| From: | Jan Wieck <JanWieck(at)Yahoo(dot)com> |
|---|---|
| To: | Dimitri Fontaine <dfontaine(at)hi-media(dot)com> |
| Cc: | Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>, Greg Stark <gsstark(at)mit(dot)edu>, PostgreSQL Development <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: Exposing the Xact commit order to the user |
| Date: | 2010-05-26 20:36:43 |
| Message-ID: | 4BFD865B.90406@Yahoo.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On 5/26/2010 4:11 PM, Dimitri Fontaine wrote:
> So even ordering the txid and txid_snapshots with respect to WAL commit
> time (LSN) won't be the whole story, for any given transaction
> containing more than one event we also need to have them in order. I
> know Jan didn't forget about it so it must either be in the proposal or
> easily derived, too tired to recheck.
No, that detail is actually not explained in the proposal. When applying
all changes in transaction commit order, there is no need for a global
sequence. A local counter per backend is sufficient because the total
order of <xact-commit-order>, <local-xact-seq> yields a similarly
agreeable order of actions.
Jan
--
Anyone who trades liberty for security deserves neither
liberty nor security. -- Benjamin Franklin
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Peter Eisentraut | 2010-05-26 20:44:30 | functional call named notation clashes with SQL feature |
| Previous Message | Kevin Grittner | 2010-05-26 20:34:29 | Re: Exposing the Xact commit order to the user |