Help me tuning performance ( Plan pasted inline)

Question

I am a newbie as far as performance tuning is concerned.
Plz check the plan. I dont understand much of the plan. Can you figure out where exactly its chewing time or looping. I can post the actual query on reqest.
Execution Plan
0 SELECT STATEMENT Optimizer=CHOOSE (Cost=112 Card=2 Bytes=296)
1 2 RECURSIVE EXECUTION OF 'SYS_LE_2_0'
2 0 TEMP TABLE TRANSFORMATION
3 2 SORT (UNIQUE) (Cost=112 Card=2 Bytes=296)
4 3 UNION-ALL
5 4 VIEW (Cost=2 Card=1 Bytes=231)
6 5 TABLE ACCESS (FULL) OF 'SYS_TEMP_0FD9D663D_F61AD09C' (Cost=2 Card=1 Bytes=175)
7 4 NESTED LOOPS (Cost=104 Card=1 Bytes=65)
8 7 MERGE JOIN (CARTESIAN) (Cost=103 Card=1 Bytes=34)
9 8 TABLE ACCESS (BY INDEX ROWID) OF 'MYTABLE1' (Cost=1 Card=1 Bytes=22)
10 9 INDEX (RANGE SCAN) OF 'MYTABLE3' (NON-UNIQUE) (Cost=1 Card=1)
11 10 TABLE ACCESS (FULL) OF 'TABLE4' (Cost=2 Card=1 Bytes=28)
12 8 BUFFER (SORT) (Cost=102 Card=8 Bytes=96)
13 12 TABLE ACCESS (FULL) OF 'MYTABLE2' (Cost=102 Card=8 Bytes=96)
14 7 TABLE ACCESS (BY INDEX ROWID) OF 'MYTABLE4' (Cost=1 Card=1 Bytes=31)
15 14 INDEX (UNIQUE SCAN) OF 'MYTABLE5' (UNIQUE)
16 15 VIEW (Cost=2 Card=1 Bytes=26)
17 16 TABLE ACCESS (FULL) OF 'SYS_TEMP_0FD9D663D_F61AD09C' (Cost=2 Card=1 Bytes=175)
Thanx in advance.
Rachit

Answer 1

Hi Rachit,
You need to do away with Full table Scans and Merge Join Cartesian's,
which i could find in the Explain Plan provided.
Merge Join Cartesian's might be bcoz you are missing some join in the where clause.
And Full table scans are a problem if u have huge data in the tables.you need to eliminate them as well.
Vig