How Does In Memory Computing Affect SQL Server Recovery?
Built-in provisionsHekaton allows DBAs to select high priority tables and objects that need to be stored in RAM for super-fast querying. However, the underlying architecture has also been engineered to create a localized backup of that data:Transaction logJust like a standard disk-based database, Hekaton also relies on a transaction log record to track operations, and assist with SQL Server recovery. To ensure complete coverage, Hekaton integrates both disk-based and memory-based transaction logs, writing both to disk in batches.Understanding the Data FileRather than the traditional page structures used for data rows, Hekaton uses a pair of sequential files - Data and Delta files. The Data file contains free-form data rows that are then linked using in-memory indexes. Every time a row is changed by an INSERT or UPDATE statement, the changed row is appended to the end of the Data file.To maintain the speed of operation and to maintain an accurate audit trail, when a row is deleted or updated from an in-memory table, it is not removed from, or changed in the Data file.