What Is a Database Transaction?

A database transaction is a sequence of actions that are executed as a single, atomic operation. Transactions in MySQL and Postgres begin with 'begin;' and end with 'commit;' or 'rollback;'. Committing applies all the changes made by the SQL statements, while rollback undoes them. Transactions also provide consistent reads, ensuring that a transaction sees a consistent view of the database even if other transactions are modifying data concurrently.