From: | Bruce Momjian <bruce(at)momjian(dot)us> |
---|---|
To: | Gregory Stark <stark(at)enterprisedb(dot)com> |
Cc: | PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>, Pavan Deolasee <pavan(dot)deolasee(at)enterprisedb(dot)com>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Simon Riggs <simon(at)2ndquadrant(dot)com> |
Subject: | Re: CREATE INDEX and HOT - revised design |
Date: | 2007-03-21 16:35:38 |
Message-ID: | 200703211635.l2LGZc924380@momjian.us |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
As stated in later email, I think we should focus on the xid idea
because it is more flexible.
---------------------------------------------------------------------------
Gregory Stark wrote:
>
> "Bruce Momjian" <bruce(at)momjian(dot)us> writes:
>
> > We also add a boolean to pg_class to indicate no new HOT chains should be
> > created and set that to false once the new index is created.
>
> Since we have all the index info in the relcache we could just skim through
> all the indexes when we build the relcache and decide then whether we're
> allowed to do HOT updates. That avoids problems if we crash while HOT updates
> are disabled.
>
> I think we need to think harder about exactly what test we would perform
> against this xid to determine the two relevant tests,
>
> a) whether to prohibit HOT updates (because the index is "too new")
>
> b) whether to ignore HOT update chains when we use the index (because it's
> "too new" and any HOT update chains predate it).
>
> I fear it may imply that we have to keep performing cold updates until the
> first vacuum after the xid expires.
>
> --
> Gregory Stark
> EnterpriseDB http://www.enterprisedb.com
>
> ---------------------------(end of broadcast)---------------------------
> TIP 1: if posting/reading through Usenet, please send an appropriate
> subscribe-nomail command to majordomo(at)postgresql(dot)org so that your
> message can get through to the mailing list cleanly
--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://www.enterprisedb.com
+ If your life is a hard drive, Christ can be your backup. +
From | Date | Subject | |
---|---|---|---|
Next Message | Chris Browne | 2007-03-21 16:37:36 | TOASTing smaller things |
Previous Message | Bruce Momjian | 2007-03-21 16:34:22 | Re: CREATE INDEX and HOT - revised design |