From: Tom Lane <tgl@sss.pgh.pa.us>
To: Kelly Burkhart <kelly@tradebotsystems.com>
Cc: mark@mark.mielke.cc, Merlin Moncure <merlin.moncure@rcsonline.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: 8.x index insert performance
Date: Mon, 31 Oct 2005 16:18:47 -0500
Message-ID: <19065.1130793527@sss.pgh.pa.us> (raw)
In-Reply-To: <1130792391.7026.55.camel@krb06.tradebot.com>
References: <6EE64EF3AB31D5448D0007DD34EEB3417DD725@Herge.rcsinc.local>
<20051031193547.GA3311@mark.mielke.cc>
<18647.1130790629@sss.pgh.pa.us>
<1130792391.7026.55.camel@krb06.tradebot.com>
Kelly Burkhart <kelly@tradebotsystems.com> writes:
> Ha! So I'm creating an index 98% full of nulls! Looks like this is
> easily fixed with partial indexes.
Still, though, it's not immediately clear why you'd be seeing a severe
dropoff in insert performance after 50M rows. Even though there are
lots of nulls, I don't see why they'd behave any worse for insert speed
than real data. One would like to think that the insert speed would
follow a nice O(log N) rule.
Are you doing the inserts all in one transaction, or several? If
several, could you get a gprof profile of inserting the same number of
rows (say a million or so) both before and after the unexpected dropoff
occurs?
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, kelly@tradebotsystems.com, merlin.moncure@rcsonline.com
Subject: Re: 8.x index insert performance
In-Reply-To: <19065.1130793527@sss.pgh.pa.us>
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