| From: | "Zeugswetter Andreas ADI SD" <ZeugswetterA(at)spardat(dot)at> |
|---|---|
| To: | "Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us>, "Alvaro Herrera" <alvherre(at)commandprompt(dot)com> |
| Cc: | "Simon Riggs" <simon(at)2ndquadrant(dot)com>, <pgsql-hackers(at)postgreSQL(dot)org> |
| Subject: | Re: FOR SHARE vs FOR UPDATE locks |
| Date: | 2006-12-01 15:45:00 |
| Message-ID: | E1539E0ED7043848906A8FF995BDA579018FE8F2@m0143.s-mxs.net |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-docs pgsql-hackers |
> > I'm not sure we can use the simple "raise an ERROR" answer though,
> > because for users that would be a regression.
>
> I've reconsidered the idea of upgrading the outer xact's shared lock
to
> exclusive: at first I thought that would be hard to implement
correctly,
> but now I realize it's easy. Just re-use the XID that's in the
multixact
> as the one to store as the exclusive locker, instead of storing our
> current subxact XID. In some cases this will be a subcommitted XID of
> the current subxact or a parent, but the locking semantics are the
same,
> and even though we think such an XID is finished everyone else will
see
> it as still live so the appearance of its XID in an XMAX field
shouldn't
> be an issue.
fwiw, I think that is good.
Andreas
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Heikki Linnakangas | 2006-12-01 16:55:56 | Re: FOR SHARE vs FOR UPDATE locks |
| Previous Message | Tom Lane | 2006-12-01 15:12:06 | Re: FOR SHARE vs FOR UPDATE locks |
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Heikki Linnakangas | 2006-12-01 16:55:56 | Re: FOR SHARE vs FOR UPDATE locks |
| Previous Message | Leandro Lucarella | 2006-12-01 15:44:22 | Re: Keep-alive support |