Fifteen common SAP ABAP interview questions
- What is the ABAP Data Dictionary, and what objects does it contain?
- Transparent, pooled and cluster tables — differences?
- What are the types of internal tables, and when do you use each?
- How do you improve the performance of a SELECT statement?
- FOR ALL ENTRIES — how does it work, and what are the pitfalls?
- What are BAPIs, RFCs and IDocs?
- What enhancement techniques exist: user exits, BAdIs, enhancement spots?
- What are classical, interactive and ALV reports?
- Function modules versus methods in classes?
- What is a lock object?
- What is the code-to-data paradigm in ABAP on HANA?
- What are CDS views, and why use them?
- What is AMDP?
- What is RAP?
- How do you debug and trace a slow program?
Data dictionary and internal tables
- Data Dictionary objects include tables, views, data elements, domains, structures, table types, search helps and lock objects.
- Table types: transparent tables map one-to-one to database tables; pooled and cluster tables were legacy storage types, largely converted to transparent tables on HANA.
- Internal tables: standard (index access, linear search unless sorted), sorted (kept in key order, binary search) and hashed (unique key, constant-time lookup) — choose by access pattern.
- Lock objects generate enqueue and dequeue function modules to prevent concurrent updates to the same data.
Open SQL performance
| Practice | Why |
|---|---|
| Select only needed fields | Less data transferred |
| Use WHERE clauses that match indexes | Avoid full table scans |
| Avoid SELECT inside loops | Prevents many round trips — use joins or FOR ALL ENTRIES |
| Check FOR ALL ENTRIES table isn't empty | An empty driver table selects all rows |
| Use aggregates and joins in the database | Push computation down, especially on HANA |
| Use SQL trace and runtime analysis | Measure before optimising |
Integration and enhancements
BAPIs are standardised business APIs implemented as remote-enabled function modules; RFCs are the remote call mechanism between SAP systems or external programs; IDocs are asynchronous document formats for exchanging business data between systems. Enhance standard SAP without modifying it through user exits and customer exits (older), BAdIs (object-oriented, multiple implementations possible) and implicit and explicit enhancement spots.
ABAP on HANA and modern ABAP
HANA reverses the old advice of pulling data into ABAP and processing it there: the code-to-data paradigm pushes calculations into the database. Core Data Services (CDS) views define semantically rich data models with annotations in the database layer and feed Fiori apps and analytics. ABAP Managed Database Procedures (AMDP) let you write database procedures in SQLScript managed from ABAP classes. The ABAP RESTful Application Programming Model (RAP) builds Fiori and OData services on CDS views with behaviour definitions — the modern standard for S/4HANA development. Modern ABAP syntax (inline declarations, constructor expressions) also comes up.
Reports and debugging
- Reports: classical list output, interactive drill-down lists, and ALV grids for sortable, filterable output with standard functions.
- Debugging: the ABAP debugger with breakpoints and watchpoints; SQL trace for database calls; runtime analysis for time distribution; code inspector for static checks.
Clean core and S/4HANA
S/4HANA projects increasingly follow a clean core approach: avoid modifying standard code, extend through released APIs, key-user tools and side-by-side extensions, and use modern ABAP on released objects so upgrades stay smooth. Interviewers ask how you'd meet a requirement without a modification — a good test of up-to-date practice.
Practising
Answer these out loud, in two minutes or less each, and expect a follow-up on every claim. A free AI interview assistant such as CoPilot Interview can run SAP ABAP questions as a mock interview built from your résumé and score each answer. Prepare two objects you've built — a report and an enhancement or interface — with the business requirement and one performance improvement. See also SAP coding interview questions.
Disclosure: CoPilot Interview is our product, so weigh what we say about it accordingly. Everything else on this page applies whichever tool you use, or none.
Frequently asked questions
What are common SAP ABAP interview questions?
The data dictionary, table types, internal tables, Open SQL performance, FOR ALL ENTRIES, BAPIs, RFCs and IDocs, enhancement techniques, reports and ALV, lock objects, ABAP on HANA, CDS views, AMDP and RAP.
What is the code-to-data paradigm?
On SAP HANA, pushing data-intensive calculations into the database, through CDS views, AMDP and SQL, instead of fetching data into ABAP and processing it there.
What is the pitfall of FOR ALL ENTRIES?
If the driver internal table is empty, the WHERE condition is ignored and all rows are selected. Always check the table isn't empty first, and remove duplicates.
What is RAP in SAP?
The ABAP RESTful Application Programming Model, used to build OData services and Fiori apps on CDS views with behaviour definitions — the modern approach in S/4HANA.
Practise on real interview questions
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