If you’ve ever gotten a DB2 error like this…
SQL0803N One or more values in the INSERT statement, UPDATE statement, or foreign key update caused by a DELETE statement are not valid because the primary key, unique constraint or unique index identified by "1" constrains table "XX.TABLE_NAME" from having duplicate values for the index key. SQLSTATE=23505
You may be asking yourself, but exactly which unique index is causing the problem?
Use the info from the error along with this query to find out:
SELECT * FROM SYSCAT.INDEXES WHERE IID = 1 AND TABSCHEMA = 'XX' AND TABNAME = 'TABLE_NAME';
Of course you will want to replace the WHERE clause conditions with your values.