Re: Pinning a table into memory
Tom Lane <tgl@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
To: "David Blood" <david@matraex.com>
Cc: pgsql-general@postgresql.org
Date: 2002-10-04T18:47:47Z
Lists: pgsql-hackers, pgsql-performance
"David Blood" <david@matraex.com> writes: > In Oracle you can Pin large objects into memory to prevent frequent > reloads. Is there anyway to do this with Postgres? I can never understand why people think this would be a good idea. If you're hitting a table frequently, it will stay in memory anyway (either in Postgres shared buffers or kernel disk cache). If you're not hitting it frequently enough to keep it swapped in, then whatever is getting swapped in instead is probably a better candidate to be occupying the space. ISTM that a manual "pin this table" knob would mostly have the effect of making performance worse, whenever the system activity is slightly different from the situation you had in mind when you installed the pin. Having said that, I'll freely concede that our cache management algorithms could use improvement (and there are people looking at that right now). But a manual pin doesn't seem like a better answer. regards, tom lane