From: Tom Lane <tgl@sss.pgh.pa.us>
To: Merlin Moncure <merlin.moncure@rcsonline.com>
Cc: Marc Cousin <mcousin@sigma.fr>
Cc: pgsql-performance@postgresql.org
Cc: pgsql-hackers-win32@postgresql.org
Subject: Re: [PERFORM] insert performance for win32
Date: Wed, 07 Sep 2005 11:02:13 -0400
Message-ID: <27312.1126105333@sss.pgh.pa.us> (raw)
In-Reply-To: <6EE64EF3AB31D5448D0007DD34EEB3417DD290@Herge.rcsinc.local>
References: <6EE64EF3AB31D5448D0007DD34EEB3417DD290@Herge.rcsinc.local>
"Merlin Moncure" <merlin.moncure@rcsonline.com> writes:
> ok, I've been in crunching profile profile graphs, and so far have been
> only been able to draw following conclusions.
> For bulk, 'in-transaction' insert:
> 1. win32 is slower than linux. win32 time for each insert grows with #
> inserts in xact, linux does not (or grows much slower). Win32 starts
> out about 3x slower and grows to 10x slower after 250k inserts.
Just to be clear: what you were testing was
BEGIN;
INSERT ... VALUES (...);
repeat insert many times
COMMIT;
with each statement issued as a separate PQexec() operation, correct?
Was this set up as a psql script, or specialized C code? (If a psql
script, I wonder whether it's psql that's chewing the time.)
> 2. ran a 50k profile vs. 250k profile. Nothing jumps out as being
> slower or faster: most time is spent in yyparse on either side. From
> this my preliminary conclusion is that there is something going on in
> the win32 api which is not showing in the profile.
Hmm. Client/server data transport maybe? It would be interesting to
try inserting the same data in other ways:
* COPY from client
* COPY from disk file
* INSERT/SELECT from another table
and see whether you see a similar slowdown.
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, merlin.moncure@rcsonline.com, mcousin@sigma.fr, pgsql-hackers-win32@postgresql.org
Subject: Re: [PERFORM] insert performance for win32
In-Reply-To: <27312.1126105333@sss.pgh.pa.us>
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