Patent ID: 7305421

Claim:
A method of logging and recovery in a transaction-processing system having a main memory for storing a database, the method comprising: partitioning a database into slots; generating log records, each representing updates to the database by storing a physical image of an update database portion; assigning an update sequence number representing a sequence of database updates to each log record for each slot and to the updated database portion, the assigning includes an allocated slot sequence number (SSN) representing a sequence of slot updates as the update sequence number, and the assigning includes an assigned a page version number (PVN) that is incremented when a page is formatted with a different slot size; storing the generated log records into one or more log disks; and recovering from a system failure by replaying the generated log records read from said one or more log disks in a sequence independent from the order of log generation, wherein replaying includes selectively applying the physical image in the read log record to a corresponding slot of the database based on the slot sequence number assigned to the corresponding slot.