i set the auto vacuum option to enable. but my database size(hard-disk space) still increased from 420MB to 440MB in 8 hours. most of the operations in this database are the "Select" query command, just few of "Update or Insert". why it can be increased so strongly? after i executed the command " vaccumdb -f -z testdb", but the size just decreased 1 or 2MB... what's the problem? how to know which command(select,insert....) takes the hurge loading to database in this time? computer environment: System: Red Hat Enterprise 4 Postgresql Server: 8.0.13 count of client connected : about 100 pc