Re: On partitioning - Mailing list pgsql-hackers

From Robert Haas
Subject Re: On partitioning
Date
Msg-id CA+TgmoYk9aU44Z5YRWoV2V9raj=HMbJBfORYr9GzF4vShsGvDA@mail.gmail.com
Whole thread Raw
In response to Re: On partitioning  (Amit Kapila <amit.kapila16@gmail.com>)
Responses Re: On partitioning  ("Amit Langote" <Langote_Amit_f8@lab.ntt.co.jp>)
List pgsql-hackers
On Sat, Dec 6, 2014 at 2:59 AM, Amit Kapila <amit.kapila16@gmail.com> wrote:
>> I guess you could list or hash partition on multiple columns, too.
>
> How would you distinguish values in list partition for multiple
> columns? I mean for range partition, we are sure there will
> be either one value for each column, but for list it could
> be multiple and not fixed for each partition, so I think it will not
> be easy to support the multicolumn partition key for list
> partitions.

I don't understand.  If you want to range partition on columns (a, b),
you say that, say, tuples with (a, b) values less than (100, 200) go
here and the rest go elsewhere.  For list partitioning, you say that,
say, tuples with (a, b) values of EXACTLY (100, 200) go here and the
rest go elsewhere.  I'm not sure how useful that is but it's not
illogical.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company



pgsql-hackers by date:

Previous
From: Josh Berkus
Date:
Subject: Re: On partitioning
Next
From: Robert Haas
Date:
Subject: Re: On partitioning