From: | Andres Freund <andres(at)anarazel(dot)de> |
---|---|
To: | Robert Haas <robertmhaas(at)gmail(dot)com> |
Cc: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Alvaro Herrera <alvherre(at)2ndquadrant(dot)com>, James Coleman <jtc331(at)gmail(dot)com>, pgsql-hackers <pgsql-hackers(at)lists(dot)postgresql(dot)org>, Simon Riggs <simon(at)2ndquadrant(dot)com> |
Subject: | Re: PROC_IN_ANALYZE stillborn 13 years ago |
Date: | 2020-08-06 21:26:32 |
Message-ID: | 20200806212632.r7zl7fvu2s737lsx@alap3.anarazel.de |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
Hi,
On 2020-08-06 14:48:52 -0400, Robert Haas wrote:
> On Thu, Aug 6, 2020 at 2:37 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> > +1 for removal. It's not clear to me that we'd ever put it back.
> > Long-running ANALYZE snapshots are indeed a problem, but Simon's proposal
> > upthread to just take a new one every so often seems like a much cleaner
> > and simpler answer than having onlookers assume that it's safe to ignore
> > ANALYZE processes. (Given that ANALYZE can invoke user-defined functions,
> > and can be invoked from inside user transactions, any such assumption
> > seems horribly dangerous.
>
> Not to get too far from the proposal on the table of just removing
> something that's been unused for a really long time, which stands on
> its own merits, but if a particular ANALYZE doesn't invoke any
> user-defined functions and isn't run inside a transaction, could we
> skip acquiring a snapshot altogether? That's an extremely common case,
> though by no means universal.
I don't think so, at least not in very common situations. E.g. as long
as there's a toast table we need to hold a snapshot to ensure that we
don't get failures looking up toasted datums. IIRC there were some other
similar issues that I can't quite recall right now.
Greetings,
Andres Freund
From | Date | Subject | |
---|---|---|---|
Next Message | Peter Geoghegan | 2020-08-06 21:33:02 | Re: amcheck verification for GiST and GIN |
Previous Message | Jonathan S. Katz | 2020-08-06 21:04:35 | Re: PostgreSQL 13 Beta 3 Release Date (+ Update Release) |