Oracle11g新特性invisibleindex(不可见的索引) - 数据库编程

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1 - filter("OBJECT_ID"=10)
统计信息
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1 recursive calls
0 db block gets
544 consistent gets
0 physical reads
0 redo size
1195 bytes sent via SQL*Net to client
337 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
1 rows processed

--让数据库看到不可见索引，可以通过改变一个参数
SQL> alter session set optimizer_use_invisible_indexes = true;
SQL> select * from test where object_id = 10;
执行计划
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Plan hash value: 255872589
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| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
-----------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 100 | 2 (0)| 00:00:01 |
| 1 | TABLE ACCESS BY INDEX ROWID| TEST | 1 | 100 | 2 (0)| 00:00:01 |
|* 2 | INDEX RANGE SCAN | IND_T_OBJECT_ID | 1 | | 1 (0)| 00:00:01 |
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Predicate Information (identified by operation id):
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2 - access("OBJECT_ID"=10)
统计信息
----------------------------------------------------------
1 recursive calls
0 db block gets
4 consistent gets
0 physical reads
0 redo size
1195 bytes sent via SQL*Net to client
337 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
1 rows processed

Oracle11g新特性invisibleindex(不可见的索引)(二)