Message-ID: <9452092.post@talk.nabble.com>
Date: Tue, 13 Mar 2007 03:55:12 -0700 (PDT)
From: femski <hypertree@yahoo.com>
To: pgsql-performance@postgresql.org
Subject: Postgres batch write very slow - what to do
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit


Folks !

I have a batch application that writes approx. 4 million rows into a narrow
table. I am using JDBC addBatch/ExecuteBatch with auto commit turned off.
Batch size is 100. So far I am seeing Postgres take roughly five times the
time it takes to do this in the Oracle. 

I have played with many parameters. Only one that seems to have any affect
is fsync - but thats only 10% or so. 
Initially I got the warning that checkpoints were happening too often so I
increased the segments to 24. Warnings stopped, but no real improvement in
performance.

Is postgres really that slow ? What am I missing ? 

Here are the changes to my postgressql.cong file. 

shared_buffers = 768MB
work_mem = 256MB 
maintenance_work_mem = 128MB
fsync = off 

checkpoint_segments = 24
autovacuum = on 

Thank you,

-Sanjay
-- 
View this message in context: http://www.nabble.com/Postgres-batch-write-very-slow---what-to-do-tf3395195.html#a9452092
Sent from the PostgreSQL - performance mailing list archive at Nabble.com.