Обсуждение: BTrees with record numbers

Is it possible for Postgres Btrees to support access by logical row number ?
If not available is ti a huge job to support for sombebody willing to have a go ?

On 27 Feb 2004, Chad wrote:

> Is it possible for Postgres Btrees to support access by logical row number ?
> If not available is ti a huge job to support for sombebody willing to have a go ?

Are talking about logical row operators as maintained by your own code 
outside the database, or having postgresql suddenly start maintaining 
logical row numbers?  I doubt postgresql will ever have built in logical 
row numbers because maintaining them in a materialized way is quite 
expensive.

On the other hand, if you just need logical row numbers for a one off 
thing, you can do this:

create temp sequence judy;
select *, nextval('judy') from mytable;

Chad kirjutas R, 27.02.2004 kell 14:53:
> Is it possible for Postgres Btrees to support access by logical row number ?

WHat do you mean by "logical row number" ?

------------
Hannu

Guys, thanks fo rthe replies.
I'm talking about the stuff that the other poster (cant see his name
right now, sorry) doubts will ever be in postgres. ie you can seek to
anywhere in the Btree using a row offset as a "search" key.

I'd love to hear why this would be hard to support in a materialized
view. Could you explain that ? Berkeley DB supports it.

Chad

hannu@tm.ee (Hannu Krosing) wrote in message news:<1078220441.2621.0.camel@fuji.krosing.net>...
> Chad kirjutas R, 27.02.2004 kell 14:53:
> > Is it possible for Postgres Btrees to support access by logical row number ?
> 
> WHat do you mean by "logical row number" ?
> 
> ------------
> Hannu
> 
> 
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