What types of transactions can occur during parallel operations without proper isolation, leading to data integrity issues?
sobes.tech AI
Answer from AI
In parallel operations without proper transaction isolation, the following types of problems can occur, affecting data integrity:
-
Dirty Read — a transaction reads data that has been modified by another transaction but not yet committed. If the second transaction rolls back, the first transaction will have incorrect data.
-
Non-repeatable Read — when reading the same data multiple times within a transaction, the data may change due to another parallel transaction.
-
Phantom Read — when executing the same query with a condition multiple times within a transaction, new rows inserted by another transaction may appear.
-
Lost Update — two transactions read and modify the same data simultaneously, and one transaction's changes overwrite the other's without awareness.
These problems are addressed using transaction isolation levels (READ UNCOMMITTED, READ COMMITTED, REPEATABLE READ, SERIALIZABLE) and locking mechanisms.