On Oct 11, 2006, at 16:54 , alexei.vladishev@gmail.com wrote:
> I'm author and maintainer of ZABBIX and the manual. I would like to
> add
> some comments to the thread.
[snip]
> I just did the test on PostgreSQL 7.4.12 and MySQL 5.0.22 (MyISAM,
> sorry had no configured InnoDB). Ubuntu 6.0.6, AMD64, 2GB, default
> database settings.
PostgreSQL 7.4 was released in Nov 2003, and 7.4.12 does not (afaik)
include any performance enhancements. MySQL 5.0.22 came out in May
2006 and, despite the low version number, includes a number of
additional features and performance enhancements.
You might start by comparing apples to apples; "apt-get install
postgresql-8.1".
> PostgreSQL does approximately 1600 records per second for the first
> 10000, then 200rps for the first 100k records, and then slower and
> slower downgrading to 10-20 rps(!!!) when reaching 300k.
You are absolutely right that PostgreSQL performs significantly worse
than MySQL at this extremely artificial test.
On my box (Dell PowerEdge 1850, dual Xeon 2.8GHz, 4GB RAM, 10kRPM
SCSI, Linux 2.6.15, Ubuntu) I get 1,100 updates/sec, compared to
10,000 updates/sec with MySQL/InnoDB, using a stock installation of
both. Insert performance is only around 10% worse than MySQL at
around 9,000 rows/sec. Curiously enough, changing shared_buffers,
wal_buffers, effective_cache_size and even fsync seems to have no
effect on update performance, while fsync has a decent effect on
insert performance.
Alexander.