Re: [COMMITTERS] 'pgsql/src/backend/parser gram.y'

> Bruce Momjian <maillist(at)candle(dot)pha(dot)pa(dot)us> writes:
> >> Repair recently-introduced error in makeIndexable for LIKE:
> >> a non-leading % would be put into the >=/<= patterns. Also, repair
> >> longstanding confusion about whether %% means a literal %%. The SQL92
> >> doesn't say any such thing, and textlike() knows that, but gram.y didn't.
>
> > Houston, we have a problem. DoMatch has:
>
> > case '%':
> > /* %% is the same as % according to the SQL standard */
> > /* Advance past all %'s */
> > while (*p == '%')
>
> > Don't we want %% to be %?
>
> I looked at the spec, and this piece of code is right: there is nothing
> in the spec that says that %% means anything other than two string
> pattern matches (which of course has the same effect as one). So I made
> gram.y agree.
>
> It could be that people like Microsoft don't follow the spec... can
> anyone check this?

DoMatch, which implements LIKE clearly thinks %% is %, and I think our
users think so too. I would not change it.

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