ORA-01408: such column list already indexed
Oracle PL/SQL error message: ORA-01408: such column list already indexed.
Cause:
A CREATE INDEX statement specified a column that is already indexed. A single column may be indexed only once. Additional indexes may be created on the column if it is used as a portion of a concatenated index, that is, if the index consists of multiple columns.
Solution:
Do not attempt to re-index the column, as it is unnecessary. To create a concatenated key, specify one or more additional columns in the CREATE INDEX statement.
Example:
CREATE INDEX first_name_idx2 ON students (first_name);
Output:
ORA-01408: such column list already indexed
Correct:
CREATE INDEX first_name_idx2 ON students (first_name, last_name);
Output:
index FIRST_NAME_IDX2 created.