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The History of SQL

The Problem

In the 60's database software required the use of complex mainframe machines that were difficult to maintain and run. Information technologists worked around the clock monitoring, updated, and manually uncorrupting these machines.

Each mainframe ran different software from different manufacturers. IBM pulled ahead in software development internationally with efforts of software aimed at database management. The problem was that each mainframe ran a different type of "language"

Software at the time was still underdeveloped and several continuous problems plagued database storage. Transactions happening at the same time were often combined, mixed together, or even lost altogether. For instance, say two individuals place make a deposit at exactly the same time from two different locations, often times the software was unable to cope with this and their bank transactions could be completely switched. Suzy deposited $10,000 while Joe withdrew $15. Because of the faulty software it was not uncommon to see Joe's withdrawal post on Suzy's account while Suzy's deposit is posted on Joe's account.

Edgar Frank "Ted" Codd

Edgar Frank “Ted” Codd (August 23, 1923- April 18, 2003) was a British mathematician and computer scientist, considered by many to be the father of the modern relational database management system.

He began as a pilot in the Royal Air Force during World War II, he began his career in New York as a mathematical programmer. He subsequently relocated to Canada only to return to the United States in the 1960's where he embarked on his doctorate at the University of Michigan, Ann Arbor, sponsored by an IBM scholarship.

Having completed his Ph.D. in computer science in 1967, he continued his career with IBM at the Almaden Research Center in San Jose, California. It was here where he began to ponder the question of how to better manage data in existing computer systems.

In June of 1970, he proposed his landmark paper pivotally defining a relational database management system entitled "A Relational Model of Data for Large Shared Data Banks"

Codd continued to publish papers expanding upon this relational concept of data, thereby laying the theoretical foundations of modern database design. His ideas shaped and revolutionized how computers and information systems store and process data into the 21rst century. His long time IBM colleague, Chris Date remarked,

"Codd's biggest overall achievement was to make database management into a science. He put the field on a solid scientific footing by providing a theoretical framework - the relational model - within which a variety of important problems could be attacked in a scientific manner."

The Answer

The publication of Codd's rules resulted in a considerable amount of relational database research done in the early 1970s. By 1974, IBM had surfaced with a prototype of a relational database called System/R. The System/R project ended in 1979, but two significant accomplishments are accredited to that project. The relational data model's viability was sufficiently proven to the world and the project included significant work on a database query language. 

By the end of the System/R project, IBM had implemented a language that supported System/R's multi-table queries and multiple-user access called the Structured English Query Language (SEQUEL). The name later was shortened to Structured Query Language (SQL). Today, we still pronounce the abbreviation as "sequel" because of these early roots.

A group of engineers watching the System/R project realized relational databases' potential and formed a company named Relational Software, Inc. In 1979, they produced the first commercially available relational database management system and implemented SQL as its query language. They called the product Oracle.

As a language, SQL did have its competitors, most notable was QUEL, used by the Ingres RDBMS. During the early 1980's, Oracle and Ingres's provider, Relational Technology, Inc., slugged it out on the commercial market before Ingres lost in 1986 and adopted SQL as its query language. Of course, IBM followed up its System/R research project with its own product, SQL/Data System (SQL/DS) and later Database 2 (DB2). With IBM's weight behind the product, their version of SQL became the de facto standard.

Relational Database Management Systems (RDBMS)

Along came Relational Database Management Systems (RDBMS). This software is still being used and is quite powerful. Relational databases allow the developer to build relationships between databases and tables. This provides tremendous opportunities for data management and is still the favorite software used today. MySQL, SQL Server, DB2, and Oracle are all RDBMSs and each have a substantial hold in the market share to this day.

Since then, many relational database management systems have come to market, all supporting SQL as their primary language. Once it became apparent that relational databases were here to stay, ANSI began work on creating a standard definition. Today's SQL standard is based mostly on IBM's implementation, with a considerable amount of additions. In fact, the SQL2 standard contains definitions of features that have yet to be implemented by any of the major vendors.

Is there only one SQL Standard?

No, A second standard for SQL sprung up in Europe from X/OPEN, a group assembling standards for a UNIX-based portable application environment. X/OPEN standards play a major role in the European market; unfortunately, several features differ between the X/OPEN and the ANSI/ISO standards. The major commercial databases all adhere to the ANSI/ISO standard, including Microsoft SQL Server 7, Oracle 8, Informix, Sybase, and, of course, IBM DB2.