Transaction processing, ACID (Atomicity, Consistency, Isolation, Durability), record locking and redundancy
No description yet. This curated deck is ready for daily study.
Card preview (10)
What is meant by referential integrity?
The process of ensuring consistency, this ensures that information is not removed if it is required elsewhere in a linked database
What is meant by a transaction?
A transaction is a single operation executed on data
What is meant by transaction processing?
Transaction processing is when a series of actions is performed on one of these transactions
What does ACID stand for?
• Atomicity • Consistency • Isolation • Durability
What is meant by atomicity?
A transaction must be processed in its entirety or not at all
What is meant by consistency?
A transaction must maintain the referential integrity rules between linked tables
What is meant by isolation?
Simultaneous executions of transactions should lead to the same result as if they were executed one after the other
What is meant by durability?
Once a transaction has been executed it will remain so regardless of the circumstances surrounding it
What is meant by record locking?
• The process of preventing simultaneous access to records in a database, used in order to prevent inconsistencies or a loss of updates • While one person is editing a record, this ‘locks’ the record so others cannot access the same record
What is meant by redundancy?
• The process of having one or more copies of the data in physically different locations. • This means that if there is any damage to one copy the others can be recovered