Storage Engine Subsystems

Most relational database products have two primary components, a relational engine and a storage engine. Storage engine subsystems include:

• Mechanisms that store data in files and find pages, files, and extents
• Record management for accessing records on pages
• Access methods by using B-trees, which help find records quickly by using record identifiers
• Concurrency control for locking, which helps implement the physical lock manager and locking protocols for page-level or record-level locking
• I/O buffer management
• Logging and recovery
• Utilities for backup and restore, consistency checking, and bulk data loading