Skillset can help you prepare! Sign up for your free Skillset account and take the first steps towards your certification.
What are the four (4) required characteristics of database transactions?
atomicity, consistency, isolation, durability
accuracy, isolation, integrity, availability
atomicity, accuracy, isolation, integrity
confidentiality, integrity, availability, authentication
Atomicity Database transactions must be atomic--that is, they must be an âall-or-nothingâ affair. If any part of the transaction fails, the entire transaction must be rolled back as if it never occurred.
Consistency All transactions must begin operating in an environment that is consistent with all of the databaseâs rules (for example, all records have a unique primary key). When the transaction is complete, the database must again be consistent with the rules, regardless of whether those rules were violated during the processing of the transaction itself. No other transaction should ever be able to utilize any inconsistent data that might be generated during the execution of another transaction.
Isolation The isolation principle requires that transactions operate separately from each other. If a database receives two SQL transactions that modify the same data, one transaction must be completed in its entirety before the other transaction is allowed to modify the same data. This prevents one transaction from working with invalid data generated as an intermediate step by another transaction.
Durability Database transactions must be durable. That is, once they are committed to the database, they must be preserved. Databases ensure durability through the use of backup mechanisms, such as transaction logs.
Train with Skillset and pass your certification exam. Faster. Guaranteed.
Study thousands of practice questions that organized by skills and ranked by difficulty.
Create a tailored training plan based on the knowledge you already possess.
Know when you’re ready for the high-stakes exam. Have the confidence that you will pass on your first attempt.