In this post, you’ll learn more about the Oracle ErrorDRG-12305: column string data type is not supported for index set columns with the details on why you receive this error and the possible solution to fix it.
Oracle Error Description
DRG-12305: column string data type is not supported for index set columns
Reason for the Error DRG-12305: column string data type is not supported for index set columns
Cause: You specified a column in the column list of an index of an index set which does not have a valid datatype
How to fix the Error DRG-12305: column string data type is not supported for index set columns ?
You can fix this error in Oracle by following the below steps
Action: use only DATE, NUMBER, CHAR, or VARCHAR2 columns in index column lists