On Tue, May 19, 2020 at 11:32 AM Tom Lane <t...@sss.pgh.pa.us> wrote: > Before we go much further on this, we should have some proof > that there's actually material benefit to be gained. I spent some > time just now trying to relax the AS restriction by ripping out > postfix ops, and the results were not too promising. Indeed the > postfix-ops problem goes away, but then you find out that SQL's > random syntax choices for type names become the stumbling block. > An example here is that given > > SELECT 'foo'::character varying > > it's not clear if "varying" is supposed to be part of the type name or a > column label. It looks to me like we'd have to increase the reserved-ness > of VARYING, PRECISION, and about half a dozen currently-unreserved > keywords involved in INTERVAL syntax, including such popular column names > as "month", "day", and "year". > > Plus I got conflicts on WITHIN, GROUP, and FILTER from ordered-set > aggregate syntax; those are currently unreserved keywords, but they > can't be allowed as AS-less column labels.
I came to similar conclusions a couple of years ago: https://www.postgresql.org/message-id/ca+tgmoyzpvt7uihjwgktytivhhlncp0ylavcoipe-lyg3w2...@mail.gmail.com What I proposed at the time was creating a new category of keywords. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
