From: | Alexander Korotkov <a(dot)korotkov(at)postgrespro(dot)ru> |
---|---|
To: | Andres Freund <andres(at)anarazel(dot)de> |
Cc: | pgsql-committers <pgsql-committers(at)lists(dot)postgresql(dot)org> |
Subject: | Re: pgsql: tableam: Add tuple_{insert, delete, update, lock} and use. |
Date: | 2019-03-24 18:17:15 |
Message-ID: | CAPpHfdsEi8DuUyy=aC=CenmD0H1Azx_vvytDzNQU6XHOWthM3A@mail.gmail.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-committers |
Great work, thank you very much!
On Sun, Mar 24, 2019 at 6:02 AM Andres Freund <andres(at)anarazel(dot)de> wrote:
> Previously both delete/update/lock call-sites and the EPQ mechanism had
> to have awareness of the specific tuple format to be able to fetch the
> latest version of a tuple. Obviously that needs to be abstracted
> away. To do so, move the logic that find the latest row version into
> the AM. lock_tuple has a new flag argument,
> TUPLE_LOCK_FLAG_FIND_LAST_VERSION, that forces it to lock the last
> version, rather than the current one. It'd have been possible to do
> so via a separate callback as well, but finding the last version
> usually also necessitates locking the newest version, making it
> sensible to combine the two. This replaces the previous use of
> EvalPlanQualFetch(). Additionally HeapTupleUpdated, which previously
> signaled either a concurrent update or delete, is now split into two,
> to avoid callers needing AM specific knowledge to differentiate.
BTW, given your skepticism during PGCon 2018 discussions, I didn't
expect my lock tuple patch [1] to get in. But if it finally got in,
I've expected to be listed as author...
------
Alexander Korotkov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company
From | Date | Subject | |
---|---|---|---|
Next Message | Andres Freund | 2019-03-24 18:22:47 | Re: pgsql: tableam: Add tuple_{insert, delete, update, lock} and use. |
Previous Message | Tom Lane | 2019-03-24 18:02:24 | Re: pgsql: Make heap TID a tiebreaker nbtree index column. |