alter session set skip_unusable_indexes=true

1.

alter session set skip_unusable_indexes=true;

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2. 请问如何恢复unusable的索引

[url]http://www.itpub.net/395459[/url],1.html 

2.1

SQL> create table test as select * from all_objects;

 

Table created.

 

SQL> create index t_owner_ind on test(owner);

 

Index created.

 

SQL> alter index t_owner_ind unusable;

 

Index altered.

 

SQL> drop index t_owner_ind;

 

Index dropped.

 

SQL>

2.2

SQL> create table test as select * from sys.dba_objects;

 

Table created.

 

SQL> alter table test add constraint unique_id unique(object_id);

 

Table altered.

 

SQL> select index_name from user_indexes where lowercase(table_name)='test';

select index_name from user_indexes where lowercase(table_name)='test'

*

ERROR at line 1:

ORA-00904: "LOWERCASE": invalid identifier

 

 

SQL> select index_name from user_indexes where lower(table_name)='test';

 

INDEX_NAME

------------------------------

UNIQUE_ID

 

SQL> select segment_name from user_segments;

 

SEGMENT_NAME

--------------------------------------------------------------------------------

UNIQUE_ID

TEST_CON

TEST

SALGRADE

BONUS

PK_EMP

EMP

PK_DEPT

DEPT

 

9 rows selected.

 

SQL> alter table test drop constraint unique_id;

 

Table altered.

 

SQL> select index_name from user_indexes where lower(table_name)='test';

 

no rows selected

 

SQL> select segment_name from user_segments;

 

SEGMENT_NAME

--------------------------------------------------------------------------------

TEST_CON

TEST

SALGRADE

BONUS

PK_EMP

EMP

PK_DEPT

DEPT

 

8 rows selected.

 

SQL>

 

不存在 unique_id segment ．

3. skip_unusable_indexes使用的几点补充- -

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4. ORA-01502 state unusable 错误成因和解决方法 ( 二 )

[url]http://www.cndw.com/tech/data/2006051167352.asp[/url]

5. SKIP_UNUSABLE_INDEXES 的使用与索引实效解决方法

[url]http://blog.chinaunix.net/u/7121/showart_270366.html[/url]