| From: | Martijn van Oosterhout <kleptog(at)svana(dot)org> |
|---|---|
| To: | Bo Lorentsen <bl(at)netgroup(dot)dk> |
| Cc: | "pgsql-general postgresql(dot)org" <pgsql-general(at)postgresql(dot)org> |
| Subject: | Re: OID Usage |
| Date: | 2005-01-15 20:23:31 |
| Message-ID: | 20050115202325.GC22775@svana.org |
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| Lists: | pgsql-general |
On Sat, Jan 15, 2005 at 07:10:48PM +0100, Bo Lorentsen wrote:
> >Using the CTID, which locates the physical tuple as (block,num). When
> >you update a tuple, or vacuum moves it its CTID will change, so it's
> >not terribly useful from a user's point of view.
> >
> Hmm, so a data row update also update the CTID in all indexes, too. I
> see what you mean !
Not quite, a single index entry needs to point to any number of rows,
which may or may not be visible depending on your transaction, so they
form a sort of linked list. But indeed, not terribly useful for your
purpose...
Hope this helps,
--
Martijn van Oosterhout <kleptog(at)svana(dot)org> http://svana.org/kleptog/
> Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a
> tool for doing 5% of the work and then sitting around waiting for someone
> else to do the other 95% so you can sue them.
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