From: | Alvaro Herrera <alvherre(at)surnet(dot)cl> |
---|---|
To: | Josh Berkus <josh(at)agliodbs(dot)com> |
Cc: | pgsql-hackers(at)postgresql(dot)org |
Subject: | Re: query plan ignoring check constraints |
Date: | 2005-06-20 18:40:07 |
Message-ID: | 20050620184007.GE7864@surnet.cl |
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Thread: | |
Lists: | pgsql-hackers |
On Mon, Jun 20, 2005 at 10:35:24AM -0700, Josh Berkus wrote:
> Rohit,
>
> > Now, when I do a select on the basetable with a range of ids, it looks up
> > each subtable that inherits from the base table and using an indexed scan
> > searches for values in the range. It does it even for subtables whose check
> > constraint completely rules out the possibility of it containing any such
> > row . Should not check constraint act as the first filter? The index should
> > ideally be scanned only when the check constraint is passed by the search
> > criteria but surprisingly it did not happen. The explain analyze showed
> > cost for index scans of subtables that cannot contain rows matching the
> > search criteria.
>
> This is called "range partitioning". We're working on it. You're welcome to
> join the Bizgres project where most of the discussion on this feature takes
> place:
Why are you discussing development there? I can see in the archives
that people are talking about changing page format, semantics of tuple
info bits, and it's not getting to some "people that matters."
--
Alvaro Herrera (<alvherre[a]surnet.cl>)
La web junta la gente porque no importa que clase de mutante sexual seas,
tienes millones de posibles parejas. Pon "buscar gente que tengan sexo con
ciervos incendiándose", y el computador dirá "especifique el tipo de ciervo"
(Jason Alexander)
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