 added some extensions to the T-SQL language to allow embedding XQuery queries in T-SQL. It also defines a new extension to XQuery, called XML DML, that allows query-based modifications to XML data. SQL Server 2005 also allows a database server to be exposed over web services using Tabular Data Stream (TDS) packets encapsulated within SOAP requests. When the data is accessed over web services, results are returned as XML.
Common Language Runtime (CLR) integration was introduced with this version, enabling one to write SQL code as Managed Code by the CLR. For relational data, T-SQL has been augmented with error handling features (try/catch) and support for recursive queries with CTEs (Common Table Expressions). SQL Server 2005 has also been enhanced with new indexing algorithms, syntax and better error recovery systems. Data pages are checksummed for better error resiliency, and optimistic concurrency support has been added for better performance. Permissions and access control have been made more granular and the query processor handles concurrent execution of queries in a more efficient way. Partitions on tables and indexes are supported natively, so scaling out a database onto a cluster is easier. SQL CLR was introduced with SQL Server 2005 to let it integrate with the .NET Framework.
SQL Server 2005 introduced:
Multi-Version Concurrency Control (MVCC); user facing features include new transaction isolation level called SNAPSHOT and a variation of the READ COMMITTED isolation level based on statement-level data snapshots. Multiple Active Results Sets (MARS), a method of allowing usage of database connections for multiple purposes.Multiple Active Result Sets (MARS) in SQL Server 2005. retrieved June 20, 2009 DMVs (Dynamic Management Views), specialized views and functions that return server state information that can be used to monitor the health of a server instance, diagnose problems, and tune performance.Dynamic Management Views and Functions. retrieved June 6, 2010
Service Pack 1 (SP1) was released on April 18, 2006, adding Database Mirroring, a high availability option that provides redundancy and failover capabilities at the database level (Database Mirroring was included in the RTM release of SQL Server 2005, but it was not enabled by default, being supported for evaluation purposes). Failover can be manual or automatic; automatic failover requires a witness partner and an operating mode of synchronous (also known as high-safety or full safety). Service Pack 2 released on February 19, 2007, Service Pack 3 was released on December 15, 2008, and SQL Server 2005 Service Pack 4 released on December 13, 2010.
Mainstream support for SQL Server 2005 ended on April 12, 2011, and Extended support for SQL Server 2005 ended on April 12, 2016.
SQL Server 2008 SQL Server 2008 (formerly codenamed "Katmai") was released on August 6, 2008, announced to the SQL Server Special Interest Group at the ESRI 2008 User's Conference on August 6, 2008, by Ed Katibah (Spatial Program Manager at Microsoft), and aims to make data management self-tuning, self organizing, and self maintaining with the development of SQL Server Always On technologies, to provide near-zero downtime. SQL Server 2008 also includes support for structured and semi-structured data, including digital media formats for pictures, audio, video and other multimedia data. In current versions, such multimedia data can be stored as BLOBs (binary large objects), but they are generic bitstreams. Intrinsic awareness of multimedia data will allow specialized functions to be performed on them. According to Paul Flessner, senior Vice President of Server Applications at Microsoft, SQL Server 2008 can be a data storage backend for different varieties of data: XML, email, time/calendar, file, document, spatial, etc. as well as perform search, query, analysis, sharing, and synchronization across all data types.
Other new data types include specialized date and time types and a Spatial data type for location-dependent data. Better support for unstructured and semi-structured data is provided using the new FILESTREAM data type, which can be used to reference any file stored on the file system. Structured data and metadata about the file is stored in SQL Server database, whereas the unstructured component is stored in the file system. Such files can be accessed both via Win32 file handling APIs as well as via SQL Server using T-SQL; doing the latter accesses the file data as a BLOB. Backing up and restoring the database backs up or restores the referenced files as well. SQL Server 2008 also natively supports hierarchical data, and includes T-SQL constructs to directly deal with them, without using recursive queries.
The full-text search functionality has been integrated with the database engine. According to a Microsoft technical article, this simplifies management and improves performance.
Spatial data will be stored in two types. A "Flat Earth" (GEOMETRY or planar) data type represents geospatial data which has been projected from its native, spherical, coordinate system into a plane. A "Round Earth" data type (GEOGRAPHY) uses an ellipsoidal model in which the Earth is defined as a single continuous entity which does not suffer from the singularities such as the international dateline, poles, or map projection zone "edges". Approximately 70 methods are available to represent spatial operations for the Open Geospatial Consortium Simple Features for SQL, Version 1.1.