From: | Shiby Thomas <sthomas(at)cise(dot)ufl(dot)edu> |
---|---|
To: | The Hermit Hacker <scrappy(at)hub(dot)org> |
Cc: | pgsql-hackers(at)postgreSQL(dot)org |
Subject: | Re: [HACKERS] postgres performance |
Date: | 1998-01-15 18:33:08 |
Message-ID: | 199801151833.NAA10288@cise.ufl.edu |
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Lists: | pgsql-hackers |
=> There may be optimizations in the 2.6 libraries that would improve
=> performance, but I wouldn't suspect that it would make *that* big of a
=> difference. What is your SQL/join statemnt? How are you running
=> postmaster? What does 'explain' show?
=>
The complete query is this:
select item1, item2, count(t1.tid) into table f2_temp from data t1, data t2,
c2
where t1.item = c2.item1 and t2.item = c2.item2 and t1.tid = t2.tid group by
ite
m1, item2
data is a table with 2 integer columns (tid, item) and it has ~300K records
c2 is a table (item1, item2), both integers and has ~1.5K records.
I was directly running postgres with the -B and -S flags to give more buffers
and sortMem. I also tried several join plans by the -f flags. Hash join works
the best and that itself is too slow (perhaps due to the self join)
--shiby
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