Does Oracle re-hash the driving table for each join on the same table columns?
Say you've got the following query on 9i: SELECT /*+ USE_HASH(t2 t3) */ * FROM table1 t1 -- this has lots of rows LEFT JOIN table2 t2 ON t1.col1 = t2.col1 AND t1.col2 = t2.col2 LEFT JOIN table3 t3 ON t1.col1 = t3.col1 AND t1.col2 = t3.col2 Due to 9i not having RIGHT OUTER HASH JOIN, it needs to hash table1 for both joins. D...