Horton

Re: Allowing extensions to supply operator-/function-specific info

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

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Paul Ramsey <pramsey@cleverelephant.ca>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2019-02-26T00:09:11Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Allow extensions to generate lossy index conditions.

  2. Build out the planner support function infrastructure.

  3. Create the infrastructure for planner support functions.

  4. Disable transforms that replaced AT TIME ZONE with RelabelType.

Paul Ramsey <pramsey@cleverelephant.ca> writes:
> On Mon, Feb 25, 2019 at 3:01 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> It's whichever one the index column's opclass belongs to.  Basically what
>> you're trying to do here is verify whether the index will support the
>> optimization you want to perform.

> * If I have tbl1.geom
> * and I have built two indexes on it, a btree_geometry_ops and a
> gist_geometry_ops_2d, and
> * and SupportRequestIndexCondition.opfamily returns me the btree family
> * and I look and see, "damn there is no && operator in there"
> * am I SOL, even though an appropriate index does exist?

No.  If there are two indexes matching your function's argument, you'll
get a separate call for each index.  The support function is only
responsible for thinking about one index at a time and seeing if it
can be used.  If more than one can be used, figuring out which
one is better is done by later cost comparisons.

			regards, tom lane