Re: COPY from question
Tom Lane <tgl@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Kevin Brown <kevin@sysexperts.com>
Cc: pgsql-hackers@postgresql.org
Date: 2004-02-03T15:10:29Z
Lists: pgsql-hackers, pgsql-performance
Kevin Brown <kevin@sysexperts.com> writes: > Slavisa Garic wrote: >> Using pg module in python I am trying to run the COPY command to populate >> the large table. I am using this to replace the INSERT which takes about >> few hours to add 70000 entries where copy takes minute and a half. > That difference in speed seems quite large. Too large. Are you batching > your INSERTs into transactions (you should be in order to get good > performance)? Do you have a ton of indexes on the table? Does it have > triggers on it or some other thing (if so then COPY may well wind up doing > the wrong thing since the triggers won't fire for the rows it > inserts)? COPY *does* fire triggers, and has done so for quite a few releases. My bet is that the issue is failing to batch individual INSERTs into transactions. On a properly-set-up machine you can't get more than one transaction commit per client per disk revolution, so the penalty for trivial transactions like single inserts is pretty steep. regards, tom lane