Transaction and Concurrency Control

Front

What is a transaction in the context of databases?

Back

A transaction is a collection of operations that form a single logical unit of work.

Front

What happens if one operation in a transaction fails?

Back

If one operation is not successful, all other operations will be undone.

Front

What is a database request equivalent to?

Back

A database request is equivalent to a single SQL statement in an application program or transaction.

Front

What is meant by a database consistent state?

Back

A database consistent state satisfies the constraints specified in the schema.

Front

What is a transaction log used for in a DBMS?

Back

A transaction log is used to keep track of all the transactions that update the database.

Front

What does atomicity mean in the context of transactions?

Back

Atomicity requires that all operations of a transaction should be completed; otherwise, the entire transaction is aborted.

Front

What does consistency ensure in a transaction?

Back

Consistency ensures that only valid data following all rules and constraints will be written in the database.

Front

What is isolation in transaction management?

Back

Isolation means that the data used during the execution of a current transaction cannot be used by another transaction until the first one is completed.

Front

What does durability guarantee in a transaction?

Back

Durability ensures that once transaction changes are done and committed, they cannot be undone or lost.

Front

What is an example of a real-life transaction?

Back

A fund transfer, such as transferring ₱1000 from one bank account to another.