On Fri, Jun 1, 2018 at 11:53 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
I agree though that it seems strange to special-case SQLValueFunction rather than any-stable-expression. As long as the evaluation happens at executor start (i.e. with the query's run-time snapshot) it should be reasonable to simplify any stable expression.
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.