Re: Re: pg_stat_statements normalisation without invasive changes to the parser (was: Next steps on pg_stat_statements normalisation)

On 18 March 2012 22:46, Andrew Dunstan <andrew(at)dunslane(dot)net> wrote:
> If you want to generate the tests using some tool, then use whatever works
> for you, be it Python or Perl or Valgol, but ideally what is committed (and
> this what should be in your patch) will be the SQL output of that, not the
> generator plus input.

The reason that I'd prefer to use Perl or even Python to generate
pg_regress input, and then have that infrastructure committed is
because it's a lot more natural and succint to deal with the problem
that way. I would have imagined that a patch that repeats the same
boilerplate again and again, to test almost every minor facet of
normalisation would be frowned upon. However, if you prefer that, it
can easily be accommodated.

The best approach might be to commit the output of the Python script
as well as the python script itself, with some clean-up work. That
way, no one is actually required to run the Python script themselves
as part of a standard build, and so they have no basis to complain
about additional dependencies. We can run the regression tests from
the buildfarm without any additional infrastructure to invoke the
python script to generate the pg_regress tests each time. When time
comes to change the representation of the query tree, which is not
going to be that frequent an event, but will occur every once in a
while, the author of the relevant patch should think to add some tests
to my existing set, and verify that they pass. That's going to be made
a lot easier by having them edit a file that expresses the problem in
terms whether two queries should be equivalent or distinct, or what a
given query's final canonicalised representation should look like, all
with minimal boilerplate. I'm only concerned with making the patch as
easy as possible to maintain.

--
Peter Geoghegan       http://www.2ndQuadrant.com/
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