From: | "Tomas Vondra" <tv(at)fuzzy(dot)cz> |
---|---|
To: | "Claudio Freire" <klaussfreire(at)gmail(dot)com> |
Cc: | "Stefan Keller" <sfkeller(at)gmail(dot)com>, "Wales Wang" <wormwang(at)yahoo(dot)com>, "Jeff Janes" <jeff(dot)janes(at)gmail(dot)com>, "pgsql-performance(at)postgresql(dot)org" <pgsql-performance(at)postgresql(dot)org>, "Stephen Frost" <sfrost(at)snowman(dot)net> |
Subject: | Re: [PERFORM] Re: [PERFORM] Re: 回复: [PERFORM] PG as in-memory db? How to warm up and re-populate buffers? How to read in all tuples into memory? |
Date: | 2012-02-28 13:38:57 |
Message-ID: | 8da9b15646d973a5ee23ba49faeee8fd.squirrel@sq.gransy.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-performance |
On 28 Únor 2012, 14:08, Claudio Freire wrote:
> On Tue, Feb 28, 2012 at 5:30 AM, Stefan Keller <sfkeller(at)gmail(dot)com> wrote:
>>
>> But what I'm finally after is a solution, where records don't get
>> pushed back to disk a.s.a.p. but rather got hold in memory as long as
>> possible assuming that there is enough memory.
>
> fsync = off ?
I don't think this is a viable idea, unless you don't care about the data.
Moreover, "fsyn=off" does not mean "not writing" and writing does not mean
"removing from shared buffers". A page written/fsynced during a checkpoint
may stay in shared buffers.
AFAIK the pages are not removed from shared buffers without a reason. So a
dirty buffer is written to a disk (because it needs to, to keep ACID) but
stays in shared buffers as "clean" (unless it was written by a backend,
which means there's not enough memory).
Tomas
From | Date | Subject | |
---|---|---|---|
Next Message | Claudio Freire | 2012-02-28 13:52:28 | Re: [PERFORM] Re: [PERFORM] Re: 回复: [PERFORM] PG as in-memory db? How to warm up and re-populate buffers? How to read in all tuples into memory? |
Previous Message | Claudio Freire | 2012-02-28 13:08:25 | Re: [PERFORM] Re: 回复: [PERFORM] PG as in-memory db? How to warm up and re-populate buffers? How to read in all tuples into memory? |