Re: Review: Fix snapshot taking inconsistencies
Robert Haas <robertmhaas@gmail.com>
From: Robert Haas <robertmhaas@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Marko Tiikkaja <marko.tiikkaja@cs.helsinki.fi>, Steve Singer <ssinger_pg@sympatico.ca>, pgsql-hackers@postgresql.org, Alvaro Herrera <alvherre@commandprompt.com>
Date: 2011-02-28T19:14:59Z
Lists: pgsql-hackers
On Mon, Feb 28, 2011 at 2:01 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote: > Robert Haas <robertmhaas@gmail.com> writes: >> On Mon, Feb 28, 2011 at 1:45 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote: >>> I'm afraid that the goals of this patch might be similarly obsolete. > >> No, I don't think so. IIUC, the problem is that EXPLAIN ANALYZE runs >> the rewrite products with different snapshot handling than the regular >> execution path. > > Possibly, but it's not clear to me that this patch fixes that. > As I said, it's no longer obvious what the patch means to do, and I'd > like a clear statement of that. Fair enough. I assume Marko will provide that shortly. I believe the consensus was to make the regular case behave like EXPLAIN ANALYZE rather than the other way around... >> So in theory you could turn on auto_explain and have >> the semantics of your queries change. That would be Bad. > > That's just FUD. auto_explain doesn't run EXPLAIN ANALYZE. Oh, woops. I stand corrected. But I guess the query might behave differently with and without EXPLAIN ANALYZE? -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company