Re: Rethinking representation of sort/hash semantics in queries and plans

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Dimitri Fontaine <dimitri@2ndQuadrant.fr>
Cc: pgsql-hackers@postgresql.org
Date: 2010-11-28T21:20:19Z
Lists: pgsql-hackers
Dimitri Fontaine <dimitri@2ndQuadrant.fr> writes:
> Tom Lane <tgl@sss.pgh.pa.us> writes:
>> So to fix these problems we'd need to replace sort operator OIDs in
>> SortGroupClause and plan nodes with those three items.  Obviously, this
>> would be slightly bulkier, but the extra cost added to copying parse and
>> plan trees should be tiny compared to the avoided syscache lookups.

> My understanding is that opfamily+datatype gives an opclass. What about
> storing the opclass OID there?

Then you'd just need to look up the opfamily again.  Opclasses are too
small a division to be useful.

			regards, tom lane