Explain plan execution

Execution Plan

   0 SELECT STATEMENT Optimizer=CHOOSE (Cost=4 Card=2 Bytes=384)    1 0 SORT (ORDER BY) (Cost=4 Card=2 Bytes=384)

   2    1     NESTED LOOPS (Cost=3 Card=2 Bytes=384)
   3    2       TABLE ACCESS (BY INDEX ROWID) OF 'DM_SYSOBJECT_S' (Cos
          t=2 Card=2 Bytes=212)

   4    3         INDEX (RANGE SCAN) OF 'D_1F00C73D8000000F' (NON-UNIQ
          UE) (Cost=3 Card=10)

   5    2       TABLE ACCESS (BY INDEX ROWID) OF 'OS_DOCUMENT_S' (Cost
          =2 Card=1 Bytes=86)

   6    5         INDEX (UNIQUE SCAN) OF 'D_1F00C73D80000D01' (UNIQUE)

I will like to know what numbers in second "column" mean, I see there are two 2's - one 3 and one 5. Does that mean step 5 (based on second column) is done first, then srep3. What about two 2 steps. Which one is done first?

Is DMS_SYSOBJECT_S really the driving table for nested loop join. I will be really surprised) because this table has lot more rows that OS_DOCUMNET_S table. I would think OS_DOCUMENT_S should be driving table.

Thanks a lot, Received on Fri Apr 14 2006 - 12:18:11 CDT