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Conference turris::digital_unix

Title:	DIGITAL UNIX(FORMERLY KNOWN AS DEC OSF/1)
Notice:	Welcome to the Digital UNIX Conference
Moderator:	SMURF::DENHAM

Created:	Thu Mar 16 1995
Last Modified:	Fri Jun 06 1997
Last Successful Update:	Fri Jun 06 1997
Number of topics:	10068
Total number of notes:	35879

9333.0. "performance of DB query" by BEJVC::ARTHURWANG () Mon Mar 31 1997 02:47

    Hi!
    
    A customer asked me a question about performance of database's query:
    
    The three same query's batch(including 50 queries)were submitted
    sequently using three accounts. But the result was very strange(see the
    following),
    
             first query's batch          second       third
    real           187                      6.5         6.3
    
    The customer's question is: why the first batch's time cost was longer
    than the second and third?
    
    Hope your reply?
    
    Arthur and Tony

T.R Title User Personal
Name Date Lines

9333.1 It's in memory for users 2 and 3 PERFOM::MORGENSTEIN Achilles loved Petroclus Mon Mar 31 1997 10:09 8

T.R	Title	User	Personal Name	Date	Lines
9333.1	It's in memory for users 2 and 3	PERFOM::MORGENSTEIN	Achilles loved Petroclus	`Mon Mar 31 1997 10:09`	8
	You don't say what database you're using, but most databases cache their information. The first query had to get the data off disk. All subsequent queries will read it out of database-cache (i.e. memory) unless the data gets knocked out for some reason. Ruth


You don't say what database you're using, but most databases cache their 
information.  The first query had to get the data off disk.  All subsequent
queries will read it out of database-cache (i.e. memory) unless the data
gets knocked out for some reason.

Ruth