Re: Parser extensions (maybe for 10?)

2016-04-18 17:25 GMT+02:00 Aleksander Alekseev <a(dot)alekseev(at)postgrespro(dot)ru>:

> > I cannot to imagine extensible parser based on bison. But the parser
> > can be replaced by custom parser.
> >
> > Some like pgpool or pgbouncer does. The extension can assign own
> > parser. Custom parser will be called first, and the integrated parser
> > will be used from extension or as fallback. This can helps with new
> > statements for background workers, theoretically it can helps with
> > extending PostgreSQL SQL. Custom parser can do translation from SQL1
> > to SQL2 dialect, or can do translation from SQL1 to internal calls.
> > The custom parser usually should not implement full SQL - only few
> > statements.
> >
> > Is it this idea more workable?
>
> What if there are two or more contribs that extend the parser? Can we
> be sure that these contribs will not conflict?
>

It depends - can be allowed only one - like plpgsql extensions, or can be
serialized like pg log extensions

Regards

Pavel

>
> --
> Best regards,
> Aleksander Alekseev
> http://eax.me/
>