Re: [Proposal] Adding callback support for custom statistics kinds

> I just remembered that we should document the new callbacks in [0] with a
> brief explanation of their purpose and a reference to test_custom_stats
> as an example of usage. What do you think?

oh, and I also realized that the documentation was updated incorrectly when
test_custom_stats was originally committed. Thought it was better to fix this
in a separate thread [0].

[0] https://www.postgresql.org/message-id/CAA5RZ0s4heX926+ZNh63u12gLd9jgauU6yiirKc7xGo1G01PXQ@mail.gmail.com

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Sami Imseih
Amazon Web Services (AWS)