Temporal PSM

Richard T. Snodgrass, Dengfeng Gao, Rui Zhang, Stephen W. Thomas, Jennifer Dempsey

Abstract:

Persistent Stored Modules
Temporal PSM is an extension of persistent stored modules (PSM) in SQL to add temporal support [1]. Persistent stored modules make up the Turing-complete portion of SQL and provide structured programming constructs (e.g., IF, WHILE). PSM also includes support for procedures which can be called directly and functions which can be invoked from within an SQL query (modification, view, cursor, etc.). Temporal PSM requires minor new syntax beyond that already in SQL/Temporal to define and to invoke PSM procedures and functions, thereby extending the current, sequenced, and nonsequenced semantics of queries to such routines.
Temporal query languages are now fairly well understood, as indicated by support in prominent DBMSes. Procedures and functions in the form of Persistent Stored Modules (PSM) have been included in the SQL standard and implemented in numerous DBMSes [2].

The SQL standard includes stored routines in part 4:...