How do you change index status from unusable to valid?

How do you change index status from unusable to valid?

Fix Invalid Or Unusable Index

1. Example:
2. SQL> insert into scott.
3. insert into scott.dept(deptno,dname,loc) values(50,’Test’,’Test’)
4. *
5. ERROR at line 1:
6. ORA-01502: index ‘SCOTT.PK_DEPT’ or partition of such index is in unusable State.
7. SQL> select ‘alter index ‘||owner||’.’
8. SQL> alter index SCOTT.

What causes Ora-01502 index or partition of such index is in unusable state?

In this case, we truncated the main table, deliberately made the index unusable and then restore it from a backup table. Eventually, we saw ORA-01502. This is because the optimizer want to use the index for your INSERT INTO SELECT statement, but it found the index is broken (UNUSABLE).

How do I enable and disable indexes in Oracle?

To disable an index, you run an ALTER INDEX command: ALTER INDEX index_name ON table_name DISABLE; You can replace the index_name with the name of your index, and the table_name with the name of the table that the index is created on.

How do you find unusable indexes?

Check unusable and not valid Index in Oracle Query will cover the complete index with partition index and sub partition index. Result will give you the rebuild command of invalid or unusable index. You can directly run that and on sqlplus and make them valid or usable state. WHERE STATUS=’UNUSABLE’;

How do I fix unusable index in Oracle?

To repair the index, it must be re-created with the ALTER INDEX… REBUILD command….This can be avoided by using the ONLINE keyword.

1. Create Table and insert row in it: —————————————-
2. Check the Index Status.
3. Move the Table and Check Status:
4. Rebuild The Index:

What is Rule hint Oracle?

In Oracle SQL “rule” hint means use the Rule Based Optimizer (RBO) instead of CBO (Cost Based Optimizer): since Oracle 10 it is no more supported. So for Oracle you cannot discard it: it should be taken into account but without support …

How do you make an unusable index usable?

To make an index unusable:

1. Query the data dictionary to determine whether an existing index or index partition is usable or unusable.
2. Make an index or index partition unusable by specifying the UNUSABLE keyword.
3. Optionally, query the data dictionary to verify the status change.

What makes an oracle index unusable?

Oracle indexes can go into a UNUSABLE state after maintenance operation on the table or if the index is marked as ‘unusable’ with an ALTER INDEX command. A direct path load against a table or partition will also leave its indexes unusable.

How do you fix unusable indexes?

To repair the index, it must be re-created with the ALTER INDEX… REBUILD command. for each index key. When the new index is completed, the original unusable index is dropped.

What is index monitoring in Oracle?

Index monitoring allows unused indexes to be identified accurately, removing the risks associated with dropping useful indexes. It is important to make sure that index monitoring is performed over a representative time period.