The Multics Relational Data Store, or MRDS for short, was the first commercial

relational database management system 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 ...

. It was written in PL/1 by

Honeywell Honeywell International Inc. is an American publicly traded, multinational conglomerate corporation headquartered in Charlotte, North Carolina. It primarily operates in four areas of business: aerospace, building technologies, performance ma ...

for the

Multics Multics ("Multiplexed Information and Computing Service") is an influential early time-sharing operating system based on the concept of a single-level memory.Dennis M. Ritchie, "The Evolution of the Unix Time-sharing System", Communications of t ...

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...

and first sold in June 1976. Unlike the SQL systems that emerged in the late 1970s and early 80's, MRDS used a command language only for basic data manipulation, equivalent to the SELECT or UPDATE statements in SQL. Other operations, like creating a new database, or general file management, required the use of a separate command program.

References

*Paul McJones
"Multics Relational Data Store (MRDS)"
Multics software Proprietary database management systems {{Database-software-stub