A Logical Unit of Work (LUW) is the smallest unit of work in SAP that must be executed completely or not at all, following the all-or-nothing principle. It plays a crucial role in ensuring data consistency by treating a group of operations as a single transaction. If any part of the LUW fails, the entire set of changes is rolled back, preventing partial updates and maintaining system integrity.
Types of LUW in SAP
There are mainly 3 types of LUWs in ABAP/SAP:
1. Database LUW (DB LUW)
- A set of database operations executed between two database commits (
COMMIT WORK) or rollbacks (ROLLBACK WORK). - Managed by the database system.
- Each DB LUW is ended explicitly by COMMIT WORK or ROLLBACK WORK.
2. SAP LUW
- A set of one or more DB LUWs that belong together in terms of SAP application logic.
- Ensures that multiple DB LUWs are processed as a single logical unit.
- A single SAP LUW can span multiple DB LUWs.
- Controlled by function modules with update tasks (
CALL FUNCTION … IN UPDATE TASK).
✅ Example:
-
In Sales Order creation (VA01):
- DB LUW 1 → Insert Sales Order header
- DB LUW 2 → Insert Sales Order items
- DB LUW 3 → Update stock
- DB LUW 4 → FI/CO posting
👉 All DB LUWs together form one SAP LUW.
3. Logical Unit of Work in Dialog (Dialog LUW / Transaction LUW)
- The user-related transaction unit in SAP.
- It is the sequence of dialog steps (screens) between
BEGINandENDof a transaction (from start of transaction untilCOMMIT WORK). - Ensures that changes across multiple screens are consistent.
✅ Example:
-
In VA01 (Create Sales Order):
-
Screen 1: Enter header data
-
Screen 2: Enter item data
-
Screen 3: Save →
COMMIT WORKtriggers update
-
👉 All screens together = Dialog LUW.
| Type of LUW | Controlled by | Scope | Example |
|---|---|---|---|
| Database LUW | Database system | DB operations between COMMIT / ROLLBACK | INSERT + UPDATE + COMMIT |
| SAP LUW | SAP Update mechanism | One or more DB LUWs linked logically | VA01 (SO creation + FI posting) |
| Dialog LUW | SAP Transaction flow | User actions across multiple screens | VA01 screens until Save |
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DB LUW = Technical database transaction (COMMIT/ROLLBACK).
-
SAP LUW = Business transaction made up of multiple DB LUWs.
-
Dialog LUW = User’s interaction steps in a transaction.