what is the difference between a CLUSTERED INDEX and a NON CLUSTERED INDEX?
- A CLUSTERED INDEX sorts the column into order and maintains the index.
- These are similar to a DICTIONARY where the values point to actual data.
- By default, a CLUSTERED INDEX is created for a PRIMARY KEY column.
- A table can contain only a single CLUSTERED INDEX.
- A NON-CLUSTERED INDEX is created on non-key columns in the table
- NON-CLUSTERED INDEXES don't require any sorting to store data.
- The indexes are maintained in the form of a TREE with leaves pointing to actual data rows.
- NON-CLUSTERED INDEXES take more space to maintain.
- A table can contain more than one NON-CLUSTERED INDEXES
• Added one month ago