Re: [PERFORM] Postgres benchmarking with pgbench

2009-03-19 Thread Jignesh K. Shah
m...@bortal.de wrote: Hi Greg, thanks a lot for your hints. I changed my config and changed raid6 to raid10, but whatever i do, the benchmark breaks down at a scaling factor 75 where the database is "only" 1126MB big. Here are my benchmark Results (scaling factor, DB size in MB, TPS) using

Re: [PERFORM] Postgres benchmarking with pgbench

2009-03-19 Thread Scott Carey
On 3/19/09 2:25 PM, "m...@bortal.de" wrote: > > Here is my config (maybe with some odd setting): > http://pastebin.com/m5d7f5717 > > I played around with: > - max_connections > - shared_buffers > - work_mem > - maintenance_work_mem > - checkpoint_segments > - effective_cache_size > > ..but wh

Re: [PERFORM] Postgres benchmarking with pgbench

2009-03-19 Thread Scott Marlowe
On Thu, Mar 19, 2009 at 3:25 PM, m...@bortal.de wrote: > Hi Greg, > > thanks a lot for your hints. I changed my config and changed raid6 to > raid10, but whatever i do, the benchmark breaks down at a scaling factor 75 > where the database is "only" 1126MB big. > > Here are my benchmark Results (sc

Re: [PERFORM] Postgres benchmarking with pgbench

2009-03-19 Thread m...@bortal.de
Hi Greg, thanks a lot for your hints. I changed my config and changed raid6 to raid10, but whatever i do, the benchmark breaks down at a scaling factor 75 where the database is "only" 1126MB big. Here are my benchmark Results (scaling factor, DB size in MB, TPS) using: pgbench -S -c X -t

Re: [PERFORM] Postgres benchmarking with pgbench

2009-03-16 Thread Scott Marlowe
On Mon, Mar 16, 2009 at 10:17 PM, Greg Smith wrote: > On Tue, 17 Mar 2009, Gregory Stark wrote: > >> I think pgbench is just not that great a model for real-world usage > > pgbench's default workload isn't a good model for anything.  It wasn't a > particularly real-world test when the TPC-B it's b

Re: [PERFORM] Postgres benchmarking with pgbench

2009-03-16 Thread Greg Smith
On Tue, 17 Mar 2009, Gregory Stark wrote: I think pgbench is just not that great a model for real-world usage pgbench's default workload isn't a good model for anything. It wasn't a particularly real-world test when the TPC-B it's based on was created, and that was way back in 1990. And pg

Re: [PERFORM] Postgres benchmarking with pgbench

2009-03-16 Thread Gregory Stark
Greg Smith writes: > On Mon, 16 Mar 2009, Gregory Stark wrote: > >> Why would checkpoints force out any data? It would dirty those pages and then >> sync the files marking them clean, but they should still live on in the >> filesystem cache. > > The bulk of the buffer churn in pgbench is from the

Re: [PERFORM] Postgres benchmarking with pgbench

2009-03-16 Thread Greg Smith
On Mon, 16 Mar 2009, Gregory Stark wrote: Why would checkpoints force out any data? It would dirty those pages and then sync the files marking them clean, but they should still live on in the filesystem cache. The bulk of the buffer churn in pgbench is from the statement that updates a row in

Re: [PERFORM] Postgres benchmarking with pgbench

2009-03-16 Thread Gregory Stark
Greg Smith writes: > On Mon, 16 Mar 2009, m...@bortal.de wrote: > >> Any idea why my performance colapses at 2GB Database size? I don't understand how you get that graph from the data above. The data above seems to show your test databases at 1.4GB and 2.9GB. There are no 1GB and 2GB data points

Re: [PERFORM] Postgres benchmarking with pgbench

2009-03-16 Thread Greg Smith
On Mon, 16 Mar 2009, m...@bortal.de wrote: Any idea why my performance colapses at 2GB Database size? pgbench results follow a general curve I outlined at http://www.westnet.com/~gsmith/content/postgresql/pgbench-scaling.htm and the spot where performance drops hard depends on how big of a w

[PERFORM] Postgres benchmarking with pgbench

2009-03-16 Thread m...@bortal.de
Hello List, i would like to pimp my postgres setup. To make sure i dont have a slow hardware, i tested it on three diffrent enviorments: 1.) Native Debian Linux (Dom0) and 4GB of RAM 2.) Debian Linux in Xen (DomU) 4GB of RAM 3.) Blade with SSD Disk 8GB of RAM Here are my results: http://i39.ti