table partitioning & max_locks_per_transaction

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hello All --

I have implemented table partitioning in order to increase performance in my database-backed queuing system. My queue is partitioned by job_id into separate tables that all inherit from a base "queue" table.

Things were working swimmingly until my system started managing thousands of jobs. As soon as I had ~1070 queue subtables, queries to the main queue table would fail with:

"out of shared memory HINT: You might need to increase max_locks_per_transaction"

I found this thread on the archives:

	http://archives.postgresql.org/pgsql-general/2007-08/msg01992.php

Still, I have a few questions/problems:

1) We've already tuned postgres to use ~2BG of shared memory -- which is SHMAX for our kernel. If I try to increase max_locks_per_transaction, postgres will not start because our shared memory is exceeding SHMAX. How can I increase max_locks_per_transaction without having my shared memory requirements increase?

2) Why do I need locks for all of my subtables, anyways? I have constraint_exclusion on. The query planner tells me that I am only using three tables for the queries that are failing. Why are all of the locks getting allocated? Is there any way to prevent this?

Many thanks in advance for any and all help anyone can provide!

Brian

--
Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-performance

[Postgresql General]     [Postgresql PHP]     [PHP Users]     [PHP Home]     [PHP on Windows]     [Kernel Newbies]     [PHP Classes]     [PHP Books]     [PHP Databases]     [Yosemite]

  Powered by Linux