The Temporal Query Language TQuel

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324 Scopus citations


Recently, attention has been focused on temporal databases, representing an enterprise over time. We have developed a new language, Tquel, to query a temporal database. TQuel was designed to be a minimal extension, both syntactically and semantically, of Quel, the query language in the Ingres relational database management system. This paper discusses the language informally, then provides a tuple relational calculus semantics for the TQuel statements that differ from their Quel counterparts, including the modification statements. The three additional temporal constructs defined in Tquel are shown to be direct semantic analogues of Quel's where clause and target list. We also discuss reducibility of the semantics to Quel's semantics when applied to a static database. TQuel is compared with ten other query languages supporting time.

Original languageEnglish (US)
Pages (from-to)247-298
Number of pages52
JournalACM Transactions on Database Systems (TODS)
Issue number2
StatePublished - Jun 1 1987


  • Historical database
  • Quel
  • relational calculus
  • relational model
  • rollback database
  • temporal database
  • tuple calculus

ASJC Scopus subject areas

  • Information Systems


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