"select in" statment returns wrong number of rows

I've got a SQL-Sttment with many "select in (....)" statements. When I'm executing this statement, Oracle 9.2 returns me a different number of rows in comparison to the the statement with explicit written "where clauses" (where .... = .... or ... ... or .....).

Is there a difference between select in clauses and or-clauses?

An other effect when using select in clauses with oracle object functions is, that it takes a very long time.

example: select * from table(myvirtualtable(....))vt , othertable where vt.atr = othertable.atr and othertable.atr in (........)

the workaround

select * from table(myvirtualtable(....))vt , othertable where vt.atr = othertable.atr and
othertable.atr = ....
or othertable.atr = .....
or .....

works faster.

why?

greetings
Martin Received on Tue Feb 22 2005 - 02:53:26 CST