Interview Questions: Transaction Management

Qns-1: Describe Global and Local transactions in Spring.

Ans: Global transactions help to work with multiple transactional resources like relational database and message queue. Global transactions are managed through JTA and JNDI. Local transactions are resource-specific like JDBC connection. Local Transactions can work with multiple transactional resources.

Qns-2: What is the role of TransactionDefinition interface?

Ans: a. Isolation b. Propagation c. Timeout d. Read-only status

Qns-3: How can we roll back a declarative transaction?

Ans: We can use rollback-for and no-rollback-for attributes with transactional definition.

Qns-4: How many types of isolation are there?

Ans: a. ISOLATION_DEFAULT: default isolation. b. ISOLATION_READ_COMMITTED: dirty reads are prevented, non-repeatable and phantom reads are allowed. c. ISOLATION_READ_UNCOMMITTED : dirty reads are allowed, no-repeatable and phantom reads are allowed. d. ISOLATION_REPEATABLE_READ: dirty reads and non-repeatable reads are prevented but phantom reads are allowed. e. ISOLATION_SERIALIZABLE : dirty , non- repeatable reads and phantom reads are prevented.

Qns-5: How many types of Propagation are there?

Ans: Find the Propagation type. a. PROPAGATION_MANDATORY : supports current transaction and throws exception if no transaction available. b. PROPAGATION_NESTED : runs with nested transaction c. PROPAGATION_NEVER : does not run with current transaction and throws exception if current transaction exits. d. PROPAGATION_NOT_SUPPORTED : runs non -transactionaly and does not support current transaction. e. PROPAGATION_REQUIRED : runs with current transaction and create one if does not exist. f. PROPAGATION_REQUIRES_NEW : creates new transaction and suspends if exits any. g. PROPAGATION_SUPPORTS: runs current transaction and runs non -transactionaly