Hello Experts,
To my knowledge cost are cumulative of it child step. If so what is cost of ID 1 only 3 when its child (ID 2) is 11. Why isn't cost of ID1 sum of ID1 and ID2 which is 11+3?
Also the select statement ( ID 0) is only 11, why it is not 11+3? Please help me clarify?
Thanks is advance.
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| Id | Operation | Name | Rows | Bytes | Cost |
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| 0 | SELECT STATEMENT | | 1 | 90 | 11 |
|* 1 | TABLE ACCESS BY INDEX ROWID | CLM_HDR_CLM_LN_ | 1 | 31 | 3 |
| 2 | NESTED LOOPS | | 1 | 90 | 11 |
| 3 | NESTED LOOPS SEMI | | 1 | 59 | 8 |
| 4 | NESTED LOOPS | | 1 | 43 | 6 |
|* 5 | TABLE ACCESS BY INDEX ROWID| CLAIM_HEADER | 1 | 12 | 3 |
|* 6 | INDEX UNIQUE SCAN | XPKCLAIM_HEADER | 1 | | 2 |
|* 7 | TABLE ACCESS BY INDEX ROWID| CLM_HDR_CLM_LN_ | 1 | 31 | 3 |
|* 8 | INDEX RANGE SCAN | TUNE_CAS_01 | 4 | | 2 |
|* 9 | TABLE ACCESS BY INDEX ROWID | CLM_LN_X_FUND_D | 1 | 16 | 2 |
|* 10 | INDEX RANGE SCAN | XIF3CLM_LN_X_FU | 1 | | 1 |
| 11 | INLIST ITERATOR | | | | |
|* 12 | INDEX RANGE SCAN | XAK1CLM_HDR_CLM | 1 | | 2 |
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