Why Standard Indexes Fail: The Architecture of the Covering Index

In my last article, I broke down how and why to use indexes wisely for efficient lookups and data retrieval by identifying fields to index and which not to index. Can read that here . But adding a standard index in some cases is half the battle. Adding an index to a column creates a separate, organized B-Tree for that column. And at the bottom of the tree (leaf node) is the pointer. That pointer tells the database engine where the full row lives on the heap. The heap is the main table where the