Re: The never ending quest for clarity on shared_buffers

On Thu, 2004-10-07 at 08:26, Paul Ramsey wrote:
> The shared_buffers are shared (go figure) :).  It is all one pool shared
> by all connections.

Yeah, I thought this was pretty clear. Doug, can you elaborate on where
you saw the misleading docs?

> The sort_mem and vacuum_mem are *per*connection* however, so when
> allocating that size you have to take into account your
> expected number of concurrent connections.

Allocations of size `sort_mem' can actually can actually happen several
times within a *single* connection (if the query plan happens to involve
a number of sort steps or hash tables) -- the limit is on the amount of
memory that will be used for a single sort/hash table. So choosing the
right figure is actually a little more complex than that.

-Neil