HANDLER Statement

HANDLER Statement is a SQL statement in the MySQL Specific category. MySQL: low-level direct table access bypassing the optimizer. Very fast for specific traversal patterns. The syntax is HANDLER table_name OPEN [AS alias]; HANDLER table_name READ index_name WHERE condition;. It returns direct table access. A typical example: HANDLER employees OPEN AS emp; HANDLER emp READ idx_last_name WHERE last_name = 'Smith'; -- Direct index access, no query planning overhead HANDLER emp READ idx_last_name NEXT; -- Read next row in index order HANDLER emp CLOSE; -- Close the handler -- Use cases: -- Extremely low-latency lookups -- Batch processing tasks -- Not for general use (bypasses locking, caching) -- 10-20% faster than SELECT in some cases A close relative is AUTO_INCREMENT, which mySQL auto-generates sequential integer values for this column. Commonly used with PRIMARY KEY. A close relative is ENGINE, which specifies the MySQL storage engine. InnoDB (default) supports transactions and foreign keys. MyISAM is faster for read-heavy.