Data management Flashcards
What are ACID transactions?
ACID transactions are transactions in database that uphold atomicity, consistency, isolation and durability values to ensure data integrity
What is atomicity?
Atomicity refers to ensuring that all parts of transactions is performed successfully, if any part of transaction fails, entire transaction is rolled backed and not performed.
What is consistency?
Consistency refers to ensuring that transactions bring database from one consistent state to another consistent state, maintaining all predefined rules and constraints.
Eg: Updating BC number will ensure that BC number is of the same format
What is isolation?
Isolation refers to transactions being executed is isolated from other transactions, thus intermediate transactions are not visible to other transactions.
This prevents concurrent transactions from interfering with each other.
What is Durability?
Durability refers to guaranteeing that once transaction is completed, changes to data will remain, even in the event of a system failure.
What is a data backup and its purpose
Backups refer to short term copies of data.
It is usually stored offsite.
Purpose: Backups prevent data loss in events of current data in database gets destroyed
What is a data archival and its purpose?
Data archival is the process of moving data to cheaper and less frequently accessed storage mode.
Purpose: It’s purpose is to free up space in primary storage systems and thus lowers cost of storing data
What is version control and its purpose
Version control refers to a system that records changes made to files over time so that previous versions can be recalled if necessary.
Purpose: Allows users to rollback to previous working versions, which allows programmers to fix their mistakes while minimising disruptions
