On Tue, May 06, 2025 at 01:32:48PM -0500, Sami Imseih wrote:
> Without properly accounting for the boundaries of the list of expressions, i.e.,
> the start and end positions of '(' and ')' or '[' and ']' and normalizing the
> expressions in between, it will be very difficult for the normalization to
> behave sanely.
FWIW, this is exactly the kind of issues we have spent time on when
improving the location detection of sub-queries for some DDL patterns,
and the parser is the only path I am aware of where this can be done
sanely because the extra characters that may, or may not, be included
in some of the expressions would be naturally discarded based on the @
locations we retrieve.
For reference, this story is part of 499edb09741b, more precisely
around this part of the thread:
https://www.postgresql.org/message-id/CACJufxF9hqyfmKEdpiG%3DPbrGdKVNP2BQjHFJh4q6639sV7NmvQ%40mail.gmail.com
(FWIW, I've seen assumptions around the detection of specific
locations done outside the parser in pg_hint_plan as well, that did
not finish well because the code makes assumptions that natural
parsers are just better at because they're designed to detect such
cases.)
--
Michael
