In the field of databases in computer science, a transaction log (also transaction journal, database log, binary log or audit trail) is a history of actions executed by a database management system to guarantee ACID properties over crashes or hardware failures. Physically, a log is a file of updates done to the database, stored in stable storage.
If, after a start, the database is found in an inconsistent state or not been shut down properly, the database management system reviews the database logs for uncommitted transactions and rolls back the changes made by these transactions. Additionally, all transactions that are already committed but whose changes were not yet materialized in the database are re-applied. Both are done to ensure atomicity and durability of transactions.
This term is not to be confused with other, human-readable logs that a database management system usually provides.
Read more about Transaction Log: Anatomy of A General Database Log, Types of Database Log Records, Tables
Famous quotes containing the word log:
“There was now no road further, the river being the only highway, and but half a dozen log huts, confined to its banks, to be met with for thirty miles. On either hand, and beyond, was a wholly uninhabited wilderness, stretching to Canada.”
—Henry David Thoreau (1817–1862)