Re: [OSSTEST PATCH 06/14] sg-report-flight: Use WITH clause to use index for $anypassq

[Ian Jackson <ian.jackson@xxxxxxxxxx>]

George Dunlap writes ("Re: [OSSTEST PATCH 06/14] sg-report-flight: Use WITH 
clause to use index for $anypassq"):
> > On Jul 21, 2020, at 7:41 PM, Ian Jackson <ian.jackson@xxxxxxxxxxxxx> wrote:
> > +    # In psql 9.6 this WITH clause makes postgresql do the steps query
> > +    # first.  This is good because if this test never passed we can
> > +    # determine that really quickly using the new index, without
> > +    # having to scan the flights table.  (If the test passed we will
> > +    # probably not have to look at many flights to find one, so in
> > +    # that case this is not much worse.)
> 
> Seems a bit weird, but OK.  The SQL looks the same, so:
> 
> Reviewed-by: George Dunlap <george.dunlap@xxxxxxxxxx>

Thanks.  This business with the WITH clause as an optimisation fence
is well-known in Postgres circles, it seems.

Ian.