Codasyl

IMS was generally similar in concept to CODASYL, but used a strict hierarchy for its model of data navigation instead of CODASYL's network model.

IBM was slow to implement a relational database in an effort to protect the revenues of its CODASYL database IMS/DB.

COBOL Grace Murray Hopper at the UNIVAC keyboard, c. 1960 In the spring of 1959, a two-day conference known as the Conference on Data Systems Languages ( CODASYL ) brought together computer experts from industry and government.

Codd's ideas were establishing themselves as both workable and superior to CODASYL, pushing IBM to develop a true production version of System R, known as SQL/DS, and, later, Database 2 (DB2).

In 1971, the Database Task Group delivered their standard, which generally became known as the "CODASYL approach", and soon a number of commercial products based on this approach entered the market.

Instead of records being stored in some sort of linked list of free-form records as in CODASYL, Codd's idea was to use a " table " of fixed-length records, with each table used for a different type of entity.

Many CODASYL databases also added a very straightforward query language.