System R: an architectural overview

System R is an experimental data base management system designed and built as part of a program of research in the relational model of data. System R includes the Relational Data System (RDS) and the Research Storage System (RSS). The RDS supports a flexible spectrum of binding times, ranging from precompilation of 'canned transactions' to on-line executions of ad hoc queries. RSS on the other hand provides multiple paths for accessing data including sequential scans, indexes, sorting, and pointer chains, and, in addition, provides service for locking, recovery, and transaction management.