Sql Programming Tutorials, Guides & Best Practices

SHOW INDEX FROM users;

Indexes work by creating a separate data structure that holds the indexed columns and a pointer to the actual data in the table. This allows MySQL to quickly locate and retrieve the requested data without scanning every row in the table.

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

[mysqld]
slow_query_log = ON
slow_query_log_file = /path/to/slow-query.log
long_query_time = 2

Avoid using SELECT * as it retrieves all columns, consuming more resources than necessary. Specify only the columns you need.

SELECT first_name, last_name FROM users WHERE user_id = 1;

LOCK TABLES accounts WRITE;

-- Perform operations here

UNLOCK TABLES;

• Keep transactions short to reduce the risk of deadlocks and improve performance.
• Use the appropriate isolation level based on your application’s consistency and performance requirements.
• Regularly monitor and optimize your queries to minimize lock contention.

To view the size of a specific database, you'll query the information_schema.tables table. This table contains metadata about all the tables in your databases.

Execute the following query, replacing your_database_name with the name of your database: