Re: - Mailing list pgsql-performance

From Matt Casters
Subject Re:
Date
Msg-id 12670.193.190.212.113.1106297446.squirrel@193.190.212.113
Whole thread Raw
In response to Re:  (Bruno Wolff III <bruno@wolff.to>)
Responses Re:
List pgsql-performance
> On Thu, Jan 20, 2005 at 11:31:29 -0500,
>   Alex Turner <armtuk@gmail.com> wrote:
>> I am curious - I wasn't aware that postgresql supported partitioned tables,
>> Could someone point me to the docs on this.
>
> Some people have been doing it using a union view. There isn't actually
> a partition feature.
>
>

Actually, there is.  If found this example on pgsql-performance:

>>   CREATE TABLE super_foo ( partition NUMERIC, bar NUMERIC );
>>   ANALYZE super_foo ;
>>
>>   CREATE TABLE sub_foo1 () INHERITS ( super_foo );
>>   INSERT INTO sub_foo1 VALUES ( 1, 1 );
>>   -- repeat insert until sub_foo1 has 1,000,000 rows
>>   CREATE INDEX idx_subfoo1_partition ON sub_foo1 ( partition );
>>   ANALYZE sub_foo1 ;
>>
>>   CREATE TABLE sub_foo2 () INHERITS ( super_foo );
>>   INSERT INTO sub_foo2 VALUES ( 2, 1 );
>>   -- repeat insert until sub_foo2 has 1,000,000 rows
>>   CREATE INDEX idx_subfoo2_partition ON sub_foo2 ( partition );
>>   ANALYZE sub_foo2 ;
>>

I think that in certain cases this system even beats Oracle as it stores less information in the
table partitions. (and in doing so is causing less disk IO)
BTW, internally, Oracle sees partitions as tables too.  Even the "Union all" system that MS SQL
Server uses works fine as long as the optimiser supports it to prune correctly.

Cheers,

Matt
------
Matt Casters <matt.casters@ibridge.be>
i-Bridge bvba, http://www.kettle.be
Fonteinstraat 70, 9400 Okegem, Belgium
Phone +32 (0) 486/97.29.37



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