AS400 Interview Questions

by Rupa.R, on Sep 9, 2022 5:19:43 PM

Interview Questions (48)

Q1. What does ‘AS’ in AS400 stands for?

Ans: Application system.

Q2. What is ‘LPAR’?

Ans: OS/400 Version 4, introduced a feature LPAR (Logical PARtitioning) which facilitates running multiple operating systems simultaneously on one IBM System i unit ensuring that one OS doesn’t interfere other’s system resources/memory.

Q3. What is library is AS400? What are the types of library?

Ans: When we execute a command or call a program, the  AS/400  must know where to find the command or program and the answer is library. A Library is a collection of objects. QSYS is the only library that contains other library. QSYS is the root library where the entire user defined/ system defined library is created. System supplied libraries begin with the letter "Q" or "#".

Library list types:

System library: All IBM supplied library e.g. QSYS, QHLPSYS, QUSRSYS…

Product Library: Whenever Ibm product is used it is added to the library automatically and is removed itself when the job completes.

Current Library: Current library is the working library i.e. all the work done by you is stored in current library.

User Library: Non-IBM supplied i.e. created by the user.

Q4. Which library gets first loaded into the system when we login?

Ans: QSYS

Q5. Is QGPL a user library or system library?

Ans: It’s a user library.

AS400 Training

Q6.How can we see all the objects and its sizes in a library?

Ans: By using the command DSPLIB.

Example:  DSPLIB IROBO1

It gives you the information of all objects that resides in the library with it size.

Display Library

Library  . . . . . . :   IROBO1          Number of objects  . :   8

Type . . . . . . . . :   PROD            Library ASP number . :   1

Create authority . . :   *EXCLUDE        Library ASP device . :   *SYSBAS

Type options, press Enter.

5=Display full attributes   8=Display service attributes

Opt  Object      Type      Attribute               Size  Text

PRINT1PGM   *PGM      RPGLE                 131072  rpgle program for pri

ACCOUNT     *FILE     PF                     49152  ACCOUNT RELATED INFOR

PRINT1      *FILE     PRTF                    4096  PRINTER DDS RLU GENER

QCLSRC      *FILE     PF                      8192  Sources CL-Programs

QDDSSRC     *FILE     PF                      8192  DDS-Sourcen

QRPGLESRC   *FILE     PF                     69632

QRPGLESRC2  *FILE     PF                     65536

QRPGSRC     *FILE     PF                      8192  SOURCE PHYSICAL FILE

Bottom

F3=Exit   F12=Cancel   F17=Top   F18=Bottom

Q7. What is source physical file?

Ans: Source physical file is a file which contains the sources of different types of objects. There can be up to 32768 members. Source physical file is an object. But the source member is not an object. When we compile the member, the object is created for that source. Command used is CRTSRCPF.

CRTSRCPF FILE(IROBO1/QRPGSRC) RCDLEN(112) TEXT('SOURCE PHYSICAL FILE’)

Q8. How to see all members of a file?

Ans: By using the command shown below:

DSPFD FILE(IROBO1/QRPGLESRC) TYPE(*MBRLIST)

Q9. How to see all record formats used in a file?

Ans: By using the command shown below:

DSPFD FILE(IROBO1/QRPGLESRC) TYPE(*RCDFMT)

Q10. How to change the record size of a physical file?

Ans: By using the command below:

CHGPF FILE(AMITNEM/OBJ) SRCFILE(AMINEM/QDDSSRC) SRCMBR(OBJ_SRC)

We change the highlighted part to change the size of a file.

Change Physical File (CHGPF)

Type choices, press Enter.

Physical file  . . . . . . . . .                 Name

Library  . . . . . . . . . . .     *LIBL       Name, *LIBL, *CURLIB

System . . . . . . . . . . . . .   *LCL          *LCL, *RMT, *FILETYPE

Source file  . . . . . . . . . .   *NONE         Name, *NONE

Library  . . . . . . . . . . .                 Name, *LIBL, *CURLIB

Member size:

Initial number of records  . .   *SAME         1-2147483646, *NOMAX, *SAME

Increment number of records  .   *SAME         0-32767, *SAME

Maximum increments . . . . . .   *SAME         0-32767, *SAME

Q11. How can we arrange duplicate records in a file?

Ans: For this we will use file level keywords FIFO/LIFO/FCFO in the physical file.

FIFO: The duplicate key records will retrieved in first in first out order.
LIFO: The duplicate key records will retrieved in last in first out order.
FCFO: The duplicate key records will retrieved in first changed first out order.

Q12. How to refer another file to define a new field in a physical file?

Ans: below is an example, we are going to use the file REFER to get the field definition for new file.

USE OF REFERENCE                                                  

Columns . . . :    1  71           Browse                        AMINEM/DDSSRC

SEU==>                                                                   REFER

FMT PF .....A..........T.Name++++++RLen++TDpB......Functions++++++++++++++++++

*************** Beginning of data *************************************

0002.00      A          R REF

0003.00      A            RAC1           2P 0       COLHDG('LEVEL ID')

0004.00      A            RAC2           3P 0       COLHDG('ORG CODE')

0005.00      A            RAC3          12P 0       COLHDG('ACCOUNT NUM')

0006.00      A            RAC4           3A         COLHDG('ACCOUNT CURRENCY')

0007.00      A            RPOSTCODE      2P 0       COLHDG('POST CODE')

0008.00      A            RCOUNTRY       3P 0       COLHDG('COUNTRY CODE')

0009.00      A            RNAME         20A         COLHDG('NAME')

0010.00      A            RDATE          3P 0       COLHDG('DATE')

****************** End of data ****************************************

Now we can refer the file ‘REFER’ to take the field definition in the new file.

Columns . . . :    1  71           Browse                        AMINEM/DDSSRC

SEU==>                                                                  USEREF

FMT PF .....A..........T.Name++++++RLen++TDpB......Functions++++++++++++++++++

*************** Beginning of data *************************************

0002.00      A                                      REF(REFER)

0003.00      A          R USEREF

0004.00      A            ACCLVL    R               REFFLD(RAC1 REFER) >>>>>>  field name and

0005.00                                             ALIAS(ACC_LVL_ID)     referred file name

0007.00      A            ACCORG    R               REFFLD(RAC2 REFER)

0008.00                                             ALIAS(ACC_ORG_CODE)

0009.00      A            ACCNUM    R               REFFLD(RAC3 REFER)

0010.00                                             ALIAS(ACC_NUM)

0011.00      A            ACCCUR    R               REFFLD(RAC4 REFER)

0012.00                                             ALIAS(ACC_CUR)

0013.00      A            ACCNAME   R               REFFLD(RNAME REFER)

0014.00                                             ALIAS(ACC_NAME)

****************** End of data ****************************************

Q13. Can LEVEL CHECK ERROR occur if we do CHGPF?

Ans: It depends on the value that we have set for LVLCHK (Record format level check) attribute. If its value is *YES then the record format level identifier is checked when the file is opened and if it doesn’t match it throws the error. If its value is *NO, then the record format level identifier is not checked, hence no error.

Q14. What is logical file in AS400? What are the types of logical file?

Ans: Logical file

  • Logical file does not occupy any memory.
  • One or more logical file can be derived from a single physical file.
  • It simply contains the record selection definition and when accessed retrieves the records from the physical file to which it refers.
  • A logical file can contain up to 32 record formats.
  • It selects records dynamically. It cannot exist without a physical file.
  • We can filter the data with criteria by using select and omit command.
  •  A logical file does not contain any data but provides the ‘VIEWS’ of the data to satisfy end-user’s needs.

Q15. What is logical file in AS400? What are the types of logical file?

Ans: Logical file

  • Logical file does not occupy any memory.
  • One or more logical file can be derived from a single physical file.
  • It simply contains the record selection definition and when accessed retrieves the records from the physical file to which it refers.
  • A logical file can contain up to 32 record formats.
  • It selects records dynamically. It cannot exist without a physical file.
  • We can filter the data with criteria by using select and omit command.
  •  A logical file does not contain any data but provides the ‘VIEWS’ of the data to satisfy end-user’s needs.

Ü  Types of Logical file

There are two types:

1)      Non-join logical file

2)      Join logical file

 1)  Non-join logical file

Non-join logical files can either be a simple logical file, which contains only one record format or a multiple record format logical file, which contains more than one Record format.

Logical files can be derived from 1 to 32 physical files and so a logical file can have a maximum of 32 record formats.

i) Single record format Non-join logical file:

If a logical file is derived from single physical file it is called simple logical file.

Columns . . . :    1  71           Browse                        AMINEM/DDSSRC

SEU==>                                                               MULTIFRMT

FMT LF .....A..........T.Name++++++.Len++TDpB......Functions++++++++++++++++++

*************** Beginning of data *************************************

0002.00      A          R ACCOUNT                   PFILE(AMINEM/ACCOUNT)

0003.00      A          K ACCOUNTNUM

0005.00      A          K ACCURRENCY

ü) Multiple record format Non-join logical file:

  • Multiple record non-join logical files will select records from 2 or more physical files by referring to only one logical file.
  • Each record format is always associated with one or more physical file.
  • The same PF can be used in more than one record format.

Columns . . . :    1  71           Browse                        AMINEM/DDSSRC

SEU==>                                                               MULTIFRMT

FMT LF .....A..........T.Name++++++.Len++TDpB......Functions++++++++++++++++++

*************** Beginning of data *************************************

0002.00      A          R ACCOUNT                   PFILE(AMINEM/ACCOUNT)

0003.00      A          K ACCOUNTNUM

0005.00      A          K ACCURRENCY

0006.00      A          R TRANS                     PFILE(AMINEM/TRANS)

0007.00      A          K TACCOUNT

0008.00      A          K TCURRENCY

****************** End of data ****************************************

Q16. What is DYNSLT?

Ans:   DYNSLT: Use this file-level keyword to indicate that the selection and omission tests specified in the file (using select/omit specifications) are done at processing time. This keyword specifies dynamic select/omit rather than access path select/omit.

Only a Physical file contains data. Logical files just contain pointers for processing the data in a specific sequence and/or subset of data.
When a record is added/changed/deleted in a physical file, the system has to put a lock on it and then go out to check and update any logical files before it can release the lock. While the amount of time to do this is hardly measurable, it can be significant if massive batch updates are done to a file.
If you are using the Select/Omit option in your DDS and using DYNSLT, the above process does not need to be done at record update time.
Where this is beneficial is when your selection process includes almost all the records in the file. Now when you process using DYNSLT, it will read all the records in the file, but do the selection of which records to process at that time rather than having done all the maintenance ahead of time.

Q17. What is the Difference between access path and Dynamic select?

Ans: Dynamic select occurs whenever the program reads file. But access path occurs before the file is read (but  not necessarily).

Q18. What is the use of JDUPSEQ in AS400?

Ans: JDUPSEQ

This join–level keyword is used to specify the order in which records with duplicate join fields are presented when the JLF is read.

The format for this keyword is:

JDUPSEQ (Sequencing field-name [*DESCEND])

i) This keyword has no effect on the ordering of records with unique keys.

ü)If *DESCEND is not specified then the default is sequencing in ascending order.

Bottom of Form

Q19. What is the use of JDFTVAL in AS400?

Ans: JDFTVAL

  • When this file-level keyword is used the system provides default values for all for fields when a join to a secondary file does not produce any records.
  • If this keyword is not specified a record in the primary file for which there is no corresponding record in the secondary file is skipped.

Q20. What is the difference between non-join logical files and join logical files?

Ans:

Non join logical file Join logical file
We can insert or delete or update records using non-logical file. Insertion, updating or deletion of records is not possible in join logical files.
DFU can be used to display non-join logical file. DFU is not available
1-32 record format is specified Only one record format can be specified
Commitment control is used Commitment control cannot be used.

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Q21. What is the difference between physical file and logical file?

Ans:

                Physical file Logical file
1. Occupies the portion of memory. It’s containing data. Does not occupy any memory space. Does not contain any data.
2. A physical file contains one record format  A logical file can contain up to 32 record formats.
3.Can be exist even without LF Can’t exist without PF
4. If you delete a LF, the PF can’t be deleted If you delete a LF, the PF can’t be deleted
5.CRTPF command is used to create such object CRTLF command is used to create such type object

 

Q22. What are the record format field mapping options in CPYF?

Ans: Record format field mapping (FMT)

*MAP

Fields with the same name in the from-file and to-file record formats are copied, and any fields in the to-file that do not exist in the from-file format are set to the default value specified on the DFT keyword for the data description specification (DDS) of the to-file or zero for numeric fields, blanks for character fields, current date/time for date/time fields, or null value for null-capable fields.

If *MAP is specified, *DROP can also be specified.

*DROP

This value must be specified for field-level mapping if any of the field names in the from-file record format do not exist in the to-file format. If *DROP is specified, *MAP can also be specified. When *DROP is specified, all the field names that exist in both record formats must have the same attributes and relative positions in the from-file and to-file record formats, or *MAP must also be specified. Null values are copied.

*NOCHK

 If the record formats of the database files are different, the copy operation continues despite the differences. Record data is copied directly (left to right) from one file to the other. FMTOPT (*NOCHK) is required when copying all record formats from a logical file with multiple formats (when RCDFMT (*ALL) is specified) to a physical file that is of the same type (source or data) as the from-file.

 *CVTSRC

This value is used to copy between database files, from a source file to a data file, or from a data file to a source file. It is valid only when the from-file and to-file are different types (source and data).

Q23. What is the Difference between CRTDUPOBJ and COPYF?

Ans: In CRTDUPOBJ for a logical file the created duplicate file will be also logical file and for a physical file the created file will also be a physical file. Even the record format identifier will also be the same. While in case of COPYF, if we are copying a logical file then the created file be a physical file not a logical file.

Q24. What is access path in AS400?

Ans:

Access path

i)  Access path describes the order in which records are to be read.

ii) Access paths can be kept on the system permanently (such as physical or logical file) or temporarily.

üi)  OPNQRYF command may create a temporary access path for use one time, and then discard the access path.

Q25. What are the types of access path? How to change the access path of a file?

Ans: Types of Access Path

  • Arrival sequence access path
  • Keyed sequence access path
  • Arrival sequence access path

i) Sequentially, where each record is taken from the next sequential physical position in the file.

ü)Directly by relative records number, where the record number is identified by its position from the start of the file.

  • Keyed sequence access path

i) It is based on the contents of the key fields as defined in DDS. This type of access path is updated in the                                contents of a key field is changed.

ü) There are three ways of bounding the access path:

Immediate

Rebuild

Delayed

Q26. What is the default access path of a file?

Ans: If you do not specify the type of maintenance for a file, the default is immediate maintenance.

Q27. What is the maximum number of fields that can be in a file?

Ans: Maximum no of fields included in a PF is 8000.

Q28. Maximum no of parameter passed in a RPG?

Ans: Maximum no of parameter passed in RPG is 255.

Q29. Maximum no of parameter passed in a CL?

Ans: Maximum no of parameter passed in CL is 40.

Q30.What is compile time array in AS400? Give example of compile time array.

Ans: Compile time array

  • The compile time array means the elements of the array will be loaded before the execution of the programs i.e. at compile time.
  • The value will be static.
  • We must declare in keyword command DIM (), CTDATA (), and PERRCD ().

DIM() represents the size of the array.

CTDATA() represents that it is compile time array.

PERRCD() represents the number of entries in one array record.

Dim = row i* col j

e.g. PERRCD=2, NO. OF ROWS=3, THEN DIM = PERRCD*NO. OF ROWS=6

  • We mention the array element just after the last statement of the program.

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Q31. What is array in AS400? What are the types of array?

Ans: Array is collection of elements of same data type.

Types of Array

1)      Compile time array

2)      Pre-runtime array

3)      Run time array

Q32. What is Pre run time array in AS400? Give example of Pre run time array.

Ans: Pre-runtime array

  • There are some limitations of compile time array. E.g. If we want to change the value of an array element, we need to make changes in the program source code where the array’s element is defined and then recompile the program.
  • In pre-runtime array, we maintain the array element in separate file. Hence, if we are making any change in array element we can just change this file containing the array element; we don’t need to compile the source program again and again as in compile time array.
  • The file that stores the array element must be defined in the F specs with ‘T’ as File Designation entry.
  • Record length is also a mandatory entry in F spec.

 length of record = Perrcd *size of 1 element

Q33. What is data structure in AS400? What is the use of data structure?

Ans: DATA STRUCTURE 

  • Data structure in general means a structure of different data type.
  • Data structure is specified in the Input Specification of an RPG 3 Program whereas in RPG 1V we specify it in 'D' specification.
  • Data Structure is used-
  1. To break fields into subfields
  2. To Group fields
  3. To change the format of the field
  4. To Group non-contiguous data into contiguous format
  5. 5.To convert data.

Q34. What are the types of data structure in AS400? Give example of data structure?

Ans: Below are the types of data structures in as/400:

Q35. What is program status data structure(PSDS) in AS400? Give example if PSDS.

Ans: A program status data structure (PSDS) can be defined to make program exception/error information available to the program so that the necessary action can be taken for the unhandled exception. The exception /errors can beDivide by zero, array index out-of-bound, Invalid Date, Time or Timestamp value. The PSDS must be defined in the main source section; therefore, there is only one PSDS per module.

Q36. What is file information data structure(INFDS) in AS400? Give example if INFDS.

Ans: A file information data structure (INFDS) can be defined for each file to make file exception/error and file feedback information available to the program.

Q37. How can we create subsystem in AS400?

Ans: Steps of creating the subsystem

i)Create Subsystem description (CRTSBSD)

First of all we create subsystem description as below:

CRTSBSD   SBSD (AMINEM/MYSBSD) POOLS ((2 *BASE)) MAXJOBS(2)  TEXT('My  subsystem description')

ii)Create Job queue (CRTJOBQ)

Then we create a job queue as below:

CRTJOBQ   JOBQ (AMINEM/MYJOBQ) TEXT('My job queue')

iii)Add Job Queue Entry (ADDJOBQE)

Once the job queue is created, then we attach the (ADDJOBQE) command, as follows:

ADDJOBQE SBSD (AMINEM/MYSBSD) JOBQ (AMINEM/MYJOBQ) MAXACT (1)

MAXACT denotes the number of the jobs that can be process at the same time.

iv)Create Class (CRTCLS)

Class defines the run time attribute e.g. Run priority, Time slice, Default wait time, Maximum temporary storage etc.

CRTCLS    CLS(AMINEM/MYCLS) RUNPTY(40)

v)Add Routing Entry (ADDRTGE)

ADDRTGE SBSD(AMINEM/MYSBSD) SEQNBR(9999) CMPVAL(*ANY) PGM(SYS/QCMD) CLS(AMINEM/MYCLS)

vi) Start Subsystem (STRSBS)

STRSBS SBSD(AMINEM/MYSBSD)

Q38. What is compiler directive in AS400? Give example of compiler directive.

Ans: Compiler directive

  • Compiler directive is an instruction (directive) given to the compiler, to perform some specific task during compilation or to generate customize compiler listing report after compilation.
  • Compiler directive serve many purposes like it is used to control the heading information in compiler listing, to control the spacing of the compiler listing, to include source statement from other source member, to do a free form calculation in our rpgle program, to control the source records selection/omission based on some condition etc.
  • Compiler directives are:

(1)     /FREE... /END-FREE

(2)      /TITLE

(3)     /EJECT

(4)     /SPACE

(5)     /COPY or /INCLUDE

(6)     /IF……/ELSEIF…. /ELSE…… /ENDIF

(7)     /EOF

Q39. What is data queue in AS400? Give example of data queue.

Ans: Data Queue

  • It is used for making asynchronous communication between the two jobs. If we are sending data from one job to another using data queue using QSNDDTAQ API, but at that time the receiver job is not active, then the data will be there in the queue and whenever the receiver job becomes active, it retrieves the data using the QRCVDTAQ API.
  • It facilitates fastest communication compared to when we use other things to communicate like dataarea, message queue or database files.
  • It can yet be used for synchronous communication also or within the same job.
  • We use APIs to make communication e.g. QSNDDTAQ, QRCVDTAQ.
  • The content of the data queue is messages in free format.
  • The messages on the data queue is stored in *FIFO, *LIFO or *KEYED. *KEYED means the messages can be retrieved using key value associated with the messages. In case of *KEYED we need to mention key length also.
  • First create the data queue by using CRTDAQ command
  • Data query is nothing but a queue in which are program can send a data and other program or the same program can receive the program. QSNDDTAQ is stored in QSYS.
  • We can create data queue on local system or on remote system by making the data queue type as *DDM. By default it will be *STD. In case of DDM data queue, we need to mention Remote data queue name(RMTDTAQ) and remote system name(RMTLOCNAME) also as parameter.
  • QSNDDTAQ

By using this command sent data same / another program.

QSNDDTAQ   PARM (QUEUE-NAME LIB  &LEN  &DAT)

  • QRCVDTAQ

By using this command receive data same /another program

QRCVDTAQ   PARM (QUEUE-NAME LIB &LEN &DAT &WAIT)

Q40. What is FTP in AS400? What are the FTP commands in AS400?

Ans:  We are using FTP in as400 to send and receive data from/to remote system.

Below are the basic FTP commands in the transfer:

  • LCD directory-name:This command is used to change the Local system directory to directory-name.

e.g.  

LCD Library-name

LCD C:\folder\onpc\where\stuffis

LCD “C:\Program Files”

  • CD  directory-name:This command is used to change the Remote system directory to directory-name.

e.g.

CD Library-name

CD C:\folder\onpc\where\stuffis

CD “C:\Program Files”

  • GET library/source-physical-file. Member-name:This command is used to fetch a file from remote system.

e.g.

GET AMINEM/QRPGLESRC.DSPPGM

This can be used to fetch save-file also:

GET SAV005

If Member SAV005 in file SAV005 in library QGPL already exists. Specify

REPLACE as a subcommand option as shown below.

GET SAV005 (REPLACE

  • MGET:It is used to fetch multiple file from remote system, GENERIC IS ALLOWED.

e.g.

MGET aminem.*  aminem1.* 

  • PUT:To send a file to remote system

e.g.

PUT RPGSRC.ADDCL  RPGSRC11.ADDCL1

  • MPUT: To send multiple files to remote system

It is used to fetch multiple file from remote system, GENERIC IS ALLOWED.

e.g.

MGET aminem.*  aminem1.* 

  • NAMEFMT (name formatting):Its value can be 0 or 1, it has been explained below.
  • QUOTE SITE NAMEFMT 

i)  For working with standard library objects

ü)  File identifiers have three components: Library, File and member.

üi) Library and file components are separated by the / delimiter.

iv)File and member components are separated by the . delimiter.

v)Syntax: Library/file.member

Example

 PUT something.txt QGPL/QCLSRC.TEST

CD QGPL

PUT something.txt QCLSRC.TEST

  • QUOTE SITE NAMEFMT 

i)For working with IFS objects (ie. All objects)

ü) Directory levels separated by the / delimiter.

üi)Database files use format: /QSYS.lib/Libname.lib/Fname.file/Mname.mbr

iv)Documents (files) stored in folders use format: /QDLS/folder/document.ext

v)CD / (puts you in the root IFS folder)

  • QUIT

Ends the FTP session with the remote computer and exits ftp.

  • Bye

Ends the FTP session with the remote computer and exits ftp.

  • ASCII

i) It Sets the file transfer mode to ASCII (Note: this is the default mode for most FTP programs)

ü)ASCII  is a character-encoding scheme originally based on the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text. Most modern character-encoding schemes are based on ASCII, though they support many additional characters.

e.g.

ftp> ascii

ftp> put d:\path1\filename1.txt

200 PORT command successful.

Opening ASCII mode data connection for filename1.txt

226 Transfer complete

  • Binary

i)  It Sets the file transfer mode to Binary

ü) the binary mode transfers all eight bits per byte and must be used to transfer non-ASCII files or non-standard files e.g. zip file, tar file, image file, .DAT file, save file, executable files, sound files, graphic files etc.

e.g.

ftp> binary

ftp> put d:\path1\filename1.zip

200 PORT command successful.

Opening BINARY mode data connection for filename1.zip

  • Quote

It will send an argument to the remote FTP Server. This statement is similar in purpose as the "LITERAL" statement.

  • Site

This parameter is used at the client system to transfer a function (via the LITERAL or QUOTE statement) to the host site.

e.g. 

We can change the naming format to 0 with the command as shown below.

  • Open

  It opens a new FTP connection with another system.  

e.g.

Open system-name[teaserbox type="5" img="2803" title="Interested in Learning IOT" subtitle="Join myTectra" link_url="http://www.mytectra.com/iot-training-in-bangalore.html" target="blank"]

Q41. What are the journaling commands?

Ans: APYJRNCHG: Uses the journal entries to apply changes that have occurred since a database file was saved or some other specified time.

CHGJRN: Use this command to change the attributes of a journal or to attach new journal receivers to a journal.

CMPJRNIMG: This command compares and lists the difference between the before-image and after-image of a record, or between the current after-image of a record and the previous after-image of the record.

CRTJRN: Use this command to create a journal.

CRTJRNRCV: Use this command to create a journal receiver.

DLTJRN: Use this command to delete a journal.

DLTJRNRCV: Use this command to delete a journal receiver.

DSPJRN: This command displays or prints the journal entries that are in the journal receivers associated with the specified journal. This command has outfile support so you can list the journal entries to a database output file for further processing or analysis.

DSPJRNRCVA: Use this command to display the attributes of a journal receiver.

ENDJRNPF: This command ends journaling for the specified physical file.

RCVJRNE: This command allows a specified user program to continuously receive journal entries one at a time as they are written to the journal. The behavior is similar to an exit program.

RMVJRNCHG: Use this command to remove changes that have occurred to a database file from a specified point in time to some previous point in time (allowed only if before-images were recorded during the time).

RTVJRNE: Use this command to retrieve a journal entry and place it in CL program variables.

SNDJRNE: Use this command to write user-defined entries to a journal (i.e., journal receiver).

STRJRNPF: Use this command to start journaling for the physical file.

WRKJRN: This command displays a menu from which you can perform many journal-related functions, such as system-assisted recovery of journaled files.

WRKJRNA: This command displays the attributes of a journal and the associated receivers.

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