What is the difference between clustered and non-clustered indexes?

What is the difference between clustered and non-clustered indexes?

Clustered indexes sort and store the data rows in the table based on the index key, while non-clustered indexes create a separate structure that points to the data.

Can you explain how they affect performance?

Sure! Clustered indexes can improve performance for range queries, while non-clustered indexes are better for lookups and can speed up searches without altering the data order.

When should I use one over the other?

Use a clustered index when you need fast access to a range of data, and non-clustered indexes when you need to optimize specific queries without changing the data layout.

Are there any downsides to using clustered indexes?

Yes, clustered indexes can slow down data modification operations like inserts and updates because the data needs to be physically reordered.