>> > CREATE TABLE A (x int PRIMARY KEY, real v);
>> > CREATE TABLE B (x int);
>> >
>> > SELECT sum(v) FROM A WHERE EXISTS (SELECT 1 FROM B WHERE A.x=B.x);
>>
>> This seems to be a reasonably-performing workaround:
>>
>> SELECT DISTINCT x INTO TEMP C FROM A,B WHERE A.x=B.x;
>> SELECT sum(v) FROM A,C WHERE A.x=C.x;
>
> Hmm, given that, would something like:
>
> select sum(v) from
> (select distinct on(x) x,v from a,b where a.x=b.x) as foo;
Excellent. Thanks!
--
Itai Zukerman <http://www.math-hat.com/~zukerman/>