System for executing a query having multiple distinct key columns

A system and computer readable medium for executing a query to access data stored in a database, wherein the query includes a plurality of DISTINCT keys, is disclosed. The system and computer readable medium includes a capture module for identifying each of the plurality of DISTINCT keys in the quer...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Chen, Yao-Ching, Fuh, You-Chin, Lebovitz, Allan B, Lee, Li-Mey, Lin, Fen-Ling, Liu, Lee-Chin Hsu, Wang, Yun, Zhen, Binghua
Format: Patent
Sprache:eng
Online-Zugang:Volltext bestellen
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:A system and computer readable medium for executing a query to access data stored in a database, wherein the query includes a plurality of DISTINCT keys, is disclosed. The system and computer readable medium includes a capture module for identifying each of the plurality of DISTINCT keys in the query and a sort module coupled to the capture module for determining if more than one sort is needed to execute the query, performing a first DISTINCT operation on a first DISTINCT key of the plurality of DISTINCT keys, storing data fetched from the first DISTINCT operation in a master workfile only if more than one sort process is needed to execute the query, and utilizing the master workfile to perform subsequent DISTINCT operations on the other of the plurality of DISTINCT keys.