UNION Operator Makes the query slow

Hi,

I have two queries. Each of the queries run fast.

But when I use UNION in between the two queries. I do not get the result set.

It runs for ever..

Any suggestion..?

UNION provides an implicit unique sort. use UNION ALL if you don't want that.

Even UNION ALL, the query result does not come out..

use the sql*pluscommand ...
set autotrace traceonly explain
... to getexecution plansfor the two separatequeries and for the two queries union all'd together, and post them all here.