Re: Does RelCache/SysCache shrink except when relations are deleted?

From: "Alvaro Herrera" <alvherre@commandprompt.com>
> You don't really know this; some operating systems (Linux in particular)
> does not show shared memory as in use by a process until it is accessed.
> It may very well have well over 1.6 GB of shared_buffers, yet not show
> that in VIRT.

Oh, really? When I started psql just after I set shared_buffers to 2500MB 
and ran pg_ctl start, "ps -o vsz -p postgres_PID" showed about 2500MB+some. 
ps's vsz is also the amount of virtual memory. But I want to know the 
shared_buffers setting.

Anyway, I'd appreciate if anyone could tell me about RelCache/SysCache. As 
far as I read the code, PostgreSQL seems to use memory for RelCache/SysCache 
without limit until the relations are dropped.

Regards
MauMau