Re: Constraint Exclusion (Partitioning) - Mailing list pgsql-hackers

From Jochem van Dieten
Subject Re: Constraint Exclusion (Partitioning)
Date
Msg-id f96a9b830507051342aa70c8c@mail.gmail.com
Whole thread Raw
In response to Constraint Exclusion (Partitioning)  (Simon Riggs <simon@2ndquadrant.com>)
List pgsql-hackers
I can't believe I am the first one to respond to this :)

On 6/27/05, Simon Riggs wrote:
> On Mon, 2005-06-27 at 01:41 +0100, Simon Riggs wrote:
>>
>> The main purpose of this feature is to reduce access time against large
>> tables that have been split into partitions by using the PostgreSQL
>> inheritance facility. It has been written in a very generic way allowing
>> a whole range of applications.
>>
>> If
>>       a) a table is part of an inheritance set
>>       b) the table has check constraints defined upon it
>>       c) enable_constraint_exclusion = true

>> Main questions:
>> 2. Should this feature be available for all queries or just inherited
>> relations?

I think this feature would be useful as well for home-brewn
partitioning implementations based on a view of unions instead of
inheritance.
But I have to admit to having some doubts about the tradeoff in CPU
cycles for this very specific case: if somebody wants to benefit from
this new feature he has to upgrade to 8.2 anyway and changing from a
view to inheritance is not that drastic.

Jochem


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