Difference Between Nested Transaction and Multi Transaction in SQL Server

Nested Transactions are logical levels within a single physical transaction where only the outermost COMMIT actually commits and any ROLLBACK rolls back the entire transaction. Multiple Transactions are independent transactions where each COMMIT or ROLLBACK affects only its own transaction scope.

Feature	Nested Transaction	Multiple Transactions
Definition	Transaction inside another transaction	Separate independent transactions
BEGIN TRAN Count	Multiple BEGIN TRAN statements before final COMMIT	Each transaction starts and ends independently
Physical Transaction	One	Multiple
Logical Transaction Levels	Multiple	One per transaction
@@TRANCOUNT	Increases with each BEGIN TRAN	Resets to 0 after each COMMIT
Independent Commit	❌ No	✅ Yes
Independent Rollback	❌ No	✅ Yes
Inner COMMIT Commits Data?	❌ No	✅ Yes
Rollback Effect	Entire transaction rolls back	Only current transaction rolls back
Transaction Log BEGIN Record	One physical BEGIN	One BEGIN per transaction
Transaction Log COMMIT Record	One physical COMMIT	One COMMIT per transaction
Lock Release	Only after outer COMMIT	After each COMMIT
Blocking Risk	Higher	Lower
Production Usage	Rare	Very Common
Best Use Case	Stored procedure call hierarchy	Normal OLTP processing