I'm running a steady state test where I am pushing about 600 queries per second through a Posgres 8.3 system on an 8 CPU Linux system. It's a mix of inserts, updates, and deletes on a few tables - the two biggest ones probably have about 200,000 rows.
Harddrive is just a simple, run-of-the-mill desktop drive. Here are parameters that I have changed from defaults: shared_buffers =100MB synchronous_commit=off And, after noting complaints in the log file about checkpoint intervals, I set: checkpoint_segments=10 Then I turned on slow query logging for queries that take more than 1 second, and checkpoint logging. Typically, I see no slow queries. The system handles the load just fine. Once in a while, I'll see a query that takes 3 - 5 seconds. However, once the checkpoint process begins, I get a whole flood of queries that take between 1 and 10 seconds to complete. My throughput crashes to near nothing. The checkpoint takes between 45 seconds and a minute to complete. After the checkpoint completes - the system returns to having very few slow queries, and the keeps up with the load fine. Is there anything I can do to prevent the occasional slow query? Is there anything I can do to prevent (or minimize) the performance impact of the checkpoint? Thanks, Dan -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
