From:
Stephen Frost <sfrost(at)snowman(dot)net>
To:
Robert Haas <robertmhaas(at)gmail(dot)com>
Cc:
Simon Riggs <simon(at)2ndquadrant(dot)com>,Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>,Greg Smith <greg(at)2ndquadrant(dot)com>,Marko Tiikkaja <marko(dot)tiikkaja(at)cs(dot)helsinki(dot)fi>,Boxuan Zhai <bxzhai2010(at)gmail(dot)com>, pgsql-hackers(at)postgresql(dot)org
Subject:
Re: Re: new patch of MERGE (merge_204) & a question
about duplicated ctid
Date:
2011-01-03 15:56:27
Message-ID:
20110103155627.GI4933@tamriel.snowman.net (view raw or flat )
Thread:
2010-12-04 13:27:52 from Boxuan Zhai <bxzhai2010(at)gmail(dot)com>
2010-12-05 14:12:09 from David Fetter <david(at)fetter(dot)org>
2010-12-05 18:12:57 from Greg Smith <greg(at)2ndquadrant(dot)com>
2010-12-06 13:17:46 from Boxuan Zhai <bxzhai2010(at)gmail(dot)com>
2010-12-07 17:53:49 from "Erik Rijkers" <er(at)xs4all(dot)nl>
2010-12-29 11:51:42 from Greg Smith <greg(at)2ndquadrant(dot)com>
2010-12-29 12:14:32 from Greg Smith <greg(at)2ndquadrant(dot)com>
2010-12-29 12:43:55 from Marko Tiikkaja <marko(dot)tiikkaja(at)cs(dot)helsinki(dot)fi>
2010-12-30 02:39:38 from Greg Smith <greg(at)2ndquadrant(dot)com>
2010-12-30 02:45:31 from Marko Tiikkaja <marko(dot)tiikkaja(at)cs(dot)helsinki(dot)fi>
2010-12-30 04:17:09 from Robert Haas <robertmhaas(at)gmail(dot)com>
2010-12-30 07:02:51 from Greg Smith <greg(at)2ndquadrant(dot)com>
2010-12-30 11:46:58 from Marko Tiikkaja <marko(dot)tiikkaja(at)cs(dot)helsinki(dot)fi>
2011-01-03 06:53:58 from Greg Smith <greg(at)2ndquadrant(dot)com>
2011-01-03 09:37:56 from Simon Riggs <simon(at)2ndQuadrant(dot)com>
2011-01-03 13:12:10 from Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
2011-01-03 13:35:53 from Simon Riggs <simon(at)2ndQuadrant(dot)com>
2011-01-03 14:57:27 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-03 15:56:27 from Stephen Frost <sfrost(at)snowman(dot)net>
2011-01-03 15:58:44 from Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
2011-01-03 16:02:26 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-03 16:08:51 from Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
2011-01-03 16:21:15 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-03 16:36:25 from Florian Pflug <fgp(at)phlo(dot)org>
2011-01-03 17:09:32 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-03 16:29:19 from Simon Riggs <simon(at)2ndQuadrant(dot)com>
2011-01-03 16:35:18 from Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
2011-01-03 16:49:23 from Simon Riggs <simon(at)2ndQuadrant(dot)com>
2011-01-03 17:01:00 from Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
2011-01-03 17:48:57 from Simon Riggs <simon(at)2ndQuadrant(dot)com>
2011-01-03 17:50:39 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-03 18:18:57 from "Kevin Grittner" <Kevin(dot)Grittner(at)wicourts(dot)gov>
2011-01-03 18:34:57 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-03 19:01:20 from "Kevin Grittner" <Kevin(dot)Grittner(at)wicourts(dot)gov>
2011-01-03 19:11:23 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-04 10:11:59 from Greg Smith <greg(at)2ndquadrant(dot)com>
2011-01-03 16:06:15 from Andrew Dunstan <andrew(at)dunslane(dot)net>
2011-01-04 09:44:32 from Greg Smith <greg(at)2ndquadrant(dot)com>
2011-01-04 16:27:08 from David Fetter <david(at)fetter(dot)org>
2011-01-04 17:02:54 from Marko Tiikkaja <marko(dot)tiikkaja(at)cs(dot)helsinki(dot)fi>
2011-01-04 17:09:45 from David Fetter <david(at)fetter(dot)org>
2011-01-05 02:27:10 from Greg Smith <greg(at)2ndquadrant(dot)com>
2011-01-05 07:09:57 from David Fetter <david(at)fetter(dot)org>
2011-01-18 18:21:18 from Greg Smith <greg(at)2ndquadrant(dot)com>
2010-12-30 14:35:38 from Andrew Dunstan <andrew(at)dunslane(dot)net>
Lists:
pgsql-hackers
* Robert Haas (robertmhaas(at)gmail(dot)com) wrote:
> Like Heikki, I'd rather have the feature without a workaround for the
> concurrency issues than no feature.
I'm still trying to figure out the problem with having the table-level
lock, unless we really think people will be doing concurrent MERGE's
where they won't overlap..? I'm also a bit nervous about if the result
of concurrent MERGE's would actually be correct if we're not taking a
bigger lock than row-level (I assume we're taking row-level locks as it
goes through..).
In general, I also thought/expected to have some kind of UPSERT type
capability with our initial MERGE support, even if it requires a big
lock and won't operate concurrently, etc.
> But I have to admit that the
> discussion we've had thus far gives me very little confidence that
> this code is anywhere close to bug-free. So I think we're going to
> end up punting it to 9.2 not so much because it's not concurrency-safe
> as because it doesn't work.
That's certainly a concern. :/
Stephen
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Next :From: Heikki LinnakangasDate: 2011-01-03 15:58:44Subject : Re: Re: new patch of MERGE (merge_204) & a question about
duplicated ctidPrevious :From : Robert HaasDate : 2011-01-03 15:52:20Subject : Re: Scanning pg_tablespace from walsender
