Re: [PERFORM] Performance degradation of inserts when database size grows

2011-05-24 Thread Santhakumaran
Tomas Vondra wrote: >Dne 24.5.2011 07:24, Terry Schmitt napsal(a): >> As near as I can tell from your test configuration description, you have >> JMeter --> J2EE --> Postgres. >> Have you ruled out the J2EE server as the problem? This problem may not >> be the database. >> I would take a look a

Re: [PERFORM] Performance degradation of inserts when database size grows

2011-05-24 Thread Greg Smith
On 05/17/2011 08:45 AM, Andrey Vorobiev wrote: 1. How does database size affect insert performance? As indexes grow, it becomes slower to insert into them. It has to navigate all of the indexes on the table to figure out where to add the new row into there, and that navigation time goes up w

Re: [PERFORM] Performance degradation of inserts when database size grows

2011-05-24 Thread Tomas Vondra
Dne 24.5.2011 07:24, Terry Schmitt napsal(a): > As near as I can tell from your test configuration description, you have > JMeter --> J2EE --> Postgres. > Have you ruled out the J2EE server as the problem? This problem may not > be the database. > I would take a look at your app server's health and

Re: [PERFORM] Performance degradation of inserts when database size grows

2011-05-23 Thread Terry Schmitt
As near as I can tell from your test configuration description, you have JMeter --> J2EE --> Postgres. Have you ruled out the J2EE server as the problem? This problem may not be the database. I would take a look at your app server's health and look for any potential issues there before spending too

Re: [PERFORM] Performance degradation of inserts when database size grows

2011-05-23 Thread Tomas Vondra
Dne 23.5.2011 21:05, Robert Haas napsal(a): > On Mon, May 23, 2011 at 2:46 PM, Tomas Vondra wrote: >> Really? He already has 64 checkpoint segments, which is about 1GB of >> xlog data. The real problem is that the amount of buffers to write is >> constantly growing. At the beginning there's 62861

Re: [PERFORM] Performance degradation of inserts when database size grows

2011-05-23 Thread Robert Haas
On Tue, May 17, 2011 at 8:45 AM, Andrey Vorobiev wrote: > 1. How does database size affect insert performance? Well, if your database gets bigger, then your indexes will become deeper, requiring more time to update. But I'm not sure that's your problem here. > 2. Why does number of written buff

Re: [PERFORM] Performance degradation of inserts when database size grows

2011-05-23 Thread Robert Haas
On Mon, May 23, 2011 at 2:46 PM, Tomas Vondra wrote: > Really? He already has 64 checkpoint segments, which is about 1GB of > xlog data. The real problem is that the amount of buffers to write is > constantly growing. At the beginning there's 62861 buffers (500MB) and > at the end there's 137657 b

Re: [PERFORM] Performance degradation of inserts when database size grows

2011-05-23 Thread Tomas Vondra
Dne 23.5.2011 15:30, Shaun Thomas napsal(a): > On 05/17/2011 07:45 AM, Andrey Vorobiev wrote: > >> 2011-05-17 18:55:51 NOVST LOG: checkpoint starting: xlog >> 2011-05-17 18:57:20 NOVST LOG: checkpoint complete: wrote 62861 buffers >> (24.0%); 0 transaction log file(s) added, 0 removed, 0 recycled;

Re: [PERFORM] Performance degradation of inserts when database size grows

2011-05-23 Thread Shaun Thomas
On 05/17/2011 07:45 AM, Andrey Vorobiev wrote: 2011-05-17 18:55:51 NOVST LOG: checkpoint starting: xlog 2011-05-17 18:57:20 NOVST LOG: checkpoint complete: wrote 62861 buffers (24.0%); 0 transaction log file(s) added, 0 removed, 0 recycled; write=89.196 s, sync=0.029 s, total=89.242 s Increase

Re: [PERFORM] Performance degradation of inserts when database size grows

2011-05-21 Thread Leonardo Francalanci
>1. How does database size affect insert performance? >2. Why does number of written buffers increase when database size grows? It might be related to indexes. Indexes size affect insert performance. >3. How can I further analyze this problem? Try without indexes? -- Sent via pgsql-performa

[PERFORM] Performance degradation of inserts when database size grows

2011-05-21 Thread Andrey Vorobiev
Hi, guys. I have following environment configuration - Postgres 8.4.7 with following postresql.conf settings modified: listen_addresses = '*' max_connections = 100 shared_buffers = 2048MB max_prepared_transactions = 100 wal_buffers = 1024kB checkpoi