What are indexes and how is indexing useful?

Question

Accepted Answer

Indexes in databases are data structures that improve the speed of data retrieval operations.

Indexes are data structures that store a small portion of the table data in an optimized format for quick retrieval.
They help in speeding up data retrieval operations such as SELECT queries by reducing the number of rows that need to be scanned.
Indexes can be created on one or more columns of a table to improve the performance of queries that filter or sort by those columns.
Examples of indexes include primary keys, unique keys, and indexes created on frequently queried columns.

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