What is the difference between clustered and non-clustered indexes in a relational database management system (RDBMS)?

The Difference Between Clustered and Non-Clustered Indexes in RDBMS

When discussing the difference between clustered and non-clustered indexes in a relational database management system (RDBMS), it's important to understand how each type of index influences the organization and retrieval of data within a database.

Clustered Indexes

A clustered index determines the physical order of data in a table by sorting the rows based on the index key. In a clustered index, the data rows are stored on disk in the same order as the index key, leading to improved retrieval performance for range queries and ordered data access.

Non-Clustered Indexes

In contrast, a non-clustered index does not affect the physical order of data in a table. Instead, it creates a separate structure that includes the indexed columns and pointers to the actual data rows. Non-clustered indexes are beneficial for speeding up queries that involve columns not included in the clustered index or for supporting multiple indexes on a single table.

Focus Keyword: RDBMS Indexes

Overall, the primary difference between clustered and non-clustered indexes in an RDBMS lies in how they organize and store data on disk, ultimately impacting the query performance and data retrieval efficiency of the database system.

Understanding the distinction between these two types of indexes is crucial for optimizing database performance and designing efficient data access strategies within a relational database management system.