Database Indexing
Database indexing is a data structure technique used to improve the speed of data retrieval operations on a database table at the cost of additional writes and storage space. It works by creating a separate, optimized structure (an index) that maps key values to their physical locations in the database, allowing queries to find data without scanning the entire table. Indexes are typically implemented using data structures like B-trees, hash tables, or bitmap indexes, depending on the database system and use case.
Developers should learn and use database indexing when building applications with performance-critical queries, especially for large datasets where full table scans would be too slow. It is essential for optimizing read-heavy operations, such as searching, filtering, or sorting data in relational databases like MySQL, PostgreSQL, or SQL Server. Proper indexing can reduce query times from seconds to milliseconds, making it crucial for scalable web applications, analytics systems, and any scenario requiring fast data access.