Hi Hari!
What do you mean with "bad" index?
What exactly do you want to do, when you do a "CHECK DATA"? (table structure consistency check? data completeness or correctness check?)
If you refer to bad indexes as they are present in other DBMS (like Oracle or MaxDB) then the answer is: there are never bad indexes.
Indexes are not persisted in SAP HANA but rebuild at column load time.
That way, they cannot deviate from the table content and be stored and left like this.
For checking table data there is e.g. the uniqueChecker script available (just look up the SAP note for it for details).
- Lars