Multiple choice technology databases Which is correct about index? B-tree index used for table having completely unique colum REVERSE key index used for oracle parallel serve BIT MAP index is used for low cardinality None of these Reveal answer Fill a bubble to check yourself A,B,C Correct answer Explanation B-tree indexes are ideal for unique columns, reverse key indexes are designed to avoid contention in Oracle Parallel Server (RAC) environments, and bitmap indexes are highly efficient for columns with low cardinality.