=?UTF-8?B?0JDQvdC00YDQtdC5INCl0L7Qt9C+0LI=?= <avkhozov@xxxxxxxxx> writes: > create table t1 (id serial, str char(32)); > create function f1(line text) returns void as $$ > begin > perform * from t1 where str = line; > end; > $$ language plpgsql; This query is specifying a text comparison (text = text operator). Since the table column isn't text, a char-to-text conversion must happen at each line. > create function f2(line char) returns void as $$ > begin > perform * from t1 where str = line; > end; > $$ language plpgsql; This query is specifying a char(n) comparison (char = char operator). No type conversion step needed, so it's faster. regards, tom lane -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
