Re: On partitioning

Heikki Linnakangas <hlinnakangas@vmware.com>

From: Heikki Linnakangas <hlinnakangas@vmware.com>
To: Tom Lane <tgl@sss.pgh.pa.us>, Greg Stark <stark@mit.edu>
Cc: Alvaro Herrera <alvherre@2ndquadrant.com>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2014-09-01T16:12:17Z
Lists: pgsql-hackers
On 09/01/2014 06:59 PM, Tom Lane wrote:
> Greg Stark <stark@mit.edu> writes:
>> On Sun, Aug 31, 2014 at 9:03 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>>> Aside from costing planning time, most likely that would forever prevent
>>> us from pushing some types of intelligence about partitioning into the
>>> executor.
>
>> How would it affect this calculus if there were partitioned indexes
>> which were created on the overall table and guaranteed to exist on
>> each partition that the planner could use -- and then possibly also
>> per-partition indexes that might exist in addition to those?
>
> That doesn't actually fix the planning-time issue at all.  Either the
> planner considers each partition individually to create a custom plan
> for it, or it doesn't.

Hmm. Couldn't you plan together all partitions that do have the same 
indexes? In other words, create a custom plan for each group of 
partitions, rather than each partition?

- Heikki