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