Sql Programming Tutorials, Guides & Best Practices

Indexes are data structures that improve the speed of data retrieval operations on a database table. They are similar to the index in a book, which allows you to quickly find specific topics without scanning every page. In MySQL, indexes can be applied to columns to speed up queries involving those columns.

Indexes can be created when a table is first created or added later using the CREATE INDEX statement.

The slow query log records queries that exceed a specified execution time. Analyzing this log can help you identify and optimize slow queries.

To enable the slow query log, add the following lines to your my.cnf or my.ini file:

EXPLAIN SELECT * FROM users WHERE user_id = 1;

The output provides details like:

SELECT name FROM employees WHERE department = 'Engineering';

Ensure indexed columns are used: