Re: [HACKERS] Re: subselects

> > > > Note that some assumptions have to be made about the
> > > > meaning of "(a,b) OP (c,d)", since usually we only have knowledge of the behavior of
> > > > "a OP c". Easy for the standard SQL operators, unknown for others, but maybe it is OK
> > > > to disallow those cases or to look for specific appearance of the operator to guess
> > > > the behavior (e.g. if the operator has "<" or "=" or ">" then build as "and"s and if
> > > > it has "<>" or "!" then build as "or"s.
>
> Could we restrict OPs to standard ones (like we do for subselects) - I don't
> like assumption about ORs for operators with "!" ?
> "Assume as little as possible" is good rule...

Yes, I agree. The suggestion about "!" was made without thinking very hard just to raise the
possibility. Extending to other operators in a reliable way is an interesting problem, but is
not required and can be explicitly disallowed for now.

                                                - Tom