[PERFORM] The dreaded semwait on FreeBSD

I have a very heavy OLTP application in the field. We have two PostgreSQL databases (9.0.x)/FreeBSD 8.1/amd64 - one is a listener which just stores data digests, the other is the actual database. The digests from the listener are processed by multi-threaded daemons and inserted into the main data

Re: [PERFORM] New server setup

Set it to use session. I had a similar issue having moved one of the components of our app to use transactions, which introduced an undesired behavior. -Original Message- From: pgsql-performance-ow...@postgresql.org [mailto:pgsql-performance-ow...@postgresql.org] On Behalf Of Niels Kr

Re: [PERFORM] how much postgres can scale up?

Greg's book is highly recommended, and in my opinion a "must" for anyone doing serious work with Postgres. > -Original Message- > From: pgsql-performance-ow...@postgresql.org [mailto:pgsql-performance- > ow...@postgresql.org] On Behalf Of Anibal David Acosta > Sent: Friday, June 10, 2011

[PERFORM] Unused indices

I am trying to clean up our schema by removing any indices which are not being used frequently or at all. Using pgadmin, looking at the statistics for an index, I see various pieces of information: Index Scans, Index Tuples Read, Index Tuples Fetched, Index Blocks Read, and Index Blocks Hit.

[PERFORM] Need some help analyzing some benchmarks

Before I deploy some new servers, I figured I would do some benchmarking. Server is a Dual E5620, 96GB RAM, 16 x 450GB SAS(15K) drives. Controller is an Areca 1680 with 2GB RAM and battery backup. So far I have only run bonie++ since each cycle is quite long (writing 192GB). My data partitio

Re: [PERFORM] Configuration for a new server.

>See how buffers_backend is much larger than buffers_clean, even though >maxwritten_clean is low?  That means the background writer isn't running often >enough to keep up with cleaning things, even though >it does a lot of work >when it does kick in.  In your situation I'd normally do a first

Re: [PERFORM] Configuration for a new server.

There are approximately 50 tables which get updated with almost 100% records updated every 5 minutes - what is a good number of autovacuum processes to have on these? The current server I am replacing only has 3 of them but I think I may gain a benefit from having more. Watch pg_stat_user_tables

Re: [PERFORM] Configuration for a new server.

still gappy knowledge J From: Greg Smith [mailto:g...@2ndquadrant.com] Sent: Tuesday, February 01, 2011 4:54 AM To: Benjamin Krajmalnik Cc: pgsql-performance@postgresql.org Subject: Re: [PERFORM] Configuration for a new server. Benjamin Krajmalnik wrote: have a new set of servers

[PERFORM] Configuration for a new server.

Scott, I don't know if you received my private email, but just in case you did not I am posting the infomration here. I have a new set of servers coming in - Dual Xeon E5620's, 96GB RAM, 18 spindles (1 RAID1 for OS - SATA, 12 disk RAID10 for data - SAS, RAID-1 for logs - SAS, 2 hot spares S

Re: [PERFORM] Hardware recommendations

> -Original Message- > From: Greg Smith [mailto:g...@2ndquadrant.com] > Sent: Saturday, December 11, 2010 2:18 AM > To: Benjamin Krajmalnik > Cc: pgsql-performance@postgresql.org > Subject: Re: [PERFORM] Hardware recommendations > > > What sort of total read

Re: [PERFORM] Hardware recommendations

affect performance. > -Original Message- > From: John W Strange [mailto:john.w.stra...@jpmchase.com] > Sent: Wednesday, December 08, 2010 4:32 PM > To: Benjamin Krajmalnik; pgsql-performance@postgresql.org > Subject: RE: Hardware recommendations > > Ben, > > It woul

[PERFORM] Hardware recommendations

I need to build a new high performance server to replace our current production database server. The current server is a SuperMicro 1U with 2 RAID-1 containers (one for data, one for log, SAS - data is 600GB, Logs 144GB), 16GB of RAM, running 2 quad core processors (E5405 @ 2GHz), Adaptec 5405 C

[PERFORM] Quesion on the use of indexes

A little background - I have various multi-column indexes whenever I have queries which restrict the output based on the values of the 2 fields (for example, a client code and the date of a transaction). Is there a performance gain using this approach as opposed to using 2 separate indexes, one on

Re: [PERFORM] Question of using COPY on a table with triggers

day, July 15, 2010 4:47 PM > To: Benjamin Krajmalnik; pgsql-performance@postgresql.org > Subject: Re: [PERFORM] Question of using COPY on a table with triggers > > > Essentially, we insert a set of columns into a table, and each row > fires > > a trigger function which ca

[PERFORM] Question of using COPY on a table with triggers

First of all, a little background. We have a table which is used as a trigger table for entering and processing data for a network monitoring system. Essentially, we insert a set of columns into a table, and each row fires a trigger function which calls a very large stored procedure which aggrega

Re: [PERFORM] Question about partitioned query behavior

In postgresql.conf, what are your settings for constraint_exclusion? There are 3 settings - on, off, or partition. Mine are set as follows: constraint_exclusion = on# on, off, or partition Under 8.4.4 I had it set to partition, but the behavior was not what I expected so I set

Re: [PERFORM] cpu bound postgresql setup.

ian.us] > Sent: Monday, June 28, 2010 3:45 PM > To: Benjamin Krajmalnik > Cc: Rajesh Kumar Mallah; Kevin Grittner; pgsql- > performa...@postgresql.org > Subject: Re: [PERFORM] cpu bound postgresql setup. > > Benjamin Krajmalnik wrote: > > Rajesh, > > > > I ha

Re: [PERFORM] cpu bound postgresql setup.

Rajesh, I had a similar situation a few weeks ago whereby performance all of a sudden decreased. The one tunable which resolved the problem in my case was increasing the number of checkpoint segments. After increasing them, everything went back to its normal state. > -Original Message- >