Performance issue

I use Apache Web Server and PostgreSQL 7.3 to collect data everyday. Now it
has been 5 month since I install that server. 

I wonder why now my web very slow to retrieve and display data? 
When I check the memory, I found that postgreSQL client seem not release
after allocate. I try to find bug on my script, but everything look clean to
me. 

Anyone have experience like me.. please share info with me

Thanks anyway, 


Ricky Sutanto