Re: OID Usage - Mailing list pgsql-general

From Martijn van Oosterhout
Subject Re: OID Usage
Date
Msg-id 20050115202325.GC22775@svana.org
Whole thread Raw
In response to Re: OID Usage  (Bo Lorentsen <bl@netgroup.dk>)
Responses Re: OID Usage  (Tom Lane <tgl@sss.pgh.pa.us>)
Re: OID Usage  (Bo Lorentsen <bl@netgroup.dk>)
List 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@svana.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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