ORA-02429: cannot drop index used for enforcement of unique /primary key

Chinese:

　　ORA-02429: can not be used to force delete unique index / primary key

Cause: The
　　user tries to delete used to force a unique / primary key index
　　because the index is the primary key constraint created automatically after creation, so delete the index is not possible, so in order to delete the index need to delete the primary key, then the index will be delete

Solution:
　　After not directly delete an index, but directly delete primary key constraint, delete the primary key constraint, the index will be automatically deleted

Example:

　　1) create a test table

CREATE TABLE TAB_TEST
(
　　ID VARCHAR2(20 BYTE),
　　NAME VARCHAR2(20 BYTE),
　　CITY VARCHAR2(10 BYTE)
)

　　2) create a primary key constraint

ALTER TABLE TAB_TEST ADD CONSTRAINT PK_TAB_TEST PRIMARY KEY (ID,NAME)

　　3) the query constraints and indexes

The SELECT CONSTRAINT_NAME the FROM the DBA_CONSTRAINTS the WHERE TABLE_NAME = ' TAB_TEST '  - primary key constraint created to return 
the SELECT INDEX_NAME is the FROM DBA_INDEXES the WHERE TABLE_NAME = ' TAB_TEST '  - creating primary key constraint, the index is created

　　4) delete the index

DROP  INDEX PK_TAB_TEST - error, ORA-02429: unable to delete indexes to enforce unique / primary key

　　5) Delete the primary key constraint

ALTER TABLE TAB_TEST DROP CONSTRAINT PK_TAB_TEST

　　6) the query constraints and indexes

The SELECT CONSTRAINT_NAME the FROM the DBA_CONSTRAINTS the WHERE TABLE_NAME = ' TAB_TEST '  - No records are returned, the primary key constraint is deleted to create 
the SELECT INDEX_NAME is the FROM DBA_INDEXES the WHERE TABLE_NAME = ' TAB_TEST '  - No records are returned, the primary key constraint is removed, the index is deleted