Re: PG 12 draft release notes

Andres Freund <andres(at)anarazel(dot)de> writes:
> On 2019-05-20 18:56:50 -0400, Tom Lane wrote:
>> I'm not sure which of my commits you want me to opine on, other than

> That was one of the main ones. I'm also specifically wondering about:

>> Author: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
>> 2019-02-09 [1fb57af92] Create the infrastructure for planner support functions.
>> <para>
>> Add support for <link linkend="sql-createfunction">function
>> selectivity</link> (Tom Lane)
>> </para>
>> </listitem>
>>
>> Hm, that message doesn't seem like an accurate description of that
>> commit (if anything it's a391ff3c?). Given that it all requires C
>> hackery, perhaps we ought to move it to the source code section?

Yes, this should be in "source code". I think it should be merged
with a391ff3c and 74dfe58a into something like

Allow extensions to create planner support functions that
can provide function-specific selectivity, cost, and
row-count estimates that can depend on the function arguments.
Support functions can also transform WHERE clauses involving
an extension's functions and operators into indexable clauses
in ways that the core code cannot for lack of detailed semantic
knowledge of those functions/operators.

> and perhaps you could opine on whether we ought to include

>> <listitem>
>> <!--
>> Author: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
>> 2019-02-11 [1d92a0c9f] Redesign the partition dependency mechanism.
>> -->
>>
>> <para>
>> Improve handling of partition dependency (Tom Lane)
>> </para>
>>
>> <para>
>> This prevents the creation of inconsistent partition hierarchies
>> in rare cases.
>> </para>
>> </listitem>

It's probably worth mentioning, but I'd say something like

Fix bugs that could cause ALTER TABLE DETACH PARTITION
to not drop objects that should be dropped, such as
automatically-created child indexes.

The rest of it is not terribly interesting from a user's standpoint,
I think.

> And lastly, opine on the int GUC fractions, microsoecond, and cost_delay
> items?

I agree with your comments on those.

regards, tom lane