IBM - AS/400 Interview Questions & Answers

Question 1. How Do You Pass Parameters In Cl?

Answer :

Using PARM keyword.

Question 2. What Are The Valid User Defined Data Area Types?

Answer :

CHAR, NUMERIC and LOGICAL

Question 3. What Is Multi-format Logical File?

Answer :

Logical which uses fields from two or more physical files.

Question 4. What Is The Select And Omit Criteria In Logical File?

Answer :

This is used to specify rules for the Selection/Omission of records from a Physical File.

Question 5. Can Fields Be Concatenated Ina Logical File Level?

Answer :

Yes. by using CONCAT keyword

Question 6. When Would The All Keyword Be Used?

Answer :

Use with Select or Omit, to select/omit records.

Question 7. What Are The Different Types Of Keywords In Display Files?

Answer :

File level, Record format level, Field level

Question 8. What Is Difference Between Cat, Tcat, Bcat?

Answer :

CAT - Concatenate two variables or constants into one continuous string.

BCAT - Truncates all trailing blanks in the first character string, one blank is inserted, then the two character strings are concatenated.

TCAT - Truncates all trailing blanks in the first character string, the two character strings are concatenated.

Question 9. What Are The Different Types Of Messages In Cl?

Answer :

Immediate message, Break message, Program message, User message.

Question 10. How To Trap Errors In Cl?

Answer :

By using Monitor Message Command (MONMSG)

Question 11. What Is The Maximum Length Of A Variable Name In Cl?

Answer :

Maximum 11 characters (including '&')

Question 12. What Are The Limitations Of Cl (compare To Rpg) ?

Answer :

You can not use CL program to ADD or UPDATE records in database files.
Use Printer or ICF files.
Use Program described files.
Use the concept of subfile (to display more than one record), but a single output message subfile is a special type of subfile that is supported well in CL.
Use subroutines.
You cannot declare more than one object (file) in a CL programme.

Question 13. What Is The Use Of Header Specification In Rpg/400?

Answer :

It identifies by H in column 6, provides informaion about generating and running programs.

Question 14. When Will Dump And Debug Opcodes Be Ignored?

Answer :

If blank is specified in position 15 of H specs.

Question 15. Specify Different Indicators Used In Rpg?

Answer :

Overflow indicators
Record Identifying Indicators
Field Indicators
Resulting Indicators
Control Level Indicators

Question 16. What Are Control Level Indicators?

Answer :

L1 to L9 used to identify certain fields on control fields and then used to condition which operations are to be processed at detail or total calculation or output time.

Question 17. What Is The Use Of E Specification In Rpg?

Answer :

Extension Specs describes all record address files, arrays and tables.

Question 18. What Is The Use Of L Specs In Rpg?

Answer :

Line counter specification can be used to describe printer file to indicate the length of the form and number of lines per page.

Question 19. In Which Specification The Report Layout Can Be Defined?

Answer :

O Specification.

Question 20. How Many Files Can Be Defined In F Specs?

Answer :

50

Question 21. How Many Printer Files Can Be Defined In F Specs ?

Answer :

8

Question 22. A Program Variable Coded In An Embedded Sql Statement Is Referred To As?

Answer :

Host Variable

Question 23. Which Of The Cl Command Can Be Used To Determine Which Logical Files Are Dependent On A Specific File?

Answer :

DSPDBR

Question 24. What Does Dfu Program You To Do On A Record?

Answer :

Insert, Update Delete & File Enquiry.

Question 25. When Are The Unique Constraints Executed?

Answer :

During Insert.

Question 26. When Are The Referential Constraints Executed?

Answer :

Insert, Update & Delete.

Question 27. How Many Triggers Can Be Associated With A File?

Answer :

6(Maximum)

Question 28. Why Is The Declare Cursor Statement Is Used For?

Answer :

To define & name the cursor & specify rows to be fetched.

Question 29. What Do We Can Do With The Embedded Sql Statements?

Answer :

We can Insert/Update/Delete records, fetch records, fetch values from records into variables.

Question 30. Which Cl Command Is Used To Trap Error Messages During Program Execution?

Answer :

MONMSG

Question 31. Which Cl Command Can Be Used At Program Execution To Redirect The File Named In An Rpg Program?

Answer :

OVRDBF

Question 32. How To Write *pssr ?

Answer :

It just similar to any other subroutine.
*PSSR BEGSR
………………
………………
…………….
ENDSR

Question 33. What Is Procedure ?

Answer :

A procedure is the set of self contained high level language statements that can perform a particular task and then returns to a caller.

Question 34. What Is Procedure Prototype And Procedure Interface.

Answer :

Procedure Prototype
In this section we specify the name of the procedure along with PR.
D PROC1 PR
Procedure Interface
It is section where we define all the parameter which are receiving or returning some values.
D PROC1 PI 5 0
D PARMA 5 0
D PARMB 5 0

Question 35. How To Define Global Parameter In Ile ?

Answer :

Declare a variable with key word EXPORT and while using this variable in anther program declare with IMPORT keyword.

Question 36. What Is The Disadvantage Of Using Global Variable?

Answer :

We can not trace out at which point the value of variable is changed.

Question 37. What Is Service Program?

Answer :

A Service Program is a collection of runnable procedures and available data items easily accessible by other ILE programs. In many respects it is similar to a subroutine library and procedure library.

A service program differs from a program in two ways:

It does not contain a program entry procedure. This means that you cannot call a service program using the CALL operation.

A service program is bound into a program or other service programs using binding by reference.

Question 38. What Is *iso Date Format?

Answer :

YYYY-MM-DD for other formats refer to IBM manual or ERIS document.

Question 39. If We Tried To Move Year Part Of *iso Date Into A Field Of Length 3, What Will Happen ?

Answer :

Program crashes, as in case of *ISO format it required fields of 4,2,2.

Question 40. How To Avoid Using Indicators In Ile ?

Answer :

By using the standard Built In Expressions like %FOUND,%EOF, NOT %EOF, %BOF, NOT %BOF…etc.
Display / Printer File

Question 41. Explain The Keywords Edtcde & Edtwrd?

Answer :

EDTCDE & EDTWRD are key words used for formatting purpose. EDTCDE cannot be applied to Character filed. And EDTCDE has some Codes pre-defined for example,

EDTCDE(Z) – for suppressing the leading zero Y – for date field.
EDTWRD can be used to define user defined formatting for a fields.

Question 42. What Are The Important Factors In Error Message Subfile ?

Answer :

We must define error message record format (SFLMSG). And a Program Queue. (PGMQ) and Record format is associated to a line number.

Question 43. How To Define To Define A Hidden Filed In Dspf ?

Answer :

Define a filed in a DSPF of use HIDDEN.(H)

Question 44. How To Get The Cursor Position?

Answer :

With the help of RTNCSRLOC keyword, here we need to define a field to get row and column. Length of variable should be 5,0 fixed We can specify *FILED for filed *REC for Record on which a key is pressed.

Question 45. What Is Overlay?

Answer :

It allows a record format to be displayed on screen retaining the previous displayed record formats.

Question 46. What Key Word Is Used When Screen Is Re-display?

Answer :

RSTDSP is a parameter to be specified at compile time for display file.

Question 47. Command Attention Key And Command Function Key ?

Answer :

With the help of Command attention key we can pass only the indicator status to program not the data from screen. While command function key passes indicator status as well as a data from screen to program.

Question 48. How To Validate Input Values In Display File ?

Answer :

With the help of Validity check key words VALUE, RANGE, COMP

Question 49. Different Type Of Cursor?

Answer :

Two types of Cursor
Simple / Serial Cursor
A serial cursor is one defined without SCROLL key word
For serial cursor each row is fetched only once per OPEN When it is opened it is positioned before the first row in the table.
To use serial cursor we have to re-issue OPEN

Scrollable Cursor which is defined with SCROLL key word.
Cursor defined with SCROLL key word
Rows of cursor can be fetched many times
When it is opened it is positioned before the first row in the table.
When the FETCH is issued , the cursor is positioned to the row of the table that is specified by the POSITION option. (FIRST, LAST, PREV, NEXT, RELATIVE)

Question 50. Writing An Sql Statement From Selecting Records From Two Files Using Single Statement And Nested Select Statement.

Answer :

Using Single statement.
SELECT * FROM FILE1, FILE2
WHERE FILE1.FLD1 = FILE2.FLD1

Question 51. Difference Between View And Index ?

Answer :

View will not any data.. It only shows a data from table while Index has a Indexing Data for a sequence on which Index is created. View is similar to Logical file without having Key and Index is similar to Logical File having Key (as keyed logical file has access path data) Table is similar to PF.

Question 52. What Is The Sequence When Using Cursor?

Answer :

Define Cursor ,Declare Cursor ,Open Cursor ,Fetch record ,Processing ,Close Cursor

Question 53. What Are The Three Types Of Keywords Associated With Printer File ?

Answer :

File level, Record level & Field level.

Question 54. Difference Between Sflrcdnbr And Sflnxtchg?

Answer :

SFLRCDNBR will give the RRN of the First record displayed on the screen at a given time. Whenever a record is changed on display file. An MDT is set ON. If an indicator is associated with SLFNXTCHG and it is SETON then READC will read only the changed record. And if the indicator is not associated and it is seton it READC reads all the records from sub-file.

Question 55. How Can See Logical File Based On Which Physical File And Vice Versa

Answer :

DSPDBR

Question 56. How Can U Check No Of Records In A File?

Answer :

DSPFD

Question 57. How Do U Compile Rpgle Program?

Answer :

Either thru 15 or crtrpgmod

Question 58. Is Module Executable?

Answer :

No You need to create an RPG prog to run the module.

Question 59. What Are The Different Commands Used In Rlu ?

Answer :

DR - Define Record, CLC - Change Line for Continuation, CLR - Change Line for Record, SD - Create Sample Data, VF - View Fields, NP - New Page, DC - Define Constants, DF - Define Fields, CF - Centre Fields & SP - Space Fields evenly.

Question 60. What Is The Command Used To Invoke Rlu ?

Answer :

STRRLU.

Question 61. What Are Different Record Spacing Keywords In Rlu ?

Answer :

SKIPA, SKIPB, SPACEA & SPACEB.

Question 62. Mandatory Keywords Of Sub File?

Answer :

SFL, SFLCTL, SFLDSP, SFLSIZ, SFLPAG are the mandatory key words

Question 63. What Is Procedure?

Answer :

A procedure is the set of self-contained high level language statements that can perform a particular task and then returns to a caller.

Question 64. What Is Lokup Opcode?

Answer :

Look’s for a particular element of an array

Question 65. How Many Files, Printer Files You Can Describe In A Rpg?

Answer :

50 files and 8 printers

Question 66. How Do Handle File Exception/error?

Answer :

*INFDS ,*PSSR defining it in F spec

Question 67. Distinguish Between Terminating A Program Through Seton Lr And Return?

Answer :

LR closes all the files used in the program and RETURN is used to return the control to the parent program.

Question 68. How Will You Add A Field To Physical File Already Containing Data?

Answer :

With CPYF command and *NOCHK & *DROP

Question 69. What Are The Uses Of Factor1, Factor2 And Result Field For The Rpg Operation Code Parm?

Answer :

It is add value of FACTOR1 to FACTOR2 or compare the value of FACTOR 2 with FACTOR1.

Question 70. How Will You Find A String Using Pdm?

Answer :

By using FNDSTRPDM.

Question 71. How Will You Search An Array?

Answer :

LOKUP

Question 72. What Are The Different Types Of Arrays?

Answer :

Preruntime gets populated at the time input. Runtime gets populated at the time execution.Compile time gets populated at the time of compilation.

Question 73. What Is Message File?

Answer :

It is file which contain messages created by the user through which a user can display own message while validating.

Question 74. What Does Defn Do?

Answer :

It is used to define a field based on the value specified in FACTOR 1.

Question 75. What Are Two Types Of Record Are Used In Subfile?

Answer :

SUBFILE RECORD FORMAT and SUBFILE CONTROL RECORD FORMAT.

Question 76. What Are Dds Required For Subfile?

Answer :

SUBFILE DISPLAY (SFLDSP) SUBFILE DISPLAY CONTROL (SFLDSPCTL) SUBFILE CLEAR (SFLCLR) SUBFILE SIZE (SFLSIZE) SUBFILE PAGE (SFLPAGE).

Question 77. What Is Elastic And Non Elastic Subrile?

Answer :

When subfile size is greater then subfile page size it is called elastic subfile and when subfile size is equal to subfile page size it is called non-elastic subfile.

Question 78. What Is Sflinz And Sflrna?

Answer :

SFLINZ stands for subfile initialize. It initialized all the character field as blanks and numeric fields as zeros. SFLRNA stands for subfile record not active (It means records are there in the subfile but active).

Question 79. Can You Display A Empty Subfile?

Answer :

Yes by using the keyword SFLINZ and SFLRNA.

Question 80. Why Do We Use Readc? What Is Sflnxtchg?

Answer :

READC is to read those records which have changed in the subfile. If you validate a record in subfile on some condition all the invalid records can display in reverse image. The first which have changed and made valid and released still displaying in reverse image. The records have read even it has not been changed due to SFLNXTCHG.

Question 81. How Do You Read Changed Records Backward In Subfile?

Answer :

NOT POSSIBLE.

Question 82. How You Will Find An Error Which Is Not In The First Page Of The Subfile Without Using Rolldown Key?

Answer :

By using keyword SFLRCDNBR.

Question 83. What Is Sflrolval?

Answer :

By using this keyword you can tell system to roll on of records when the user presses ROLLDOWN key (For this you define a hidden of 4 byte).

Question 84. How You Will Know Whether You Are In Sfldrop Or Sflfold Mode?

Answer :

By using the keyword SFLMODE.

Question 85. How You Get The Relative Record In A Subfile In Which Cursor Is Located?

Answer :

By using the keyword SFLCUSRRN (Subfile cursor relative record number).

Question 86. What Is Qcmdexc?

Answer :

It is used to execute a single CL command within the RPG program.

Question 87. What Are The Different Opcodes Available In Rpg For Database Access ?

Answer :

READ, CHAIN, WRITE, UPDAT, DELET, SETLL, SETGT, READE, READP, REDPE, OPEN, CLOSE, FORCE, NEXT, UNLCK.

Question 88. How Can Database Records Be Read Without Lock ?

Answer :

Put 'N' in position 53 of C specs.

Question 89. What Does Check Opcode Do ?

Answer :

The check operation verifies that each character in the base string (factor 2) is among the ` character indicated in the comparator string(factor 1).

Question 90. In Conjunction With Which Statements Can Orxx And Andxx Conditions Be Used ?

Answer :

DOUxx, DOWxx, IFxx, and WHxx.

Question 91. What Does Opcode Post Do ?

Answer :

Puts information in INFDS.

Question 92. Can You Have Multiple Key Lists For A Single File ?

Answer :

Yes.

Question 93. What Are The Different Types Of Arrays Available In Rpg ?

Answer :

Pre-execution time array.
Compile time array.
Execution time array.

Question 94. Can We Define Multi-dimensional Arrays In Rpg ?

Answer :

No.

Question 95. What Is Xfoot Opcode ?

Answer :

Adds all the elements in a numeric array, and places the sum in the result field.

Question 96. During Input Operation Which Indicator Position Is Seton If There Is A Record Lock?

Answer :

LO indicator position is seton.

Question 97. What Is The Difference Between *like And *namvar ?

Answer :

*LIKE defines the variables as in database.
*NAMVAR is used to define variables as data area.

Question 98. What Would Be The Effect On The Field Where Reverse Image, Underline And Highlight Display Attributes Are Active ?

Answer :

The result is same as if you had specified ND.

Question 99. What Is The Purpose Of Ovrdta And Ovrata Keywords ?

Answer :

OVRDTA keyword (field or record level) can be used to override the existing data contents of a field or record already on the display.

OVRATA keyword (field or record level) can be used to override the existing display attributes of a field or record already on the display.

Question 100. What Keyword Must Be Used With Protect Keyword ?

Answer :

OVERLAY

Question 101. What Is Rpg ?

Answer :

Report Program Generator.

Question 102. Where Will Control Be Passed After The Execution Of The *pssr Subroutine If The Factor2 Of The Endsr Is Blank ?

Answer :

Control will return to the next sequential instruction.

Question 103. What Is The Maximum Number Of Subfiles That Can Specified In A Display File ?

Answer :

512

Question 104. The Maximum Number Of Subfiles That Can Defined In A Rpg Program For One Display File Is ___ .

Answer :

24

Question 105. The Maximum Number Of Subfiles That Can Be Active For A Single File Is ____ .

Answer :

12

Question 106. What Are The Different Opcodes Used For File Operation On A Subfile In A Rpg Pgm?

Answer :

READ, READC, CHAIN,UPDAT and WRITE

Question 107. How Will You Display A Particular Page In Subfile ?

Answer :

Move a valid relative record number(RRN) in the field specified using SFLRCDNBR keyword in DDS.

Question 108. Can A Single Screen Format Occupy A Screen Area Above And Below A Subfile Format ?

Answer :

Not possible.

Question 109. What Is Sflpag And Sflsiz ?

Answer :

SFLPAG : it is an attribute which specifies the number of records that can be displayed in a screen.

SFLSIZ : it is an attribute which specifies the number of records can be stored in the subfile.

Question 110. How To Pick Up The Changed Records Every Time In A Subfile After The First Change Made ?

Answer :

Seton SFLNXTCHG keyword indicator and update the subfile record.

Question 111. How Do You Specify The Number Of Records To Roll In A Subfile ?

Answer :

Use SFLROLVAL keyword in DDS along with the number, which specifies the number of records to scroll at a time.

Question 112. What Are The Three Line Types In Rlu ?

Answer :

Report line, Filler line & Sample line.

Question 113. What Is The Function Of Rlu ?

Answer :

To design & prototype a report.

Question 114. Define What A Data Area Is Along With A Brief Example Of What It May Be Used For?

Answer :

Data area is a storage area to store limited information.
Example: a new and unique customer number is generated whenever a new customer is added to customer master file. Data area keeps track of last record added and add 1 to it. Through program we can access new customer number.

Question 115. Define What A Data Queue Is Along With A Brief Example Of What It May Be Used For?

Answer :

Data queues provides communication between programs by calling API's QSNDDTAQ and QRCVDTAQ along with parameters like data queue name, library in which data queue exists, variable to store the number of characters to be sent, variable to store the information to be sent. We can send the same data queue to the many programs.

Question 116. What Is The Difference Between Udate And The System Date?

Answer :

UDATE supports two-digit year. The format is *MDY (MMDDYY).
*DATE (system date) supports four digit year. The format is *MDYY (MMDDYYYY).

Question 117. List Some Of The Commonly Used Commands For Debugging?

Answer :

STRDBG(for batch jobs), STRISDB.

Question 118. Define The Rcvf Command?

Answer :

RCVF command used to receive the records either from the data base file or device file.

Question 119. Define The Purpose Of The %sst Function?

Answer :

To extract the information from the specified string.

Question 120. Define The Purpose Of The *cat Function?

Answer :

To concatenate the two strings into a one string.

Question 121. Define The Purpose Of The *bcat Function?

Answer :

To concatenate the two strings by placing a single blank in a resultant.

Question 122. Describe The Difference Between The Dowxx And Douxx Operations?

Answer :

DOWxx : If the condition becomes true, then only the group of instructions allowed executing.
DOUxx : Irrespective of condition, it will execute at least one time.

Question 123. Define The Purpose Of The Leave Operation?

Answer :

If you specify LEAVE, the control transfers to the statement below the ENDDO.

Question 124. Define The Purpose Of The Iter Operation?

Answer :

If you specify the ITER, the groups of statements are allowed to execute repeatedly.

Question 125. How Can You Check For A Records Existence Without Causing And I/o (chain/read)?

Answer :

With the help of File Information Data Structure, we can check existence of records in a physical file. The code is described below: In File description continuation line (IPFK), KINFDS RCDS IRCDS DS I *RECORD #RCDS with the above code we can check the existence of records in a file without causing I/O operation.

Question 126. What Is Message Subfile?

Answer :

Message subfile is special file contains multiple messages taken from program message queue and placed in message sub file for display on the screen.

Question 127. What Is The Purpose Of Putovr (put With Explicit Override) Keyword?

Answer :

Use this record-level keyword to permit the override of either display file attributes or data contents of specific fields within a record displayed on the work station device.

Question 128. What Are Necessary Keywords To Code Message Subfile?

Answer :

SFLMSGRCD, SFLMSGKEY, SFLPGMQ

Question 129. What Is The Difference Between Seton Lr And Retrn?

Answer :

If you specify SETON LR, all the files used in program will be closed.
If you specify RETRN, all the files used in program will remain open.

Question 130. What Is The Purpose Of Ovrdta (override Data) Keyword?

Answer :

Use this field level keyword with PUTOVR keyword to override the existing the data contents of a field already on the display.

Question 131. What Is The Maximum Number Of Record Formats In Dspf?

Answer :

1024 (One thousand and twenty four)

Question 132. What Is The Maximum Number Of Fields Under A Record Format Of Physical File?

Answer :

8000 (eight thousand)

Question 133. What Is The Maximum Number Of Parameters Allowed In Rpg?

Answer :

255 (Two hundred and fifty five)

Question 134. What Is The Maximum Number Of Parameters Allowed In Clp?

Answer :

43 (Forty three)

Question 135. What Is The Maximum Number Of Subroutines Allowed In Rpg?

Answer :

254 (Two hundred and fifty four)

Question 136. What Is The Maximum Number Of Files Allowed In Rpg?

Answer :

50 (Fifty including eight printer file)

Question 137. What Is Maximum Number Of Arrays Allowed In Rpg?

Answer :

250 (Two hundred and Fifty )

Question 138. Where Can You Specify An Indicator In Lokup Operation?

Answer :

In 'EQ' position.

Question 139. What Is A Member?

Answer :

It is a subset of data records of a physical file.

Question 140. What Is A Physical File?

Answer :

Physical file nothing but a table contains a only one record format in which we can describe the field definitions and descriptions.

Question 141. What Is A Logical File?

Answer :

It is nothing but a logical view provided by the physical file.

Question 142. What Is Join Logical File?

Answer :

Join logical file joins more than one file. The maximum of number of files allowed to join is 32 (thirty two).

Question 143. What Are The Necessary Keywords For The Join Logical File?

Answer :

JDFTVAL, JFILE, JOIN, JFLD, JREF.

Question 144. What Is A Non-join Logical File?

Answer :

It only provides logical view based on the physical file. This is also called as regular logical file.

Question 145. What Is The Necessary Keyword For Non-join Logical File?

Answer :

PFILE (which is record level keyword)

Question 146. How Many Levels Are There In A Physical File?

Answer :

Four levels. They are File level, Record level, Field level, Key field level.

Question 147. What Is The Use Of Unique Keyword And What Level It Is Defined?

Answer :

It will avoid to enter duplicate key values. We have to define it in a file level.

Question 148. At What Level S,o Are Defined And What They Will Do?

Answer :

S, O are to defined at key field level. The purpose Select/Omit logic is depends on the criteria (condition) given at the key field level (At function entry) it selects and omits the records. The S/O is allowed in Logical file only.

Question 149. What Is The Difference Between Packed Decimal And Zoned Decimal?

Answer :

Packed decimal : One digit occupies 1 byte.
Zoned decimal : One digit occupies 2 bytes.

Question 150. What Is Default Data Type (if You Define Decimals '0') In Physical File?

Answer :

Packed decimal

Question 151. What Is Default Data Type For The Fields(sub Fields) Defined In Data Structures In Rpg?

Answer :

Zoned decimal

Question 152. What Is The Use Of Jdftval In Join Logical File?

Answer :

If you specify JDFTVAL at file level, even the primary file record does not match with secondary file record, the join takes place.

Question 153. Is It Possible To Create A Physical File Without Dds?

Answer :

Yes. With the help of CRTPF we can achieve this. But we have to give record length.

Question 154. What Is A Keyed Physical File?

Answer :

Defining a field as a key in physical file. Hence we can access records through the key field.

Question 155. What Is A Composite Key?

Answer :

Defining more than one key as a key field in physical file.

Question 156. What Is Logical File?

Answer :

A Logical file is an Access path to the Physical File.

Question 157. How Can You Specify No Duplicate Key?

Answer :

By defining the unique key.

Question 158. What Is The Command To Know How Many Lf Are Related To A Pf?

Answer :

DSPDBR (Display Database Relationship)

Question 159. What Is The Command To Know Key Fields Of File?

Answer :

DSPFD (F4) *ACCPTH(Access Path).

Question 160. What Is A Join Logical File?

Answer :

A join Logical File can be built over the two PF’s, with the PF’s ‘joined’ by a common key value. It is available for read access.

Question 161. Can A Join Logical File Be Updated?

Answer :

No.

Question 162. Using Dfu, User Will Be Able To ___________ From Physical File?

Answer :

Add/Update/Selected or all fields.

Question 163. What Is The Difference Between Normal Upddta To Pf And Updating Using Dfu Program?

Answer :

Both are same only difference is DFU allows you to add or change selected fields.

Question 164. What Is Library?

Answer :

A library is a system object that serves as a directory to other objects or collection of object.

Question 165. What Is Library List?

Answer :

A job’s library list defines the path of libraries that the job follows when trying to locate programs, files or other As/400 objects.

Question 166. Difference Between Source Physical File & Physical File?

Answer :

Source Physical File contains members who contain source statements & Physical File contains members, which contain data.

Question 167. What Is The Object Type Of Pf, Lf, Printer File & Display File?

Answer :

*File

Question 168. What Are The Different Methods To Access Seu?

Answer :

Use the Start Source Entry Utility command (STRSEU) Option 8 from STRPGMMNU Through Program Development Manager (PDM)

Question 169. Which Are The Member Types Which Seu Supports?

Answer :

RPG, CL, PF, LF, PRTF & DSPF.

Question 170. In Which Specs Arrays, Tables & Constants Are Defined?

Answer :

In I Specs.

Question 171. What Is A Spool File?

Answer :

Printed output items placed in an output queue are known as spooled files.

Question 172. How Many Specs Are There In Rpg & Which Are They?

Answer :

There are 7 Specs in RPG they are H, F, E, L, I, C & O.

Question 173. What Is The Difference Between Goto & Exsr?

Answer :

EXSR is a conditional branching while a GOTO is an unconditional branching.

Question 174. Difference Between Ca & Cf?

Answer :

CA: - It does not retains the value into the buffer memory. CF: - It retains the value into the buffer memory.

Question 175. What Does Exfmt Does?

Answer :

Write & Read.

Question 176. What Does The Ovrdbf Command Do?

Answer :

It overrides the PF temporarily for a job.

Question 177. How Does The Runqry Show The Output?

Answer :

RUNQRY shows the output always in RRN (Relative Record Number) & not in keyed sequence.

Question 178. How Many Printer Files Maximum Can Be Used In Single Rpg Program?

Answer :

8 because of the overflow indicators OA-OG & OV.

Question 179. When You Are Defining A Flat File In Your Program In F Specs Which Format Will You Specify?

Answer :

Flat File: - F (Fixed Length) Other File: - E (Externally Described)

Question 180. Difference Between Skip Before & Space Before?

Answer :

Skip before leaves the specified no. of lines moving to the next page while Space before leaves the specified no. of lines on that page.

Question 181. Which Indicator Is Used For Read?

Answer :

EQ (Equal to)

Question 182. How Many Types Of Display Are Available On As/400 For User Interaction?

Answer :

4 Types they are Entry, Menu, Information & List Display.

Question 183. What Are The Basic Features Of Seu?

Answer :

Prompt depending upon type, shows right hand side date & left hand side the line number.

Question 184. Which Are The Figurative Constants Used In Rpg?

Answer :

*ZERO,*BLANK, *ZEROS, *BLANKS, *HIVAL, *LOVAL, *OFF, *ON & *ALL.

Question 185. What Is The Syntax For Plist?

Answer :

*ENTRY PLIST PARM

Question 186. What Are Indicators?

Answer :

Indicators are inbuilt class of variables for RPG.

Question 187. What Is Cab?

Answer :

It compares Factor1 with Factor2 & if condition is true, control is transferred to label designated in the result field. The label specified must appear as the Factor1 of a TAG operation somewhere in the program.

Question 188. Which Are The Relational Operators In Rpg?

Answer :

GT, GE, LT, LE & EQ.

Question 189. In 'o' Specs What Is The Opcode For Write?

Answer :

EXCPT.

Question 190. What Does Lokup Does In Tables & Arrays?

Answer :

The LOKUP opcode searches the Factor1 entry in table or array.

Question 191. File Access Opcodes?

Answer :

READ, SETLL, SETGT, READE, READP, READPE CHAIN, KLIST, KFLD, EXCPT & WRITE.

Question 192. What Is Rpg Fixed Logic Cycle?

Answer :

A logic the compiler supplies is called RPG Fixed Logic Cycle.

Question 193. Difference Between Interactive & Batch Job?

Answer :

Batch job begins, runs & continues to execute instructions without human intervention or control while.
Interactive job are user driven.

Question 194. How Can We Run A Batch Job?

Answer :

SBMJOB Command.

Question 195. What Is Arrival Sequence?

Answer :

The records will be accessed the way in which records are added to physical file.

Question 196. How Many Specifications Are There In Rpg/400? What Are They?

Answer :

There are seven specifications exits in RPG/400. They are listed below:

1. Header Specification
2.  File Description specification
3.  Extension specification
4.  Line counter specification
5.  Input specification
6.  Calculation specification
7.  Output specification

    

Question 197. When Do You Use F-spec. Continuation Line ?

Answer :

* In order to refer the named record format as a subfile record format in the program.
* In order to rename the record format of a database file in a program.
* In order to define a named data structure as a file information data structure.

Question 198. What Are The Various Types Of Device Files?

Answer :

Display files, printer files, discket files, tape files etc. ,

Question 199. When Do You Explicitly Open Files And Close Files In An Rpg Program?

Answer :

If you specify the letter ' U ' at column 73-74, you need to be open and close files explicitly in a RPG program.

Question 200. How Do You Know That Records Are Locked?

Answer :

By using a command WRKOBJLCK.

Question 201. What Is The Purpose Of Indicators In Rpg?

Answer :

In order to control the logic flow, we can use indicators in RPG.

Question 202. How Do You Read Data Area In An Rpg Program?

Answer :

With the help of 'IN' opcode, we can access the data area record in to the program.

Question 203. What Are The Different Types Of Data Areas?

Answer :

The different types of Data Areas are general data area, local data area, group data area, pip (program initialization parameter data area) data area.

*General Data Area - It can be created by user implicitely or explicitly
It can be referred by any other jobs.
It can be associated with a library.
It can be created, deleted by the user.

* Local Data Area - It can not be referred by any other job.
It is automatically created and deleted by the system.
It is not associated with any library.

*Group Data Area - It is automatically created and deleted by the system We can access the group data area value through clp.
It is meant for group jobs.

*Pip Data Area - It is meant for pre start jobs.

Question 204. What Are Various Techniques To Pass Parameters From One Program To Another?

Answer :

PLIST, CALL, TFRCTL

Question 205. Which Single Rpg Opcode Performs Both Setll And Reade?

Answer :

CHAIN

Question 206. What Is Term Cua , Saa?

Answer :

Common User Access
System Application Architecture

Question 207. Why Is As/400 Called Object Oriented Machine?

Answer :

Everything on the AS/400 System that can be stored and retrieved is contained in the object.

Question 208. What Is The Version Of Os/400 That We Have?

Answer :

V4R2 (Version 4. 0 Release 2. 0)

Question 209. What Is Ddm ?

Answer :

Distribution Data Management is a function of the OS/400 that allows an application program or user on one system to use database files stored on remote system.

Question 210. What Is An Object?

Answer :

An object is any thing that exists in and occupies space in storage and on which operation can be performed.

Question 211. How Are The Objects Stored On As/400?

Answer :

All objects are stored on AS/400 in a single level storage. In this method all objects are referenced by one virtual address which is translated in to a physical address whether it is an auxiliary storage or main memory.

Question 212. What Is A Library In As/400?

Answer :

A library in AS/400 is an object that serve(acts) as a repository for other objects.

Question 213. Name Few Ibm Supplied Libraries?

Answer :

QGPL, QTEMP, QSYS, QUSRTOOL, QCBL, QRPG

Question 214. What Is Library List ?

Answer :

A list that indicates libraries used for the process and the order in which it has to be searched System identifies it in *LIBL.

Question 215. How Many Libraries Can Be There In Library List ?

Answer :

Total 40 (15 system and 25 application)

Question 216. What Is Folder?

Answer :

A Folder is a named object that is used as a directory for documents and other folders. Folders can be filed with in another folder.

Question 217. Which Of The Following Operations Does Not Zero The Field Flda Defined As 4,0?

Answer :

C MOVE *ZEROS FLDA
C Z-ADD *ZEROS FLDA
C Z-ADD 0 FLDA
C MOVE *ALL'0' FLDA
C SUB FLDA FLDA
C MOVE '0000' FLDA
C CLEAR FLDA
C MOVE *BLANKS FLDA
The last instruction does NOT zero the field FLDA.

Question 218. How Would You Design The Process For A Nightly, High Volume Check Producing Process That Needs To Select Only Records That Are Flagged To Be Processed?

Answer :

With the help of OPNQRYF Clp command, we can select the records from the data base file. The process involves following steps:
Steps: 1. OVRDBF with SHARE (*YES)
2. OPNQRYF
3. CALL the program
4. DLTOVR
5. CLOF

Question 219. Describe The Function Of Setll Operation In Rpg Language?

Answer :

The SETLL operation positions a file at the next record with a key or relative record number that is greater than or equal to key or relative record number specified in factor1.

Question 220. Describe The Function Of Setgt Operation In Rpg Language?

Answer :

The SETGT operation positions a file at the next record with a key or relative record number that is greater than key or relative record number specified in factor 1.

Question 221. What Is The Purpose Of Level Check Parameter In A Physical File?

Answer :

Specifies whether the level identifiers of the record formats in the physical file are checked when the file is opened by the program.

Question 222. Define A Job Queue?

Answer :

Job queues are queues of batch jobs waiting to be processed.

Question 223. Define A Output Queue?

Answer :

Output queues are queues of jobs waiting to be printed.

Question 224. What Is The Function Of Cpysplf Command?

Answer :

It copies the spooled file to the data base file.

Question 225. What Is The Function Of Cpyf Command?

Answer :

To copy the data from the one file to another.

Question 226. What Is The Function Of Crtdupobj Command?

Answer :

To create the replica from the original object.

Question 227. Define Subsystem?

Answer :

Subsystem is nothing but it provides specialized environment to complete the execution of jobs.

Question 228. What Are Different Types Of Substems?

Answer :

QBATCH, QINTER, QSPL, QCMN, QCTL, QBASE.

Question 229. Define A Batch Job?

Answer :

* A user request the job.
* The job is created (job name is assigned, job attributes are allocated)
* The job is placed on a job queue
* The sub system QBATCH takes the job from job queue and starts it.
* Output generated by the batch job is placed on an output queue.
* The spool sub system prints the output on the output queue.

Question 230. Describe About Query/400?

Answer :

Query/400 is a licensed program that uses a query to analyze and select the information contained in the data base files and create a query report.
A query report can be:
* displayed on a workstation (screen)
* printed
* stored in another database file.

Question 231. What Is The Clp Command To Access A Query/400?

Answer :

WRKQRY

Question 232. What Is The Purpose Of Overrides?

Answer :

The basic purpose of Overrides is to temporarily change the attributes of a file. So you don't have to create permanent files for every combination of attributes your application might need. Overrides gives you the flexibility to use existing model files and dynamically change their attributes.

Question 233. Define Data Structure?

Answer :

Data structures are specified in the Input specifications of an RPG/400 program to define an area in storage and layouts of related sub fields.

Question 234. What Is The Purpose Of Data Structure?

Answer :

* Divide a field in to sub fields
* Change the format of a field
* Group non-contiguous data in a contiguous format
* Define an area of storage in more than one format
* Define Multiple occurrences of data structures.

Question 235. What Is The Purpose Of Dynslt Keyword?

Answer :

This is a file level keyword used in a logical file. If you specify this in a file level, the system doesn't perform record selection until the program reads file. Then on the Select/Omit criteria, it selects the records from the specified file.

Question 236. When Would You Prefer Logical File Than Opnqryf?

Answer :

The physical file you are working with very large, creating and using a logical file will allow an application to perform faster than using an open query file. Since access paths created by open query files are temporary, applications that use an access path frequently will be more efficient using a logical file, since the access path will not have to be rebuilt every time the file is open.

Question 237. What Does Opcode Post Do?

Answer :

Puts information in INFDS.

Question 238. What Does The Opcode Free Do?

Answer :

The FREE operation removes a program from the list of activated programs, frees static storage and ensures program initialization (first cycle processing) the next time program is called. It does not close file or unlock data area.

Question 239. How Do You Use Exceptional Write In C Specs?

Answer :

Using EXCPT opcode.

Question 240. How Do You Use Commitment Control In Rpg Program ?

Answer :

Using COMIT operation. Makes all changes to the files that have been specified in output operation since the previous COMIT or the begining of operations under commitment control(if there has been no previous COMIT or ROLBK operation).

Question 241. What Is Scan And Xlate?

Answer :

SCAN operation scans a character string (base string) contained in factor 2 for a substring (compare string ) contained in factor 1.

XLATE operation translates characters in source string (factor 2 ) to the from and to strings (factor 1 ) and put into the result field.

Question 242. What Does 'sr' In Columns 7-8 Of C Specs Mean?

Answer :

Calculation operation is a part of RPG subroutine.

Question 243. What Does Check Opcode Is Used?

Answer :

The check operation verifies that each character in the base string (factor 2) is among the character indicated in the comparator string (factor 1).

Question 244. How To Read Database Records Without Locking Them?

Answer :

Put 'N' in position 53 of C specs.

Question 245. What Opcode Will Be Used To Test The Zone Of A Character Field?

Answer :

TESTZ

Question 246. What Opcode Could Be Used To Test An Alphanumeric Field For All Numeric Values?

Answer :

TESTN

Question 247. When Is A Tag Statement Used In Rpg?

Answer :

It is used as Label.

Question 248. What Is The Length Of A Variable In Rpg?

Answer :

6 Characters.

Question 249. What Is Match Field Indicator?

Answer :

Matching record indicator is seton when all the matching fields in the record of a secondary file matches with all the matching fields of a record in a primary file.

Question 250. Can You Specify A Display File To Be Used In The Following Modes Input, Output, Or Combined Modes ?

Answer :

Yes.

Question 251. What Is Externally Described File ?

Answer :

All information about the fields is specified in DDS and the RPG program can use them with in the program.

Question 252. What Is A Program Described File In Rpg?

Answer :

The field name and length of the fields are defined with in the RPG program.

Question 253. Can A Indexed File Be Accessed In Arrival Sequence In Rpg Program?

Answer :

Yes.

Question 254. What Is A Primary File?

Answer :

It is used in RPG Program Cycle to automatically read records in a cycle.

Question 255. How Do You Specify Page Overflow Indicator For Printer Files In Rpg?

Answer :

Specify an indicator in position 33-34 of F specification.

Question 256. Give Three Main Purposes Of File Specification ?

Answer :

To define files, to describe the files, to assign the files to specified devices.

Question 257. Define A Shared Access Path?

Answer :

To share the open data path by various programs in a same job.

Question 258. What Is *inzsr Used For?

Answer :

It is special type of RPG/400 subroutine, which is executed automatically at beginning of the program. It is a good place to code initializes the variables.

Question 259. How Can You Execute A Command From Within An Rpg Program Without Calling A Clp Program?

Answer :

By calling QCMDEXC application program interface we can execute a CL command with in an RPG program.

Question 260. What Is The Difference Between Access Path And Dynamic Select?

Answer :

Dynamic select occurs whenever the program reads file. But access path occurs before the file is read (but not necessarily). Because access path maintenance performed on the file.

Question 261. A Query Can Be Run In Which Mode?

Answer :

Batch & Interactive

Question 262. To Add A File To The 'file Selection' Option Of A Query, The Function Key To Be Pressed Is?

Answer :

F9

Question 263. Which Are The Query Selection Criteria, Which Can Be Given In A Query?

Answer :

LIST

Question 264. A Query Can Be Displayed Without Saving It?

Answer :

true

Question 265. Which Type Of Object Is Used In Db2/400?

Answer :

*FILE

Question 266. Records Can Be Read/update/deleted With Which File?

Answer :

Simple Logical File & Physical File.

Question 267. An Access Path May Be In Which Sequence?

Answer :

It can be in Arrival & Keyed sequence.

Question 268. Db2 Is A Type Of Database?

Answer :

It is an Integrated RDBMS.

Question 269. Which Are The String Manipulation Opcodes?

Answer :

TESTN, SCAN, CHECK, CHECKR, SUBST & CAT

Question 270. Which Are Control Break Logic Indicators?

Answer :

L1 – L9.

Question 271. How Many Maximum Spaces Could Be Given In O Specs?

Answer :

3

Question 272. What Are Members?

Answer :

Members are separate entities within a database file & they are components of As/400 object.

Question 273. What Is Full Form For Dds?

Answer :

Data Description Specification

Question 274. How Does Union File Maintains Record Formats?

Answer :

1 Record format for each PF

Question 275. A Multiple Format Logical File Is Also Known As?

Answer :

Union File

Question 276. A Join Logical File Has How Many Record Formats?

Answer :

1

Question 277. Space & Skip Are Which Level Keywords?

Answer :

Field & Record

Question 278. What Is The Use Of Data Structures?

Answer :

1.Dividing a field into sub fields.
2.Changing the format of a field.
3.Grouping non-contiguous data in a contiguous format.
4.Defining an area of storage in more than 1 format.

Question 279. How To Run Other Job When One Job Is Active?

Answer :

Change the priority or rename the job.

Question 280. What Is The Error If We Don't Get Login Screen?

Answer :

There is some problem with subsystem.

Question 281. What Does Vldcmdkey Means?

Answer :

Valid Command Key.

Question 282. Difference Between Call & Sbmjob?

Answer :

CALL performs interactively job while SBMJOB performs batch job.

Question 283. What Is The Maximum Number Of Records You Can Specify In A Display File?

Answer :

1024

Question 284. How Can A Screen Field That Has Changed Since The Last Output Operation Be Detected ?

Answer :

Attach the MDT (modified data tag) attribute to the field, to detect whether field has been changed as a result of user input.

Question 285. What Would Be The Effect On The Field Where Reverse Image, Underline And Highlight Display Attributes Were Active?

Answer :

The result is same as if you had specified ND.

Question 286. What Is The Use Of Dspatr(mdt) Keyword?

Answer :

Sets on the modified Data Tag of the field. The Data Tag detect whether the field has been changed as a result of user input.

Question 287. If Dspatr(pc) And Csrloc Were Specified For A Format, Which Keyword Would Have Priority?

Answer :

CSRLOC gains priority.

Question 288. Can Error Messages As A Result Of A Comp, Range Or Values Keyword Be Overridden?

Answer :

Yes, through CHKMSGID keyword.

Question 289. What The Purpose Of Ovrdta, Ovrata Keywords?

Answer :

1.OVRDTA keyword (field or record level) can be used to override the existing data contents of a field or record already on the display.
2.OVRATA keyword (field or record level) can be used to override the existing display attributes of a field or record already on the display.

Question 290. How Can A Message From A Message File Appear As A Constant On The Screen?

Answer :

By using MSGCON (message constant) keyword.

Question 291. In Conjunction With What Other Keyword Must Ovrdta And Ovrata Be Used?

Answer :

PUTOVR keyword must used.

Question 292. What Is The Purpose Of The Indara Keyword?

Answer :

This File-level keyword is used to remove option and response indicators from the buffer and places them in 99-byte separate indicator area.

Question 293. Explain The Purpose Of Keep And Assume Keywords?

Answer :

KEEP: Keep the display from being deleted when the display file is closed.

ASSUME: It is used to specify that the OS/400 program is to assume that this record is already shown on the display when this file is opened.

Question 294. Explain The Use Of Dftwrt Display Keyword?

Answer :

No records will be displayed until there is any I/O operation.

Question 295. What Is The Purpose Of Frcdta Keyword ?

Answer :

Immediately display a record format without waiting for the next I/O operation.

Question 296. What Keyword Must Be Used With Protect Keyword?

Answer :

OVERLAY

Question 297. What Is Subfile?

Answer :

Subfile is group of records of same record format and can be read from or write to the display in a single operation.

Question 298. What Are All The Contents Of Subfile?

Answer :

Subfile Record Format, Subfile Control Record Format, Relative Record Number, Subfile Record Number, Associated Subfile Keywords.

Question 299. What Are The Two Record Formats A Subfile Contain ?

Answer :

Subfile record forma (SFL), and subfile control record forma (SFLCTL).

Question 300. What Is The Maximum Number Of Subfiles That Can Be Specified In A Display File,

Answer :

512

Question 301. Maximum Number Of Subfiles That Can Defined In A Rpg Program For One Display File Is?

Answer :

24

Question 302. Maximum Number Of Subfiles That Can Be Active For A Single File Is?

Answer :

12

Question 303. Can More Than One Subfile Record Be Displayed On One Line?

Answer :

Yes, by using SFLLIN keyword.

Question 304. How Do You Specify The Number Of Records To Roll In A Subfile?

Answer :

Use SFLROLVAL keyword in DDS along with number, which specifies the number of records to scroll at a time.

Question 305. How Will You Display A Particular Page In Subfile?

Answer :

Move a valid relative record number (RRN) in the field specified using SFLRCDNBR keyword in DDS.

Question 306. How To Pick Up The Changed Records Every Time In A Subfile After The First Change Made?

Answer :

Seton SFLNXTCHG keyword indicator and update the subfile record.

Question 307. What Is The Use Of Sflend Keyword?

Answer :

By specifying this keyword, the Bottom/More message could be displayed at end of screen.

Question 308. How To Toggle Between Single Line And Multi - Line Display Of A Particular Record In A Subfile?

Answer :

Using SFLDROP keyword.

Question 309. Explain The Difference Between Defining Subfile And Message-subfile?

Answer :

Subfile record is defined by SFL keyword, where as Message subfile is defined by SFLMSG keyword.

Question 310. What Are The Different Types Of Variables Available In Cl?

Answer :

DEC, CHAR, LGL

Question 311. What Is The Difference Between Sflclr And Sflinz?

Answer :

SFLCLR : It clears the subfile.

SFLINZ : First it clears the subfile and initiliazing the numeric variables with zeros and alphanumeric variables with characters.

Question 312. Define The Purpose/use For Sflrna?

Answer :

Using this, we can make specified subfile record format inactive.

Question 313. When Would You Use Or Not Use This Approach?

Answer :

It is the most desirable method in building a real time applications. We can use at all the times.

Question 314. How Can You Detect And Handle A Record Lock Situation?

Answer :

If you try to read the locked record, we can get system defined message i. e. , the program will ended abnormally. With the help of File Information Data Structure we can handle record lock situation. Generally it will happen, when the same file of type " U" used in different programs.

Question 315. How Can You Detect Overflow For A Print Program That Prints Multiple Lines Per Cycle?

Answer :

You specify the indicators OA through OG and OV in 33 - 34 columns in a printer file. This indicator automatically set on whenever overflow occurs on a type of page.

Question 316. What Is The Purpose Of The "n" In The Following Calculation Specification?

Answer :

C KEY CHAIN FILE N 99.If you specify 'N' in 53rd position, the record will not be locked if you try to read the locked record. It is a way of avoiding the record lock.