History of Microsoft SQL Server
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
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 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, 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. 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 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 was introduced to handle SQL Server threads better than Windows preemptive multi-threading, also adding support for fibers. SQL Server 7.0 also introduced a multi-dimensional database product called SQL OLAP Services.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 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. 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 tool
- SQL Server Reporting Services, or "Reporting Server"
- an OLAP and data mining server
- several messaging technologies, specifically Service Broker and Notification Services
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. 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 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 anxml 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 packets encapsulated within SOAP requests. When the data is accessed over web services, results are returned as XML.Common Language Runtime 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 and support for recursive queries with CTEs. 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 ; 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, a method of allowing usage of database connections for multiple purposes.
- DMVs, 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.
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 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, 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, 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" data type represents geospatial data which has been projected from its native, spherical, coordinate system into a plane. A "Round Earth" data type 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.
SQL Server includes better compression features, which also helps in improving scalability. It enhanced the indexing algorithms and introduced the notion of filtered indexes. It also includes Resource Governor that allows reserving resources for certain users or workflows. It also includes capabilities for transparent encryption of data as well as compression of backups. SQL Server 2008 supports the ADO.NET Entity Framework and the reporting tools, replication, and data definition will be built around the Entity Data Model. SQL Server Reporting Services will gain charting capabilities from the integration of the data visualization products from Dundas Data Visualization, Inc., which was acquired by Microsoft. On the management side, SQL Server 2008 includes the Declarative Management Framework which allows configuring policies and constraints, on the entire database or certain tables, declaratively. The version of SQL Server Management Studio included with SQL Server 2008 supports IntelliSense for SQL queries against a SQL Server 2008 Database Engine. SQL Server 2008 also makes the databases available via Windows PowerShell providers and management functionality available as Cmdlets, so that the server and all the running instances can be managed from Windows PowerShell.
The final SQL Server 2008 service pack was released on September 30, 2014.
SQL Server 2008 had mainstream support until July 8, 2014, and extended support until July 9, 2019. Volume licensed Standard, Web, Enterprise, Workgroup and Datacenter editions of SQL Server 2008 are eligible for the Extended Security Updates program. The first term of yearly installment ended on July 14, 2020, the second term ended on July 13, 2021, and the third term ended on July 12, 2022. Those volume licensed editions rehosted on Microsoft Azure automatically received ESUs until July 11, 2023.