>>>>> "Tom" == Tom Lane <tgl@sss.pgh.pa.us> writes:
>> What about error handling? If the user specifies agg(distinct x)>> where x is not sortable, do we leave it to the
plannerto detect>> that (which means not reporting the error position?)
Tom> Well, at the moment there's only going to be a sort-basedTom> implementation, so I don't object to throwing an
errorfor thatTom> as soon as possible. OTOH I wouldn't recommend expending a lotTom> of code to do it there. I would
hopethat most of the parser'sTom> work for this can be shared with the existing support forTom> query-level ORDER
BY/DISTINCT.
The code already uses transformSortClause for most of the work, but
reusing the existing code for DISTINCT would have required more
refactoring than I was happy with, because transformDistinct etc.
all have error message text which is specific to SELECT DISTINCT etc.
Let's see how it falls out in the next patch.
--
Andrew.
