Re: [PERFORM] Performance

2011-04-28 Thread Joshua Berkus
All, > The easiest place to start is by re-using the work already done by the > TPC for benchmarking commercial databases. There are ports of the TPC > workloads to PostgreSQL available in the DBT-2, DBT-3, and DBT-5 > tests; Also EAStress, which I think the project still has a license for. The

Re: [PERFORM] Performance

2011-04-28 Thread Tomas Vondra
Dne 27.4.2011 23:55, Greg Smith napsal(a): > The easiest place to start is by re-using the work already done by the > TPC for benchmarking commercial databases. There are ports of the TPC > workloads to PostgreSQL available in the DBT-2, DBT-3, and DBT-5 tests; > see http://wiki.postgresql.org/wi

Re: [PERFORM] VX_CONCURRENT flag on vxfs( 5.1 or later) for performance for postgresql?

2011-04-28 Thread Greg Smith
On 04/27/2011 11:33 PM, HSIEN-WEN CHU wrote: When database files are on a VxFS filesystem, performance can be significantly improved by setting the VX_CONCURRENT cache advisory on the file according to vxfs document, That won't improve performance, and it's not safe either. VX_CONCURRENT

Re: [PERFORM] reducing random_page_cost from 4 to 2 to force index scan

2011-04-28 Thread Jeff Janes
On Wed, Apr 27, 2011 at 5:19 PM, Sok Ann Yap wrote: > > I understand the need to tune PostgreSQL properly for my use case. > What I am curious about is, for the data set I have, under what > circumstances (hardware/workload/cache status/etc) would a sequential > scan really be faster than an index

Re: [PERFORM] Order of tables

2011-04-28 Thread Heikki Linnakangas
On 28.04.2011 12:20, Rishabh Kumar Jain wrote: How the tables must be ordered in the list of tables in from statement? There is no difference in performance, if that's what you mean. (If not, then pgsql-novice or pgsql-sql mailing list would've be more appropriate) -- Heikki Linnakangas

Re: [PERFORM] Order of tables

2011-04-28 Thread Robert Klemme
On Thu, Apr 28, 2011 at 11:20 AM, Rishabh Kumar Jain wrote: > How the tables must be ordered in the list of tables in from statement? > To achieve what? Generally there is no requirement for a particular ordering of relation names in SQL. Cheers robert -- remember.guy do |as, often| as.you_

Re: [PERFORM] reducing random_page_cost from 4 to 2 to force index scan

2011-04-28 Thread Samuel Gendler
On Wed, Apr 27, 2011 at 5:19 PM, Sok Ann Yap wrote: > On Thu, Apr 28, 2011 at 7:23 AM, Kevin Grittner > > > I understand the need to tune PostgreSQL properly for my use case. > What I am curious about is, for the data set I have, under what > circumstances (hardware/workload/cache status/etc) wou

[PERFORM] Order of tables

2011-04-28 Thread Rishabh Kumar Jain
How the tables must be ordered in the list of tables in from statement?

Re: [PERFORM] Performance

2011-04-28 Thread Sethu Prasad
Just want to share the DBT(2&5) thing http://archives.postgresql.org/pgsql-performance/2011-04/msg00145.php http://sourceforge.net/mailarchive/forum.php?forum_name=osdldbt-general&max_rows=25&style=nested&viewmonth=201104 On Wed, Apr 27, 2011 at 11:55 PM, Greg Smith wrote: > Tomas Vondra wrot