What is the maximum number of indexes recommended for a table?

The recommendation of having a maximum of five indexes for a table is rooted in performance optimization and maintenance considerations within database management systems. While indexes can significantly improve query performance by allowing the database engine to quickly locate data without scanning the entire table, having too many indexes can lead to diminishing returns.

Each index consumes system resources, including additional disk space and memory. Furthermore, when data is modified (inserted, updated, or deleted), all relevant indexes must also be updated, which can slow down these operations. Therefore, striking a balance is crucial. Five indexes are typically seen as a reasonable number to enhance query performance without overly complicating data modifications and management. This number allows for effective indexing strategies for common queries while minimizing the negative impacts associated with maintaining multiple indexes.

The overall approach to indexing should focus on the specific access patterns of the application, ensuring that the most frequently queried columns are indexed effectively within the recommended limits.