Shulou(Shulou.com)06/01 Report--

Matters needing attention in creating an index

1. Estimate index size

2. View the available space of the index tablespace

3. View temporary tablespace size

4. Creation of business leisure period

5. Online, parallel and nologging modes can be considered.

II. Predictive indexing method

The steps are as follows:

SQL > explain plan for create index idx_object_id on tt (object_id)

Explained.

SQL > set lines 200 pages 1000

SQL > select * from table (dbms_xplan.display ())

PLAN_TABLE_OUTPUT

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Plan hash value: 3757763116

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| | Id | Operation | Name | Rows | Bytes | Cost (% CPU) | Time |

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| | 0 | CREATE INDEX STATEMENT | | 2762K | 13m | 22958 (1) | 00:04:36 |

| | 1 | INDEX BUILD NON UNIQUE | IDX_OBJECT_ID |

| | 2 | SORT CREATE INDEX | | 2762k | 13m | | |

| | 3 | TABLE ACCESS FULL | TT | 2762K | 13m | 21560 (1) | 00:04:19 |

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PLAN_TABLE_OUTPUT

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Note

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-estimated index size: 67m bytes

14 rows selected.

Elapsed: 00:00:00.01

SQL >

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