To: "Merlin Moncure" <merlin.moncure@rcsonline.com>
Cc: "Marc Cousin" <mcousin@sigma.fr>,
	pgsql-performance@postgresql.org, pgsql-hackers-win32@postgresql.org
Subject: Re: [PERFORM] insert performance for win32 
In-reply-to: <6EE64EF3AB31D5448D0007DD34EEB3417DD290@Herge.rcsinc.local> 
References: <6EE64EF3AB31D5448D0007DD34EEB3417DD290@Herge.rcsinc.local>
Comments: In-reply-to "Merlin Moncure" <merlin.moncure@rcsonline.com>
	message dated "Wed, 07 Sep 2005 09:08:18 -0400"
Date: Wed, 07 Sep 2005 11:02:13 -0400
Message-ID: <27312.1126105333@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>

"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