Greg Stark <gsstark@mit.edu> writes:
> Removing <,<=,>,>= would be trivial.
... and not backwards-compatible. If we did that then cases involving
unlabeled row expressions would no longer work as they did in prior
releases. For example
select (1,2,3) < (4,5,6);
is accepted by all releases back to 7.0, and probably much further (but
7.0 is the oldest I have handy to test). The only reason the code in
parse_expr.c appears new is that the functionality used to be in gram.y.
I'd like to see this fixed to comply with the spec, but given the lack
of complaints about the existing behavior over so many years, ripping
it out meanwhile doesn't seem appropriate.
regards, tom lane