ORA-01502 index is in unusable state
SQL> show parameter skip
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
skip_unusable_indexes boolean TRUE
默认情况下skip_unusable_indexes=true
SQL> create table tt (id int,name varchar2(100))
2 ;
Table created.
SQL> create table tt1 (id int,name varchar2(100))
2 ;
Table created.
SQL> create unique index tt_index on tt (id);
Index created.
创建 unique index
SQL> alter table tt add primary key (id) using index;
Table altered.
SQL> create index tt1_index on tt1(id);
Index created.
创建 normal index
SQL> select index_name,status from user_indexes;
INDEX_NAME STATUS
------------------------------ --------
TT1_INDEX VALID
TT_INDEX VALID
期间有向tt,tt1表insert 了一笔数据。
SQL> alter table tt move tablespace test;
Table altered.
SQL> alter table tt1 move tablespace test;
Table altered.
SQL> select index_name,status from user_indexes;
INDEX_NAME STATUS
------------------------------ --------
TT1_INDEX UNUSABLE
TT_INDEX UNUSABLE
SQL> insert into tt values(1,'a');
insert into tt values(1,'a')
*
ERROR at line 1:
ORA-01502: index 'TEST.TT_INDEX' or partition of such index is in unusable
state
unique index出现了此错误
SQL> insert into tt1 values(1,'a');
1 row created.
normal index没有出现错误
SQL> commit;
Commit complete.
SQL> select * from tt;
ID NAME
---------- ----------
1 b
SQL> select * from tt1;
ID NAME
---------- ----------
1 b
1 a
SQL> alter index tt1_index rebuild;
Index altered.
SQL> alter index tt_index rebuild;
Index altered.
SQL> select index_name,status from user_indexes;
INDEX_NAME STATUS
------------------------------ --------
TT1_INDEX VALID
TT_INDEX VALID
SQL> insert into tt values(1,'a');
insert into tt values(1,'a')
*
ERROR at line 1:
ORA-00001: unique constraint (TEST.SYS_C003773) violated
如果index为valid的话，insert相同的数据，会报ora-00001的错误。
当把index变为unusable，truncate table之后，index会变为valid
SQL> alter index tt_index unusable;
Index altered.
SQL> select index_name,status from user_indexes;
INDEX_NAME STATUS
------------------------------ --------
TT1_INDEX VALID
TT_INDEX UNUSABLE
SQL> truncate table tt;
Table truncated.
SQL> select index_name,status from user_indexes;
INDEX_NAME STATUS
------------------------------ --------
TT1_INDEX VALID
TT_INDEX VALID
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