"Dmitri Bichko" <dbichko@aveopharma.com> writes:
> Ok, I'm thoroughly confused.
You didn't say which PG version you are using, but if it's something
reasonably recent then it should be able to push upper qual conditions
down into a UNION. I think you are getting bit by this restriction:
* 3. For subqueries using UNION/UNION ALL/INTERSECT/INTERSECT ALL, we can* push quals into each component query, but
thequals can only reference* subquery columns that suffer no type coercions in the set operation.* Otherwise there are
possiblesemantic gotchas.
You're getting burnt because you're unioning a text with a varchar.
Make the column types the same and it'll work better.
regards, tom lane
