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From: tslee@oracle.uucp (Terry S. Lee)
Newsgroups: comp.databases
Subject: Re: Oracle vs. Sybase on Sun 4:  That much difference!?
Message-ID: <1990Mar22.044059.26644@oracle.com>
Date: 22 Mar 90 04:40:59 GMT
References: <1990Mar14.205620.11636@lia> <106035@pyramid.pyramid.com> <404@ohsuhcx.ohsu.edu>
Reply-To: tslee@oracle.UUCP (Terry S. Lee)
Distribution: na
Organization: Oracle Corporation, Belmont, CA
Lines: 23

In article <404@ohsuhcx.ohsu.edu> sjm@ohsuhcx.UUCP (Sandra McMaster) writes:
>In article <106035@pyramid.pyramid.com> eric@pyramid.pyramid.com (Eric Bergan) writes:
>>In article <1990Mar14.205620.11636@lia> thomas@lia.UUCP (Chris Thomas) writes:
>>>In Sybase, this completes in anywhere from
>>>3 to 7 minutes (depending on other load), but Oracle seems to take
>>>several -hours- to do the same thing.
>>
>>	Almost certainly, Sybase and Oracle are picking different
>>query execution plans for the join. 
>
>There is an EXPLAIN facility (mostly undocumented, I believe) in
>Oracle V6 which will allow you to determine how the query is being
>executed.  I have a paper which explains the EXPLAIN facility.  Let
>me know if you are interested... I'll check with the author and see
>if I can duplicate it.
>
>Sandra McMaster
>Oregon Health Sciences University
>sjm@ohsu.edu
>{nosun, tektronix, ogicse, qiclab}!ohsuhcx!sjm

EXPLAIN and TKPROF are documented in Chapter 7 of "Performance Tuning Guide",
Part # 5317-v6.0