Re: Introduce WAIT_EVENT_EXTENSION and WAIT_EVENT_BUFFER_PIN

On Mon, May 15, 2023 at 11:29:56AM -0700, Andres Freund wrote:
> Without an explanation for why this change is needed for [1], it's hard to
> give useful feedback...

The point is to integrate the wait event classes for buffer pin and
extension into the txt file that automates the creation of the SGML
and C code associated to them. Doing the refactoring of this patch
has two advantages:
- Being able to easily organize the tables for each wait event type
alphabetically, the same way as HEAD, for all wait event classes.
- Minimizing the number of exception rules needed in the perl script
that transforms the txt file into SGML and the C code to list all the
events associated in a class, where one function is used for each wait
event class. Currently the wait event class extension does not use
that.

This impacts only the internal object names, not the wait event
strings or the class associated to them. So this does not change the
contents of pg_stat_activity.
--
Michael