The history of Microsoft SQL Server begins with the first

Microsoft SQL Server Microsoft SQL Server is a relational database management system developed by Microsoft. As a database server, it is a software product with the primary function of storing and retrieving data as requested by other software applications—which ...

database product – SQL Server v1.0, a 16-bit

relational database A relational database is a (most commonly digital) database based on the relational model of data, as proposed by E. F. Codd in 1970. A system used to maintain relational databases is a relational database management system (RDBMS). Many relatio ...

for the

OS/2 OS/2 (Operating System/2) is a series of computer operating systems, initially created by Microsoft and IBM under the leadership of IBM software designer Ed Iacobucci. As a result of a feud between the two companies over how to position OS/2 ...

operating system, released in 1989.

Versions

Detailed history

Genesis

On June 12, 1988, Microsoft joined Ashton-Tate was fighting for their desktop product dBASE while

Sybase Sybase, Inc. was an enterprise software and services company. The company produced software to manage and analyze information in relational databases, with facilities located in California and Massachusetts. Sybase was acquired by SAP in 2010; ...

created a variant of

Sybase SQL Server SAP ASE (Adaptive Server Enterprise), originally known as Sybase SQL Server, and also commonly known as Sybase DB or Sybase ASE, is a relational model database server developed by Sybase Corporation, which later became part of SAP AG. ASE wa ...

for IBM

(then developed jointly with Microsoft), which was released the following year. This was the first version of Microsoft SQL Server, and served as Microsoft's entry to the enterprise-level database market, competing against

Oracle An oracle is a person or agency considered to provide wise and insightful counsel or prophetic predictions, most notably including precognition of the future, inspired by deities. As such, it is a form of divination. Description The wor ...

, 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 Windows NT is a proprietary graphical operating system produced by Microsoft, the first version of which was released on July 27, 1993. It is a processor-independent, multiprocessing and multi-user operating system. The first version of Wi ...

, 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. About the time

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 SAP ASE (Adaptive Server Enterprise), originally known as Sybase SQL Server, and also commonly known as Sybase DB or Sybase ASE, is a relational model database server developed by Sybase Corporation, which later became part of SAP AG. ASE was ...

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

SQL Server 7.0 was a major rewrite (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, as 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 IA-64 (Intel Itanium architecture) is the instruction set architecture (ISA) of the Itanium family of 64-bit Intel microprocessors. The basic ISA specification originated at Hewlett-Packard (HP), and was subsequently implemented by Intel in col ...

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 -DTS-, and subsequently SQL Server Integration Services or SSIS) *

SQL Server Reporting Services SQL Server Reporting Services (SSRS) is a server-based report generating software system from Microsoft. It is part of a suite of Microsoft SQL Server services, including SSAS ( SQL Server Analysis Services) and SSIS (SQL Server Integration Service ...

(SSRS), or "Reporting Server" *an

OLAP Online analytical processing, or OLAP (), is an approach to answer multi-dimensional analytical (MDA) queries swiftly in computing. OLAP is part of the broader category of business intelligence, which also encompasses relational databases, repo ...

and data mining server (

Analysis Services Analysis ( : analyses) is the process of breaking a complex topic or substance into smaller parts in order to gain a better understanding of it. The technique has been applied in the study of mathematics and logic since before Aristotle (38 ...

) *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 Itanium ( ) is a discontinued family of 64-bit Intel microprocessors that implement the Intel Itanium architecture (formerly called IA-64). Launched in June 2001, Intel marketed the processors for enterprise servers and high-performance comp ...

IA-64 platform. (not to be confused with the

x86-64 x86-64 (also known as x64, x86_64, AMD64, and Intel 64) is a 64-bit version of the x86 instruction set, first released in 1999. It introduced two new modes of operation, 64-bit mode and compatibility mode, along with a new 4-level paging ...

platform) Only the SQL Server relational engine and SQL Agent were ported to Itanium at this time. Client tools, such as Enterprise Manager, would still need to be run from 32-bit x86 clients. 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 April 9, 2013.

SQL Server 2005

SQL Server 2005 (formerly codenamed "Yukon") released in November 2005. It included native support for managing

XML Extensible Markup Language (XML) is a markup language and file format for storing, transmitting, and reconstructing arbitrary data. It defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. ...

data, in addition to

relational data Relational may refer to: Business * Relational capital, the value inherent in a company's relationships with its customers, vendors, and other important constituencies * Relational contract, a contract whose effect is based upon a relationship of ...

. For this purpose, it defined an xml

data type In computer science and computer programming, a data type (or simply type) is a set of possible values and a set of allowed operations on it. A data type tells the compiler or interpreter how the programmer intends to use the data. Most progra ...

that could be used either as a data type in database columns or as

literal Literal may refer to: * Interpretation of legal concepts: ** Strict constructionism ** The plain meaning rule (a.k.a. "literal rule") * Literal (mathematical logic), certain logical roles taken by propositions * Literal (computer programmin ...

s in queries. XML columns can be associated with XSD schemas; XML data being stored is verified against the schema. XML is converted to an internal binary data type before being stored in the database. Specialized indexing methods were made available for XML data. XML data is queried using

XQuery XQuery (XML Query) is a query and functional programming language that queries and transforms collections of structured and unstructured data, usually in the form of XML, text and with vendor-specific extensions for other data formats (JSON, bi ...

; SQL Server 2005 added some extensions to the

T-SQL Transact-SQL (T-SQL) is Microsoft's and Sybase's proprietary extension to the SQL (Structured Query Language) used to interact with relational databases. T-SQL expands on the SQL standard to include procedural programming, local variables, vari ...

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 Tabular Data Stream (TDS) is an application layer protocol used to transfer data between a database server and a client. It was initially designed and developed by Sybase Inc. for their Sybase SQL Server relational database engine in 1984, and later ...

(TDS) packets encapsulated within

SOAP (protocol) Soap is a salt of a fatty acid used in a variety of cleansing and lubricating products. In a domestic setting, soaps are surfactants usually used for washing, bathing, and other types of housekeeping. In industrial settings, soaps are used as ...

requests. When the data is accessed over web services, results are returned as XML.

Common Language Runtime The Common Language Runtime (CLR), the virtual machine component of Microsoft .NET Framework, manages the execution of .NET programs. Just-in-time compilation converts the managed code (compiled intermediate language code) into machine instruc ...

(CLR) integration was introduced with this version, enabling one to write SQL code as Managed Code by the CLR. For relational data,

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

checksum A checksum is a small-sized block of data derived from another block of digital data for the purpose of detecting errors that may have been introduced during its transmission or storage. By themselves, checksums are often used to verify dat ...

med 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 may refer to: Science and technology Astronomy * Cluster (spacecraft), constellation of four European Space Agency spacecraft * Asteroid cluster, a small asteroid family * Cluster II (spacecraft), a European Space Agency mission to study th ...

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 Multiversion concurrency control (MCC or MVCC), is a concurrency control method commonly used by database management systems to provide concurrent access to the database and in programming languages to implement transactional memory. Description W ...

(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. SQL Server 2005 introduced "MARS" (Multiple Active Results Sets), a method of allowing usage of

database connection A database connection is a facility in computer science that allows client software to talk to database server software, whether on the same machine or not. A connection is required to send commands and receive answers, usually in the form of a res ...

s for multiple purposes.Multiple Active Result Sets (MARS) in SQL Server 2005. retrieved June 20, 2009
/ref> SQL Server 2005 introduced DMVs (Dynamic Management Views), which are specialized views and functions that return server state information that can be used to monitor the health of a server instance, diagnose probl