Database Transactions

SQL database transactions are essential for executing sequences of actions as single, atomic operations, involving reading, creating, updating, and removing data. In MySQL and Postgres, transactions begin with "begin;" and end with "commit;", which applies all changes atomically, while "rollback;" can undo partial transactions. This system allows concurrent queries without interference, with Postgres using multi-versioning for consistent reads and MySQL employing an undo log. Both databases offer isolation levels like Serializable, Repeatable Read, Read Committed, and Read Uncommitted, balancing data protection with performance. While MySQL uses row-level locking to manage concurrent writes, risking deadlocks, Postgres applies Serializable Snapshot Isolation with predicate locks for conflict detection, avoiding deadlocks. Understanding these mechanisms enhances effective database management.