Re: [HACKERS] postgres performance

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
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
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

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message D'Arcy J.M. Cain 1998-01-15 18:33:40 Re: [HACKERS] Re: [QUESTIONS] Arrays (inserting and removing)
Previous Message Bruce Momjian 1998-01-15 18:23:07 Re: [HACKERS] postgres performance