Memory requirements for web-project

Hello pgsql-general,

i need to calculate the memory requirement if i am using apache+pgsql.

Lets assume that i want 160.000 hits a day and pgsql takes 3 seconds
to work for each client, how much ram is required specially for pgsql?

I think I have to calculate the memory requiremend for a specific time
period.

160.000 hits are wanted, so I calculate 160.000 div 24 = approx 6666
Hits a hour, div 60 = 111 Hits a minute, = 1,85 Hits per secound.

lets round it up to 2 hits per secound. So I calculate now
2 hits per second * 3 seconds for a client
= 6 processes at the same time,

is that correct?

If so, how much is the memory requiremend? I have seen with "TOP" that
pgsql requires 5000kb for a request, but it is used per client (new processes for
each new client-request?)

--
Boris
www.x-itec.de