How much memory is PostgreSQL using

PostgreSQL 8.4.3

OS: Linux Red Hat 4.x

I changed my strategy with PostgreSQL recently to use a large segment of
memory for shared buffers with the idea of caching disk blocks. How can
I see how much memory PostgreSQL is using for this?

I tried:

ps aux | grep post | sort -k4

This lists the processes using memory at the bottom. Are they sharing
memory or using individual their own blocks of memory?

When I do top I see that VIRT is the value of my shared buffers plus a
tiny bit. I see %MEM is only 2.4%, 2.6%, 1.0%,1.5%, and 1.1% for all of
the running processes. Do I add these percentages up to see what amount
of VIRT I am really using?

Or is there some way to ask PostgreSQL how much memory are you using to
cache disk blocks currently?

When you do a PG_DUMP does PostgreSQL put the disk blocks into shared
buffers as it runs?

Thanks,

Lance Campbell

Software Architect/DBA/Project Manager

Web Services at Public Affairs

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