Multics Relational Data Store

{{Short description|Relational database for the Multics operating system}}

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The Multics Relational Data Store, or MRDS for short, was the first commercial relational database management system. It was written in PL/1 by Honeywell for the Multics operating system and first sold in June 1976.{{cite news |last1=Leavitt |first1=Don |title=MDBM' Backs Network, Relational Approaches |url=https://books.google.com/books?id=OohpOVF5L-IC&pg=PA11 |work=Computerworld |publisher=IDG Enterprise |date=6 September 1976 |language=en}} Unlike the SQL systems that emerged in the late 1970s and early 80s, 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.