Oracle was the first commercial RDBMS (1979), with an early version of SQL. At that time every mainframe and minicomputer company offered one or more “databases,” often little more than file managers with a library of utilities. ISAM was a popular model but that describes a lot of data management systems, not a product or standard.

All commercial databases pre-Oracle were non-SQL. Watching that history get rediscovered and pushed as an improvement by people mostly too young to know better — so-called NoSQL databases — brings to mind Alan Kay’s quip about the software industry constantly reinventing the flat tire.

The hash-based Pick OS/database came out before Oracle but only ran on a few computers from Microdata and later Pr1me and Honeywell. Pick-based systems remained popular into the early 2000s in some sectors. A friend of mine still works on one, for a state government agency.

You could construct a database management system from the ISAM-based libraries for COBOL or Fortran, but I wouldn’t call those database management systems comparable to Oracle. Mostly they didn’t have a query language per se — you had to write code to get anything in or out. And they ran as part of the application process, not as a separate server dedicated to running the database engine.

I was thinking Db2 might have been a little earlier but you're right. And it's fair that the earlier databases definitely lacked elements of what we'd consider a database management system today even if they handled a lot of the low-level database heavy lifting for companies.