From: Pierre C <lists@peufeu.com>
To: Greg Smith <greg@2ndquadrant.com>
To: jgardner@jonathangardner.net <jgardner@jonathangardner.net>
Cc: pgsql-performance@postgresql.org
Subject: Re: PostgreSQL as a local in-memory cache
Date: Wed, 16 Jun 2010 13:22:50 +0200
Message-ID: <op.ved4kcv3eorkce@apollo13> (raw)
In-Reply-To: <4C188AD4.20209@2ndquadrant.com>
References: <cb0fb58c-9134-4314-a1d0-08fc39f911a6@40g2000pry.googlegroups.com>
<87bpbcpabg.fsf@cbbrowne-laptop.afilias-int.info>
<4C17A417.2040600@noao.edu>
<87ocfcnqmk.fsf@cbbrowne-laptop.afilias-int.info>
<4C180A3B.7090905@agliodbs.com>
<4634b12c-749f-4605-9d95-121b8e2bd9e4@k17g2000pro.googlegroups.com>
<4C188AD4.20209@2ndquadrant.com>
FYI I've tweaked this program a bit :
import psycopg2
from time import time
conn = psycopg2.connect(database='peufeu')
cursor = conn.cursor()
cursor.execute("CREATE TEMPORARY TABLE test (data int not null)")
conn.commit()
cursor.execute("PREPARE ins AS INSERT INTO test VALUES ($1)")
cursor.execute("PREPARE sel AS SELECT 1")
conn.commit()
start = time()
tx = 0
N = 100
d = 0
while d < 10:
for n in xrange( N ):
cursor.execute("EXECUTE ins(%s)", (tx,));
#~ conn.commit()
#~ cursor.execute("EXECUTE sel" );
conn.commit()
d = time() - start
tx += N
print "result : %d tps" % (tx / d)
cursor.execute("DROP TABLE test");
conn.commit();
Results (Core 2 quad, ubuntu 10.04 64 bits) :
SELECT 1 : 21000 queries/s (I'd say 50 us per query isn't bad !)
INSERT with commit every 100 inserts : 17800 insets/s
INSERT with commit every INSERT : 7650 tps
fsync is on but not synchronous_commit.
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To: pgsql-performance@postgresql.org
Cc: lists@peufeu.com, greg@2ndquadrant.com, jgardner@jonathangardner.net
Subject: Re: PostgreSQL as a local in-memory cache
In-Reply-To: <op.ved4kcv3eorkce@apollo13>
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