Clustered Index vs Non-Clustered Index in DB2

A clustered index in DB2 is a type of index where the physical order of rows in the table is the same as the order of rows in the index. This means that the data in the table is stored in the same order as the clustered index key, allowing for faster data retrieval based on the key values. In contrast, a non-clustered index in DB2 does not dictate the physical order of rows in the table.

The key difference between a clustered index and a non-clustered index in DB2 is the way data is physically stored and retrieved. With a clustered index, data is stored in the order of the index key, whereas with a non-clustered index, the index is a separate data structure that points to the physical location of the data in the table.

When choosing between a clustered index and a non-clustered index in DB2, it is important to consider the nature of the data and the types of queries that will be performed on the table. Clustered indexes are ideal for tables that are frequently queried using range queries or sorted results, as they can provide significant performance benefits. Non-clustered indexes, on the other hand, are better suited for tables with frequent insert and update operations, as they do not require reorganizing the data to maintain the index order.