As400 Interview Questions Part 10

15 Views

Prev
Next

Here’s the 10th set of 20 AS400/IBM i interview Q&A (Data areas, LF, DFU, SQL, Subfiles, RPGLE).

1. What Are The Valid User Defined Data Area Types?

  • *DTAARA types:

    • *CHAR → character

    • *DEC → decimal

    • *LGL → logical (boolean)

2. What Is Multi-format Logical File?

  • A Logical File (LF) that combines record formats from multiple PFs.

  • Used when data must be joined or presented in different ways.

3. What Is The Select And Omit Criteria In Logical File?

  • DDS keywords in LF: SELECT includes records meeting condition, OMIT excludes records.

  • Example: OMIT WHERE FIELD = 'X'.

4. Can Fields Be Concatenated In a Logical File Level?

  • ✅ Yes, using CONCAT in DDS.

  • Example: FLD1 CONCAT FLD2.

5. When we use the "All" Keyword?

  • Used in CPYF command: MBROPT(*ALL) → copies all members.

  • Also in library lists: DSPLIB LIB(*ALLUSR).

6. What Is Difference Between CAT, TCAT, BCAT?

  • CAT → Concatenate with 1 blank in between.

  • TCAT → Trim right operand, then concatenate.

  • BCAT → Trim both operands, then concatenate.

7. In Which Specification The Report Layout Can Be Defined?

  • In O-specs (Output specifications) in RPG (for printer files).

8. What Does DFU Program allow You To Do On A Record?

  • DFU (Data File Utility) allows Add, Update, Delete, Display records in a PF without writing a program.

9. When Are The Unique Constraints Executed?

  • Enforced at insert or update time on the file.

10. When Are The Referential Constraints Executed?

  • Enforced at insert, update, or delete time depending on relationship.

  • Example: Insert fails if parent doesn’t exist.

11. Why Is The Declare Cursor Statement Used For?

  • Declares a cursor for row-by-row processing in SQL.

  • Example:

EXEC SQL DECLARE C1 CURSOR FOR SELECT * FROM MYFILE;

12. Which CL Command Can Be Used At Program Execution To Redirect The File Named In An RPG Program?

  • OVRDBF → overrides a file with another file/member before program runs.

13. How To Write *PSSR ?

  • Example RPG IV program status subroutine:

Begsr *PSSR;
   // error handling code
   *INLR = *ON;
   RETURN;
Endsr;

14. What Is Procedure Prototype And Procedure Interface?

  • Prototype: Defines how a procedure is called (parameters, return type).

  • Interface: Defines how a procedure receives parameters inside.

15. Explain The Keywords EDTCDE & EDTWRD?

  • EDTCDE → Edit Code (predefined formats, e.g., blanks, commas).

  • EDTWRD → Edit Word (user-defined mask, e.g., ‘,,9.99’).

16. What Key Word Is Used When Screen Is Re-display?

  • RSTDSP → redisplay screen.

  • Also SFLDSPCTL for subfiles.

17. What Is Overlay?

  • DDS keyword → allows one display format to overlay another without clearing screen.

18. Difference Between View And Index?

  • View → Virtual table created with SQL, shows data subset (no physical data).

  • Index → Access path created for performance, may enforce uniqueness.

19. Mandatory Keywords Of Subfile?

  • SFL (subfile record format).

  • SFLCTL (subfile control format).

  • SFLSIZ, SFLPAG (subfile size, page size).

20. What Is %LOOKUP Opcode?

  • %LOOKUP → Searches an element in array or table.

  • Returns index position if found, else 0.

✅ That’s 200 Q&A total (10 sets).
 

AS400 interview questions | Answers with explanation for 20 questions | Part10

Prev
Next
Save ()

Post Comments