Re: Re: [PATCHES] Select parser at runtime

Ian Lance Taylor <ian@airs.com> writes:
> For example: the datatypes have different names; the set of reserved
> words is different; Oracle uses a weird syntax for outer joins.

Is it really possible to fix these things strictly in the parser
(ie, without any semantic analysis)?  For example, I don't quite see
how you're going to translate Oracle-style outer joins to SQL standard
style without figuring out which fields belong to which relations.
Keep in mind the cardinal rule for the parsing step: Thou Shalt Not
Do Any Database Access (because the parser must work even in
transaction-aborted state, else how do we recognize ROLLBACK command?)
        regards, tom lane