Re: SQL/MED - core functionality

Excerpts from David Fetter's message of mié dic 22 12:36:10 -0300 2010:
> On Wed, Dec 22, 2010 at 03:00:16PM +0000, Simon Riggs wrote:
> > On Wed, 2010-12-22 at 09:03 -0500, Andrew Dunstan wrote:

> > > Quite apart from other reasons, such as possible ephemerality of
> > > the data, the difficulty of taking a reasonable random sample from
> > > an arbitrary foreign data source seems substantial, and we surely
> > > don't want ANALYSE to have to run a full sequential scan of a
> > > foreign data source.
> > 
> > I think we need something that estimates the size of a table, at
> > least, otherwise queries will be completely un-optimised.
> 
> The estimated size for a lot of things--streams of data, for
> example--is infinity.  I suppose that's a good default for some cases.

Since we don't have streaming queries, this would seem rather pointless ...
Surely the FDW must be able to limit the resultset somehow.

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Álvaro Herrera <alvherre@commandprompt.com>
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