pgsql-bugs@postgresql.org writes:
> For some SQL queries (for an example see below) the operator "=" on text does not work, that is, no rows are
returned,although some should be returned.In PostgreSQL 7.0.3 I avoided this problem by using
> the LIKE operator instead of the "=" operator.In PostgreSQL 7.1 this
> trick does not work anymore. But I found another way to avoid the problem by using SUBSTR. For example I used
substr(text1,1,8)=substr(text2,1,8)instead of text1=text2 or
> text1 like text2, where 8 is the length of both texts.
Perhaps you are failing to consider trailing blanks in one or both input
values?
regards, tom lane