| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Bruce Momjian <bruce(at)momjian(dot)us> |
| Cc: | Gregory Stark <stark(at)enterprisedb(dot)com>, Simon Riggs <simon(at)2ndquadrant(dot)com>, Heikki Linnakangas <heikki(at)enterprisedb(dot)com>, PostgreSQL-patches <pgsql-patches(at)postgresql(dot)org> |
| Subject: | Re: Improvement of procArray.xmin for VACUUM |
| Date: | 2007-03-27 01:59:35 |
| Message-ID: | 9788.1174960775@sss.pgh.pa.us |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-patches |
Bruce Momjian <bruce(at)momjian(dot)us> writes:
> Gregory Stark wrote:
>> I have a question about what would happen for a transaction running a command
>> like COPY FROM. Is it possible it would manage to arrange to have no live
>> snapshots at all? So it would have no impact on concurrent VACUUMs? What about
>> something running a large pg_restore?
> Interesting idea.
Indeed. Currently, COPY forcibly sets a snapshot on the off chance
something will use it, but I could certainly see making that happen
"lazily", ie not at all in the simple case.
pg_restore is probably a lost cause, at least if you are running it
in single-transaction mode. I guess there'd be tradeoffs as to whether
to do that or not ...
regards, tom lane
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Tom Lane | 2007-03-27 02:03:01 | Re: patch adding new regexp functions |
| Previous Message | Bruce Momjian | 2007-03-27 01:55:44 | Re: --enable-xml instead of --with-libxml? |