Re: effective SELECT from child tables

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От Martijn van Oosterhout
Тема Re: effective SELECT from child tables
Дата
Msg-id 20051001143541.GD13830@svana.org
обсуждение исходный текст
Ответ на Re: effective SELECT from child tables  (mark@mark.mielke.cc)
Ответы Re: effective SELECT from child tables  ("Jim C. Nasby" <jnasby@pervasive.com>)
Re: effective SELECT from child tables  (mark@mark.mielke.cc)
Re: effective SELECT from child tables  (mark@mark.mielke.cc)
Список pgsql-hackers
On Sat, Oct 01, 2005 at 10:05:22AM -0400, mark@mark.mielke.cc wrote:
> It has the 'side or additional benefit' being requested here. The ability
> to filter the child table by some attribute. For example, if the child
> tables are used for partitioning, and the attribute were to keep a date
> range, the field restriction optimization could be used to automatically
> determine the set of tables to use for the date range specified. With
> such a change, it would even work automatically if the date ranges
> overlapped for some reason. Selecting a table name by date is hacky. This
> sort of solution would be a general solution to the problem.

This is what "Constraint Exclusion" does. It uses CHECK constraints on
a table to filter out tables that obviously don't apply to a query.
It's just the the specific case of "tableoid = XXX" is not supported
right now.

Have a nice day,
--
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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