What is QSAM?

QSAM (Queued Sequential Access Method) is a fundamental data access method in IBM mainframe operating systems like z/OS. It's designed for sequential data processing, where records are processed in the order they appear in the dataset. QSAM is typically used for reading or writing data sequentially from or to a file, such as for batch processing, report generation, or archiving data. It provides buffering and queuing to optimize I/O operations.