Tag Archives: non clustered

SQL Tip-6 | Use Covering Index to solve key lookup issues

Do you have Key Lookup problem? Key lookup taking most of the query time. then probably this is the best time to know more about covering indexes. Covering Index can solve all key lookup problems. A Non Clustered Index which contains all columns which are referred by a Query (in Select, Where or Join) is …

Using Covering Index

A Non Clustered Index which contains all columns which are referred by a Query (in Select, Where or Join) is called Covering Index. In other words When all columns which are required to satisfy the query are included in a non-clustered Index to avoid extra key lookup that index is known as Covering index. This …