Hi all,
The attached patch introduces citext_pattern_ops for citext extension
type like text_pattern_ops for text type. Here are operators ~<~, ~<=~,
~>~, ~>=~ combined into citext_pattern_ops operator class. These
operators simply compare underlying citext values as C strings with
memcmp() function. This operator class isn’t supported by B-Tree index
yet, but it is a first step to do it.
Patch includes regression tests and is applicable to the latest commit
(c85ec643ff2586e2d144374f51f93bfa215088a2).
The problem of citext support for LIKE operator with B-Tree index was
mentioned in [1]. Briefly, the planner doesn’t use B-Tree index for
queries text_col LIKE ‘abc%’. I’d like to investigate how to improve it
and make another patch. I think the start point is
match_special_index_operator() function which doesn’t support custom
types. I would appreciate hearing your opinion on this.
1. https://www.postgresql.org/message-id/3924.1480351187%40sss.pgh.pa.us
--
Alexey Chernyshov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company
--
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers