Thread

Re: [HACKERS] postgres performance

Shiby Thomas <sthomas@cise.ufl.edu> — 1998-01-15T18:33:08Z

=> 	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