From: Tom Lane <tgl@sss.pgh.pa.us>
To: Jeff Janes <jeff.janes@gmail.com>
cc: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>,
        Dmitry Dolgov <9erthalion6@gmail.com>,
        Pavel Stehule <pavel.stehule@gmail.com>,
        PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: why partition pruning doesn't work?
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Comments: In-reply-to Jeff Janes <jeff.janes@gmail.com>
	message dated "Sat, 02 Jun 2018 17:16:51 -0400"
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Date: Sat, 02 Jun 2018 18:06:10 -0400
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Jeff Janes <jeff.janes@gmail.com> writes:
> On Fri, Jun 1, 2018 at 11:53 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> It's worth questioning whether this is a bug fix or an improvement.
>> If the latter, it probably ought to wait for v12.

> If explaining the change requires reference to tokens from the source code,
> rather than something an end user could understand, I'd argue it is a bug
> fix rather than an improvement.

Well, the difference between volatile, stable and immutable functions is
well-documented, so I don't think that's a great argument.  If there's
some aspect of this behavior that's not predictable from understanding
which class the partition key expression falls into, then I could agree
that's a bug.

			regards, tom lane