Re: Updatable views/with check option parsing

I wrote:
> We can use the same technique that we used for UNION JOIN, but instead
> join, say, WITH and TIME into one token and make the time datatype
> productions look for "TIME WITHTIME ZONE" and so on. (I propose this
> rather than putting the ugliness into WITH CHECK OPTION, because this
> way we should only need one merged token and thus only one case to
> check in the filter function; AFAICS we'd need three cases if we
> merge tokens on that end of it.)

On investigation that turns out to have been a bad idea: if we do it
that way, it becomes necessary to promote WITH to a fully reserved word.
The counterexample is

CREATE VIEW v AS SELECT * FROM foo WITH ...

Is WITH an alias for foo (with no AS), or is it the start of a WITH
CHECK OPTION? No way to tell without lookahead.

While I don't think that making WITH a fully reserved word would cause
any great damage, I'm unwilling to do it just to save a couple of lines
of code. Accordingly, I propose the attached patch. This reinstates
the filter yylex function formerly used for UNION JOIN (in a slightly
cleaner fashion than it was previously done) and parses WITH CHECK
OPTION without any bison complaints, and with no new reserved words.

If no objections, I'll go ahead and apply this, and Peter can get on
with making the stub productions do something useful.

regards, tom lane