http://www.zabbix.com/manual/v1.1/install.php
in section PostgreSQL vs MySQL :
[quoting]
Regarding the choice between PostgreSQL and MySQL, MySQL is
recommended for several reasons:
* MySQL is faster
recent benchmarks using ZABBIX clearly show that PostgreSQL
(7.1.x) is at least 10 times slower than MySQL (3.23.29)
Note: These results are predictable. ZABBIX server processes use
simple SQL statements like single row INSERT, UPDATE and simple SELECT
operators. In such environment, use of advanced SQL engine (like
PostgreSQL) is overkill.
* no need to constantly run resource-hungry command "vacuum" for MySQL
* MySQL is used as a primary development platform.
If you do use PostgreSQL, zabbix_server will periodically (defined in
HousekeepingFrequency) execute command vacuum analyze.
[done]
anybody know these guys? this is right off the mysql anti-postgresql
advocacy page.
merlin