Learn the cause and how to resolve the ORA-01448 error message in Oracle.
When you stumble upon an ORA-01448 error, the following error message will appear:
ORA-01448: index need to be dropped before altering to preferred type
You tried to execute a ALTER TABLE MODIFY attempting to change the information kind of an listed column to a LONG datatype. Columns with the LONG datatype can no longer be indexed.
The option(s) to resolve this Oracle error are:
Drop all indexes that reference the column that you want to alternate to a LONG datatype.
Select a different column to index.
For example, if you had a table known as suppliers defined as follows:
CREATE TABLE suppliers ( supplier_name varchar2(50), city varchar2(35), state varchar2(2), zip varchar2(10), CONSTRAINT suppliers_pk PRIMARY KEY (supplier_name) );
Then executed the following ALTER TABLE statement
ALTER TABLE suppliers MODIFY supplier_name LONG;
You would receive the following error message:
You may want to right the error with the aid of disposing of the most important key from the suppliers table:
ALTER TABLE suppliers DROP CONSTRAINT suppliers_pk;
However, once you have modified to your column to a LONG datatype, you can no longer include this column in any index.