Re: SSI SLRU strategy choices

From: "Kevin Grittner" <Kevin(dot)Grittner(at)wicourts(dot)gov>
To: "Alvaro Herrera" <alvherre(at)commandprompt(dot)com>
Cc: "Heikki Linnakangas" <heikki(dot)linnakangas(at)enterprisedb(dot)com>, "pgsql-hackers" <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: SSI SLRU strategy choices
Date: 2010-12-29 20:20:40
Message-ID: 4D1B43B80200002500038D8D@gw.wicourts.gov
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

Alvaro Herrera <alvherre(at)commandprompt(dot)com> wrote:

> If these limitations become a problem, you can always change them.
> A couple of zeroes at the start of the pg_clog filenames aren't
> going to bother anyone, I don't think. Not so sure about your new
> proposed design's space usage.

I guess that's a call the community can make now -- if a
serializable transaction which is not flagged as read only remains
open long enough for over a billion other transactions to commit, is
it OK for the old transaction to be automatically canceled? Is it
worth messing with the SLRU limits to double that?

Beyond a certain point you have transaction ID wrap-around, so at
that point this would be the least of your troubles -- canceling
the old transaction might even be helpful. I thought that was at 2
billion, but Heikki was saying it's at 1 billion in an earlier post.

-Kevin

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Tom Lane 2010-12-29 20:23:42 Re: Extensions, patch v16
Previous Message Bruce Momjian 2010-12-29 20:18:48 Re: Anyone for SSDs?