Re: Latest patches break one of our unit-test, related to RLS
Tom Lane <tgl@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Dominique Devienne <ddevienne@gmail.com>
Cc: Laurenz Albe <laurenz.albe@cybertec.at>, pgsql-general@postgresql.org
Date: 2025-09-12T14:07:06Z
Lists: pgsql-general
Dominique Devienne <ddevienne@gmail.com> writes:
>> This DOES look like a bug, no? I've done regexes for a long time,
>> and these two forms should be equivalent IMHO. --DD
Yeah, I agree it's busted. You can use EXPLAIN VERBOSE to see the
translated-to-POSIX pattern, and it's wrong:
regression=# explain verbose with t(v) as (values ('foo:bar'), ('foo/bar'), ('foo0bar'))
select v from t where v similar to 'foo[\d\w]_%';
QUERY PLAN
--------------------------------------------------------------
Values Scan on "*VALUES*" (cost=0.00..0.05 rows=1 width=32)
Output: "*VALUES*".column1
Filter: ("*VALUES*".column1 ~ '^(?:foo[\d\w]_%)$'::text)
(3 rows)
The _ and % are not getting converted to their POSIX equivalents
("." and ".*"). Your other example still does that correctly:
regression=# explain verbose with t(v) as (values ('foo:bar'), ('foo/bar'), ('foo0bar'))
select v from t where v similar to 'foo[0-9a-zA-Z]_%';
QUERY PLAN
------------------------------------------------------------------
Values Scan on "*VALUES*" (cost=0.00..0.05 rows=1 width=32)
Output: "*VALUES*".column1
Filter: ("*VALUES*".column1 ~ '^(?:foo[0-9a-zA-Z]..*)$'::text)
(3 rows)
So e3ffc3e91 was at least one brick shy of a load.
regards, tom lane
Commits
-
Amend recent fix for SIMILAR TO regex conversion.
- f75ff1b141a5 14.20 landed
- e09adb5b9fc9 17.7 landed
- cdf7feb96562 19 (unreleased) landed
- 9fd531534b64 15.15 landed
- 802308693f2f 18.0 landed
- 308773617d2d 13.23 landed
- 281ad4ed11d2 16.11 landed
-
Fix conversion of SIMILAR TO regexes for character classes
- e3ffc3e91d04 17.6 cited