ORA-01502 error in case of unusable unique index and bulk dml

Question

Hi, all.
The db is 11.2.0.3 on a linux machine.
I made a unique index unusable, and issued a dml on the table.
Howerver, oracle gave me ORA-01502 error.
In order to avoid ORA-01502 error, do I have to drop the unique index ,and do bulk dml, and recreate the index?
Or Is there any other solution without re-creating the unique index?
create table hoho.abcde as
select level col1 from dual connect by level <=1000
10:09:55 HOHO@PD1MGD>create unique index hoho.abcde_dx1 on hoho.abcde (col1);
Index created.
10:10:23 HOHO@PD1MGD>alter index hoho.abcde_dx1 unusable;
Index altered.
Elapsed: 00:00:00.03
10:11:27 HOHO@PD1MGD>delete from hoho.abcde where rownum < 11;
delete from hoho.abcde where rownum < 11
ERROR at line 1:
ORA-01502: index 'HOHO.ABCDE_DX1' or partition of such index is in unusable stateThanks in advance.
Best Regards.

Answer 1

Hi. all.
The following is from "http://docs.oracle.com/cd/E14072_01/server.112/e10595/indexes002.htm#CIHJIDJG".
Is there anyone who can show me a tip to avoid the following without dropping and re-creating an unique index?
•DML statements terminate with an error if there are any unusable indexes that are used to enforce the UNIQUE constraint.
Unusable indexes
An unusable index is ignored by the optimizer and is not maintained by DML. One reason to make an index unusable is if you want to improve the performance of bulk loads. (Bulk loads go more quickly if the database does not need to maintain indexes when inserting rows.) Instead of dropping the index and later recreating it, which requires you to recall the exact parameters of the CREATE INDEX statement, you can make the index unusable, and then just rebuild it. You can create an index in the unusable state, or you can mark an existing index or index partition unusable. The database may mark an index unusable under certain circumstances, such as when there is a failure while building the index. When one partition of a partitioned index is marked unusable, the other partitions of the index remain valid.
An unusable index or index partition must be rebuilt, or dropped and re-created, before it can be used. Truncating a table makes an unusable index valid.
Beginning with Oracle Database 11g Release 2, when you make an existing index unusable, its index segment is dropped.
The functionality of unusable indexes depends on the setting of the SKIP_UNUSABLE_INDEXES initialization parameter.
When SKIP_UNUSABLE_INDEXES is TRUE (the default), then:
•DML statements against the table proceed, but unusable indexes are not maintained.
•DML statements terminate with an error if there are any unusable indexes that are used to enforce the UNIQUE constraint.
•For non-partitioned indexes, the optimizer does not consider any unusable indexes when creating an access plan for SELECT statements. The only exception is when an index is explicitly specified with the INDEX() hint.
•For a partitioned index where one or more of the partitions are unusable, the optimizer does not consider the index if it cannot determine at query compilation time if any of the index partitions can be pruned. This is true for both partitioned and non-partitioned tables. The only exception is when an index is explicitly specified with the INDEX() hint.
When SKIP_UNUSABLE_INDEXES is FALSE, then:
•If any unusable indexes or index partitions are present, any DML statements that would cause those indexes or index partitions to be updated are terminated with an error.
•For SELECT statements, if an unusable index or unusable index partition is present but the optimizer does not choose to use it for the access plan, the statement proceeds. However, if the optimizer does choose to use the unusable index or unusable index partition, the statement terminates with an error.Thanks in advance.
Best Regards.