CBO ? RBO? 很清晰的图示

QUERY IN
|
|
\ /

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| Is there a hint for table access, |
| an ORDERED, FIRST_ROWS or |
| ALL_ROWS hint ? |
| | yes
| 7.3+ Does any table have PARALLEL |-------> COST
| set ? |
| or |
| Partition Views involved? |
| |
| 8.0+ As above and additionally, |
| Are there any: |
| Index Organised Tables (IOT) |
| or |
| Partition Tables involved ? |
| |
| 8.1+ As above and additionally, |
| Are there any: |
| Domain Indexes (Inter Media) |
| or |
| Parallelism set on Indexes |
| See [NOTE:70008.1] |
| or |
| Parallel instances set on |

| an object |

| or |

| Sample clauses |

| (Datawarehousing feature) |

| or |

| Parallel CTAS |

| or |

| Function-based indexes |

| or |

| Reverse Key Indexes |

| or |

| Query rewrite |

| (materialised views) |

| or |

| ANSI JOIN syntax is used |

| in the query |

-----------------------------------
|
| no
|
----------------------------------- yes
| Is there a RULE hint ? |-------> RULE
-----------------------------------

|
| no
|

-----------------------------------
| Is RULE set at SYSTEM or SESSION | yes
| level and no CHOOSE hint ? |-------> RULE
-----------------------------------
|
| no
|
-----------------------------------
| Is ALL_ROWS or FIRST_ROWS set at | yes
| SYSTEM or SESSION level and no |-------> COST
| CHOOSE hint ? |
-----------------------------------
|
| no
|
-----------------------------------
| Are there statistics for any of | yes
| the tables ? |-------> COST
-----------------------------------
|
| no
|
RULE