Aggregates in the Temporal Query Language TQuel,

Abstract

This paper defines aggregates in the temporal query language TQuel provides their formal semantics in the tuple relational calculus. A formal semantics for Quel aggregates is defined in the process. Multiple aggregates; aggregates appearing in the where, when, valid, and as-of clauses; nested aggregation; and instantaneous, cumulative, moving window, and unique variants are supported. These aggregates provide a rich set of statistical functions that range over time, while requiring minimal additions to TQuel and its semantics.

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Document Details

Document Type
Technical Report
Publication Date
Jul 27, 1987
Accession Number
ADA189376

Entities

People

  • Ed Mckenize
  • Richard Snodgrass
  • Santiago Gomez

Organizations

  • University of North Carolina at Chapel Hill

Tags

Communities of Interest

  • C4I

DTIC Thesaurus Topics

  • Air Force
  • Application Software
  • Computer Science
  • Computers
  • Database Management Systems
  • Databases
  • Information Science
  • Information Systems
  • Language
  • Law
  • Relational Database Management Systems
  • Relational Databases
  • Software Development
  • Statistical Analysis
  • Time Intervals

Fields of Study

  • Computer science

Readers

  • Computational Linguistics
  • Database Systems and Applications
  • Operations Research