UNION Operator Makes the query slow

[skdas]

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..?

[slimdave]

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

[skdas]

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

[slimdave]

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.