| From: | Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> |
|---|---|
| To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Cc: | Hannu Krosing <hannu(at)skype(dot)net>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: Question about explain of index scan |
| Date: | 2005-09-04 22:37:14 |
| Message-ID: | 20050904223714.GB14515@surnet.cl |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On Sun, Sep 04, 2005 at 06:21:51PM -0400, Tom Lane wrote:
> XID comparison works OK as long as you make sure that all the XIDs
> extant in the system at any one time are within +/- 2 billion of each
> other, and so transitivity does hold within that subset. The problem
> with a btree is that upper-level tree nodes are likely to contain page
> boundary keys copied from data that vanished some time ago from the
> underlying table.
So there would be no problem if a REINDEX was forced every two billion
transactions, right? (A bit less, I think.)
--
Alvaro Herrera -- Valdivia, Chile Architect, www.EnterpriseDB.com
"Oh, great altar of passive entertainment, bestow upon me thy discordant images
at such speed as to render linear thought impossible" (Calvin a la TV)
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Hannu Krosing | 2005-09-04 23:11:38 | Re: Question about explain of index scan |
| Previous Message | Tom Lane | 2005-09-04 22:21:51 | Re: Question about explain of index scan |