What is a transaction log in a database?
a) A record of all transactions that have been performed in the database
b) A list of active users in the database
c) A backup of the database schema
d) A list of database queries executed
Answer:
a) A record of all transactions that have been performed in the database
Explanation:
A transaction log is a record of all the transactions that have been performed in the database. It keeps track of changes to the database, including inserts, updates, and deletes, as well as transaction start and end times.
The transaction log is crucial for recovery in case of system failure, as it allows the database to roll back incomplete transactions or redo completed ones to ensure consistency.
By maintaining a transaction log, databases can ensure ACID properties and recover from crashes without losing committed data.