Translating Temporal SQL to Nested SQL

Abstract

This paper presents a technique for weaving temporal semantics into an SQL query. We assume that a query writer programs a query and then annotates the query with some temporal semantics, such as sequenced or nonsequenced semantics. The annotation is a lightweight temporal statement modifier, it changes the semantics by which the query is evaluated. Annotations can be specified for a wide variety of semantics including sequenced and nonsequenced semantics. We give a denotational semantics for translating SQL queries with temporal annotations into Nested SQL. Nested SQL is SQL with some additional operations. We also describe how the translation is implemented using an ANTLR grammar for SQLite.