From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andres Freund <andres@anarazel.de>
cc: David Fetter <david@fetter.org>,
        PostgreSQL Development <pgsql-hackers@postgresql.org>
Subject: Re: New EXPLAIN option: ALL
In-reply-to: <20190507215449.3a4yb5kkoloq7yyw@alap3.anarazel.de>
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Comments: In-reply-to Andres Freund <andres@anarazel.de>
	message dated "Tue, 07 May 2019 14:54:49 -0700"
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Date: Tue, 07 May 2019 18:06:43 -0400
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Andres Freund <andres@anarazel.de> writes:
> As I said, I don't think ALL is a good idea under any name.  Like it
> just makes no sense to have ANALYZE, SUMMARY, VERBOSE, BUFFERS,
> SETTINGS, FORMAT controlled by one option, unless you call it DWIM. It's
> several separate axis (query is executed or not (ANALYZE), verbosity
> (SUMMARY, VERBOSE), collecting additional information (BUFFERS, TIMING),
> output format).

FWIW, I find this line of argument fairly convincing.  There may well
be a case for rethinking just how EXPLAIN's options behave, but "ALL"
doesn't seem like a good conceptual model.

One idea that comes to mind is that VERBOSE could be redefined as some
sort of package of primitive options, including all of the "additional
information" options, with the ability to turn individual ones off again
if you wanted.  So for example (VERBOSE, BUFFERS OFF) would give you
everything except buffer stats.  We'd need a separate flag/flags to
control what VERBOSE originally did, but that doesn't bother me ---
it's an opportunity for more clarity of definition, anyway.

I do feel that it's a good idea to keep ANALYZE separate. "Execute
the query or not" is a mighty fundamental thing.  I've never liked
that name for the option though --- maybe we could deprecate it
in favor of EXECUTE?

			regards, tom lane