Need input on postgres used for phpBB

Hi ALL,

we have a site that uses postgres as a backend for a forum. this forum does a lot of deletes, selects and inserts. just recently for some reason postgres eats a lot of processing power..

here are some tech-details:

tcpip_socket = true
max_connections = 260
superuser_reserved_connections = 2

port = 5432
shared_buffers = 40102
sort_mem = 4096
effective_cache_size = 4000

#fsync = true
#wal_sync_method = fsync

#log_statement = true
#log_duration = true

#syslog = 0 # range 0-2
#syslog_facility = 'LOCAL0'
#syslog_ident = 'postgres'

#
# Locale settings
#
# (initialized by initdb -- may be changed)
LC_MESSAGES = 'en_US.UTF-8'
LC_MONETARY = 'en_US.UTF-8'
LC_NUMERIC = 'en_US.UTF-8'
LC_TIME = 'en_US.UTF-8'

** im doing an hourly vaccum
0 1-23 * * * bin/vacuumdb --port 5432 --analyze -d myforumdb 1>/dev/null 2>/tmp/vaccum_hourly.log

--> is the hourly vaccum necessary? for some reason vaccum takes to much time..

input on how to make things work fast is highly appreciated..

tia,