| From: | Robert Haas <robertmhaas(at)gmail(dot)com> |
|---|---|
| To: | Andres Freund <andres(at)anarazel(dot)de> |
| Cc: | Ivan Kartyshov <i(dot)kartyshov(at)postgrespro(dot)ru>, "pgsql-hackers(at)postgresql(dot)org" <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: less expensive pg_buffercache on big shmem |
| Date: | 2016-09-02 09:01:28 |
| Message-ID: | CA+TgmobrEja6V3Jgw+KJR1um7VNT2Mup=vrrJwnvWiFmM2vjNw@mail.gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On Fri, Sep 2, 2016 at 8:49 AM, Andres Freund <andres(at)anarazel(dot)de> wrote:
> On 2016-09-02 08:31:42 +0530, Robert Haas wrote:
>> I wonder whether we ought to just switch from the consistent method to
>> the semiconsistent method and call it good.
>
> +1. I think, before long, we're going to have to switch away from having
> locks & partitions in the first place. So I don't see a problem relaxing
> this. It's not like that consistency really buys you anything... I'd
> even consider not using any locks.
I think we certainly want to lock the buffer header, because otherwise
we might get a torn read of the buffer tag, which doesn't seem good.
But it's not obvious to me that there's any point in taking the lock
on the buffer mapping partition; I'm thinking that doesn't really do
anything unless we lock them all, and we all seem to agree that's
going too far.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Christoph Berg | 2016-09-02 09:05:08 | Re: [PATCH] COPY vs \copy HINT |
| Previous Message | Heikki Linnakangas | 2016-09-02 08:52:49 | Re: Optimizing numeric SUM() aggregate |