Re: PostgreSQL performance issues - Mailing list pgsql-hackers
From | Deblauwe Gino |
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Subject | Re: PostgreSQL performance issues |
Date | |
Msg-id | 471CA49A.2000307@useitgroup.com Whole thread Raw |
In response to | PostgreSQL performance issues ("Tiago J. Adami" <adamitj@gmail.com>) |
Responses |
Re: PostgreSQL performance issues
|
List | pgsql-hackers |
Tiago J. Adami schreef: > Hi all, I'm working for a brazillian company developing and > maintaining a ERP sw that uses PostgreSQL as it main OLTP database > system. We're just to start the migration to IBM DB2 because of many > performance issues. I searched the solution for these performance > problems, and can't find anything on the other web foruns. I'll put > them in this post as topics, but first I'll describe how's the ERP > database's schema: - More than 200 tables; - About 10 tables with > about 10,000 transactions and 15,000 new rows per day; - These 10 > tables has at least 12 table indexes and 3 triggers; - Many of our > customer servers uses AMD64 processors running Red Hat Enterprise > (with EXT3), but we have some using Xeon processors and Windows 2003 > Server (NTFS), and the issues still the same; - All servers have at > least 1 Gb of dedicated RAM, with no virtualization; - All servers > uses at least 2 disks on RAID 0 (Ultra-SCSI disks); - Database > encoding: LATIN 1. *The issue topics:* 1) As the database grows on our > customers, lower performance occurs. After one week of use, the I/O on > database is extremely high. It appears that VACUUM FULL and/or VACUUM > ANALYZE doesn't work on this databases. 2) We have a very complex view > mount on other views. When we cancel a simple SELECT on this top-level > view (expecting return a max. of 100 rows for example) the PostgreSQL > process starts a infinite loop (we left more than 4 days and the loop > doesn't stops), using 100% of all processors on the server. 3) On > these servers, the disk usage grows very small than the records loaded > into database. For example, after restoring a backup, the database DIR > have about 40 Gb (with all indexes created). After one week of use, > and about 500,000 new records on tables, the database size grows to > about 42 Gb, but on Windows 2003 Server we can see the high > fragmentation of disk (maybe on linux this occurs too). 4) VACUUM FULL > and/or VACUUM ANALYZE appears to doesn't work perfectly. *The > temporary (but extensive) solution:* I have seem that one action could > solve this problems for a short time. It is as follows: 1) Create a > database dump into a .SQL plain text file; 2) Drop the OTLP original > database; 3) Create a new database using the original name; 4) > Restores the .SQL file with psql. The cost of use PostgreSQL database > on our sw came to a very high levels, so we're evaluating the same > database schema and data on other databases as IBM DB2 9, and these > issues doesn't work. However, we need solve this problems on PgSQL, as > exists many customers who will not migrate to DB2. Anyone can help me? > ------------------------------------------------------------------------ > View this message in context: PostgreSQL performance issues > <http://www.nabble.com/PostgreSQL-performance-issues-tf4670379.html#a13341797> > Sent from the PostgreSQL - hackers mailing list archive > <http://www.nabble.com/PostgreSQL---hackers-f780.html> at Nabble.com. a) I didn't see a reindex in your mail. That's why a backup and a restore work and a vacuum doesn't http://www.postgresql.org/docs/current/static/sql-reindex.html Do this at least daily with that many inserts b) Which version do you run of postgres? pg82 is a lot faster then previous versions, pg83 will be again a lot faster when it comes out c) Fragmentation won't happen on linux as far as I know, but if you want to be faster why do you use the slowest filesystem ever? ReiserFS is a lot better. On windows => frequent defragmenting, it's said that with NTFS it's not necessary anymore, but I don't believe it.
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