Transaction Control

Initiate a transactional block and commit changes:

BEGIN;
SELECT * FROM employees;
COMMIT;

Check the current auto-commit configuration:

SHOW VARIABLES LIKE 'autocommit';

By default, MySQL operates in auto-commit mode, treating every single statement as a distinct transaction. To disable this behavior:

SET autocommit = 0;
-- or
SET autocommit = OFF;

Adjust the isolation level for the current session (e.g., to Read Committed):

SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED;

Storage Engines

Inspect the storage engine of a specific table (e.g., accounts):

SHOW TABLE STATUS LIKE 'accounts';

Switch a table's engine to InnoDB:

ALTER TABLE archive engine = InnoDB;

Duplicate a table structure (schema only) using LIKE:

CREATE TABLE archive_backup LIKE archive;

Performance Testing and Profiling

HTTP Load Testing

Create a list of URLs in urls.txt:

http://example.com/api
https://example.com/static/image.png

Run a test using http_load:

http_load -parallel 5 -seconds 30 urls.txt

Slow Query Log

The slow query log captures execution time, users, specific SQL statements, and rows returned. Its essential for identifying inefficient queries. A related feature, the