Assume my file has 100 records and I want to see only first 10 records. Is this possible through lf?
Answer / sagar sudhakar wagh
Yes it is possible through LF. We can use SELECT/OMIT keyword to filter the record of physical file according to our need.
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What are different ways to pass data between programs and which one is the efficient way?
IBM AS/400 VERSION 1.1 Frequently asked Questions in AS/400 1. Define a shared access path? To share the open data path by various programs in a same job. 2. What is the difference between array and a multiple occurrence data structure? The values stored in array don’t vary. In the other hand, we can store the Different values in same variables at various stages. 3. What is *INZSR used for? 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. 4. How can you execute a command from within an RPG program without calling a CLP program? By calling QCMDEXC application program interface we can execute a CL command with in an RPG program. 5. What is the purpose of the "N" in the following calculation specification? 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. 6. Which of the following operations does NOT zero the field FLDA defined as 4,0? 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. 7. How can you check for a records existence without causing and I/O (CHAIN/READ)? 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. 8. Define what a data area is along with a brief example of what it may be used for? 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. 9. Define what a data queue is along with a brief example of what it may be used for? 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. 10. What is the purpose of the following? I 'CLOSED' C STAT01 I 'OPEN' C STAT02 It is a type of initializing the variables in I- spec. and these are further used in C-spec. 11. What is the difference between UDATE and the system date? UDATE supports two-digit year. The format is *MDY (MMDDYY). *DATE (system date) supports four digit year. The format is *MDYY (MMDDYYYY). 12. List some of the commonly used commands for debugging STRDBG(for batch jobs), STRISDB. 13. Define the RCVF command? RCVF command used to receive the records either from the data base file or device file. 14. Define the purpose of the %SST function? To extract the information from the specified string. 15. Define the purpose of the *CAT function? To concatenate the two strings into a one string. 16. Define the purpose of the *BCAT function? To concatenate the two strings by placing a single blank in a resultant. 17. Describe the difference between the DOWxx and DOUxx operations? 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. 18. Define the purpose of the LEAVE operation? If you specify LEAVE, the control transfers to the statement below the ENDDO. 19. Define the purpose of the ITER operation? If you specify the ITER, the groups of statements are allowed to execute repeatedly. 20. List the steps/commands necessary to accomplish the following: a. Copy data from the file ORDHDR into file ORDHIST b. The file ORDHIST may or may not exist c. If the file ORDHDR does exist, it may or may not contain data d. The file ORDHIST may or may not contain data, if the file does contain data the old data should be erased Commands: a. CPYF FILE(ORDHDR) TOFILE(ORDHIST) b. CPYF FILE (ORDHDR) TOFILE (ORDHIST) CRTFILE (*YES) c. CPYF FILE (ORDHDR) TOFILE (ORDHIST) *ADD d. CPYF FILE (ORDHDR) TOFILE (ORDHIST) *REPLACE 21. What is the purpose of the following? FORDHDR1 IF E K DISK ORDHDRF KRENAMEORDHDRF1 In order to rename the record format of a data base file in a program, we can use the above steps. Purpose of renaming is: If the record format name is similar in two files and if both are used in a same program, the program will not compile. Hence we have to rename either of the file. 22. What is the purpose of the following C/COPY QRPGSRC,ORDERR During the compilation the source code of ORDERR copy book is copied into the existing program. Where as /COPY is compiler directive statement. 23. What is the purpose of the following FORDHDR1 CF E WORKSTN $2SFN SFILE FMT2 The above line indicates that, $2SFN is a relative record number and FMT2 is name of the subfile record format. 24. What is the purpose of the following I UDS I 1 60ORDER# I 7 90LINE# The purpose is to define the variables in I-Spec and these are further used in C-spec. Where as ‘U’ indicates data area data structure? The above code is used to update the data area value through the program. The letter "U" indicates that the defined data structure is a data area data structure. 25. What is the purpose of the following? A CSRLOC (F1ROW F1COL) Using this record level keyword, you can specify cursor location on an output operation to the record format you are defining. The program sends output after setting the cursor location. 26. What is the difference between SFLCLR and SFLINZ? SFLCLR : It clears the subfile. SFLINZ : First it clears the subfile and initiliazing the numeric variables with zeros and alphanumeric variables with characters. 27. Define the purpose/use for SFLRNA? Using this, we can make specified subfile record format inactive. 28. Define what the operation will do, the purpose of the result field and the purpose of *IN66? HI LO EQ C CALL 'CVTDAT' DTPRM 66 The above statement causes, call the program and pass the parameter. 29. Define each of the following operation codes a. READ To read the records sequentially. b. READE To read the equal key records c. READP To read the previous records d. READC To read the records from the workstation file (Subfile). e. REDEP To read the equal key previous records. 30. Define the purpose of the following code (If you know, how would this be written in RPG ILE) HI LO EQ C *IN66 DOUEQ *OFF C KEY1 CHAIN FILEA 90 66 C 66 CALL PGM1 PRM C ENDDO Whenever the indicator *IN66 becomes *OFF, the control transfers after ENDDO statement. Otherwise, it reads the records from the data base file based on indicator specified on HI position. If the specified indicator on LO position becomes *OFF, then only CALL statement will execute. 31. How do you set the keywords SFLSIZ and SFLPAG if you want the subfile to dynamically expand? SFLSIZ > SFLPAG. 32. When would you use or not use this approach? It is the most desirable method in building a real time applications. We can use at all the times. 33. How can you detect and handle a record lock situation? 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. 34. How can you detect overflow for a print program that prints multiple lines per cycle? 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. 35. 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? 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 36. How would you join 3 separate fields, a first name, middle initial and last name together as 1 field with proper spacing? You can describe in either RPG and/or RPG ILE (Integrated Language Environment) MOVE 'Dr. ' FNAME 3 MOVE 'JOHN' MNAME 4 MOVE 'WATSON' LNAME 6 FNAME CAT MNAME: 1 VAR1 8 VAR1 CAT LNAME:1 VAR2 15 DSPLY VAR2 MOVE *ON *INLR 37. When PGMA calls PGMB for the first time PGMB executes the *INZSR. PGMB uses the RETRN operation to return to PGMA. When PGMA call PGMB the second time is the *INZSR executed? If you specify RETRN in called program, the *INZSR will not execute again. 38. Show 2 ways to convert a date from YYMMDD to MMDDYY (MULT operation not acceptable) 1) CVTDAT DATE() RTNVAR( ) FROMFMT( ) TOFMT( ) Source code is required to convert from one date format to another date format. The source code in CLP is given below: PGM DCL VAR(&VAR1) LENGTH(6) TYPE(*CHAR) VALUE('YYMMDD') DCL VAR(&RCVD) LENGTH(6) TYPE(*CHAR) DCL VAR(&VAR2) LENGTH(4) TYPE(*CHAR) DCL VAR(&VAR3) LENGTH(2) TYPE(*CHAR) CHGVAR VAR(&VAR2) VALUE(%SST(&VAR1 3 4)) CHGVAR VAR(&VAR3) VALUE(%SST(&VAR1 1 2)) CHGVAR VAR(&RCVD) VALUE(&VAR2 *CAT &VAR3) SNDMSG MSG(&RCVD) TOUSR(*USRPRF) ENDPGM 39. Determine the value of the result field a. Cost = $110. 00 b. Tax = 20% c. MarkUp= 05% d. Sale = 10% C Eval TotalCost = ((Cost * MarkUp) * Tax)) - Sale = 1. 0$ 40. Define the purpose of Factor 1 the Operation Code and *IN15 in following code HI LO EQ C *YMD Test(D) yymmddDate 15 If the factor 1 value matches with factor2 value, the indicator specified in EQ comes *ON. 41. Describe the function of SETLL operation in RPG language? 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. 42. Describe the function of SETGT operation in RPG language? 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. 43. What is the purpose of Level Check parameter in a Physical file? Specifies whether the level identifiers of the record formats in the physical file are checked when the file is opened by the program. 44. Define a Job Queue? Job queues are queues of batch jobs waiting to be processed. 45. Define a Output Queue? Output queues are queues of jobs waiting to be printed. 46. What is the function of CPYSPLF command? It copies the spooled file to the data base file. 47. What is the function of CPYF command? To copy the data from the one file to another. 48. What is the function of CRTDUPOBJ command? To create the replica from the original object. 49. Define Subsystem? Subsystem is nothing but it provides specialized environment to complete the execution of jobs. 50. What are different types of Substems? QBATCH, QINTER, QSPL, QCMN, QCTL, QBASE. 51. Define a Batch Job? * 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. 52. Describe about Query/400? 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. 53. What is the CLP command to access a Query/400? WRKQRY 54. Purpose of Overrides? 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. 55. Define Data Structure? 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. 56. What is the purpose of Data structure? * 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. 57. List and explain the different type of data structures? * Data area data structure When the data area is defined in an RPG/400 program as a data area data structure, its data is implicitly retrieved for processing and written back at the end of the program. In the data area data structure, letter "U" must be entered to define the data structure as a data area data structure. * File information data structure A file information data structure provides exception/error information that may be occurred when processing a file during program execution. This type of data structure contains pre defined sub fields that identify * The name of the file for which the error occurred * The record processed when the error occurred * The operation being processed when the error occurred * The status code number * The RPG/400 routine in which the error occurred. Exception errors may be controlled by testing for an error code in the *STATUS field which is included in a file information data structure. Specifically, keywords including *FILE, *RECORD, *OPCODE, *STATUS, *ROUTINE provide the previously named information. * Program status data structure Program status data structure however identity exception/errors that are generated in the program by RPG/400 operations and not by a file. Note that any code greater than 00099 is flagged as an exception/error. Four keywords - *STATUS, *ROUTINE, *PROGRAM, *PARMS are supported by a program status data structure. 58. What is the purpose of DYNSLT keyword? 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. 59. What is the difference between access path and Dynamic select? 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. 60. Why would you prefer OPNQRYF than logical file? The main difference is : Logical file creates permanent object on the system. OPNQRYF creates temporary access path. 61. When would you prefer logical file than OPNQRYF? 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. 62. What the purpose of the keywords FIFO, LIFO, FCFO? These keywords are used at file level. The purpose of each one is described below: 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. 63. What is the difference between regular logical file and join logical file? Regular logical file contains more than one record format. Record format name in regular logical file should be same based on the physical file. Join logical file contains only one record format. Record format name in join logical file should be different. Through logical file we can made changes in physical file. Through join logical file we can't made changes in physical file. 64. Distinguish between logical file and physical file? Physical file contains only one record format. Logical file contains more than one record format. Physical file contains actual data. Logical file doesn't contains data but it provides view from the physical file. 65. What is field reference file? Field reference file is a file, which contains field definitions and descriptions, and it doesn't have member. Physical contains data derived by the field reference file. 66. What is the necessary keyword used in a physical file to refer field definitions from the field reference file? REF which is a file level keyword is necessary to define at file level in a physical file. The syntax is as follows: REF(library name/name of the field reference file) 67. What is the purpose of reorganizing the physical file i. e. , RGZPFM? Even if you delete the records in a physical file through the program, still the space used by the deleted records not used by the other purpose. Hence using RGZPFM command we can compress the deleted records space. 68. What is the purpose of CHGPF (Change physical file) command? CHGPF command is used to change the attributes of a physical file. Attributes like * Maximum number of members * Member size * Level check enforced * Open data path is shared 69. What is purpose of declarative statement DEFN? Depends on the factor 1 value it will do two things: * If the factor1is *LIKE then DEFN opcode defines the new field based on the attributes old field. * If the factor 1 is *NAMVAR then DEFN opcodes defines the field as a data area. 70. What is the purpose of SFLNXTCHG keyword in a subfile? Which is a subfile record format keyword. If you perform read on the subfile, the internal indicator MDT (modified data tag) is automatically set off by the system. If you again perform read on the same records, records won't be read. Because internal indicator MDT would be off. Hence you should be explicitly set on the MDT by SFLNXTCHG keyword. 71. What is the difference between Array and Table? Array: Array is stored any where in the body of the input records. Table: Table is stored at the begining of the input records. Array: We can access all the elements in array by specifying the array name. Table: Only one table element can be accessed at a time. Array: Array can be searched randomly. Table: Table can be searched consecutively. 72. What are the different types of access paths maintained on the file? Immediate: All the access paths (open and close) associated with a file will be updated whenever changes made to a file. Rebuild- only open access paths will update whenever changes made to the file. Rebuild takes place whenever remaining access paths will be open. Delay : Rebuild will not takes place. 73. How can you identify End of file in CLP program? With the help of MONMSG MSGID(CPF0864) we can identify end of file in clp program. 74. What is the difference between production library and test library ? In debug mode, the files exists in production library not allowed to update. In the other hand, the files exists in test library allowed to update. 75. What is message subfile? Message subfile is special file contains multiple messages taken from program message queue and placed in message sub file for display on the screen. 76. What are necessary keywords to code message subfile? SFLMSGRCD, SFLMSGKEY, SFLPGMQ 77. What is the difference between SETON LR and RETRN? 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. 78. When will you use OPEN and CLOSE opcodes in RPG program? If you specify the letter "U" at columns 73 - 74 in a file description specification indicating that user control on a file. Hence we have to explicitly open and close the file in a program. 79. What is difference between fully procedural file and primary file? In primary file the records will be read and processed from begining to end. This order is not changed. In fully procedural file the records will be read and processed in any order. The logic flow is controlled by the opcodes in RPG program. 80. What is the difference between externally described file and program described file? The field definitions and descriptions are defined out side of the program in a externally described file. The field definitions and descriptions are defined in side the program in a program described file. 81. How many primary files allowed in a program? Only one primary file is allowed in program. 82. How many secondary files allowed in a program? More than one secondary files are allowed in a program. 83. What is the purpose of RTVMBRD command? In order to access the information related to member, we can RTVMBRD command. 84. Define an Interactive Job? * A user requests a job. * Job is created and job name, job attributes are assigned. * Job is placed on a job queue. * The sub system QINTER takes the job from the job queue and starts processing. * The output generated by the interactive job is placed on the output queue * The spool sub system QSPL prints the output. 85. How can you check the existence of object in a system? With the help of CHKOBJ clp command, we can find existence of object on the system. The usage of command in clp is as follows: CHKOBJ OBJ(JBA001DT) OBJTYPE(*DTAARA) MONMSG MSGID(CPF9801) EXEC(DO) CRTDTAARA DTAARA(QGPL/JBA001DT) TYPE(*CHAR) LEN(6) + VALUE('010196') TEXT('The last day that had job acct.+ data extracted') ENDDO RTVDTAARA DTAARA(JBA001DT *ALL) RTNVAR (&FROMDATE) The execution of above steps is listed below: steps 1: First it checks the data area object on the system. 2: If the data area object not found, the MONMSG command executes with the help of message identifier, next we can dynamically create the data area. 3. If the data area object found, control transfers to statement below ENDDO. It is always good CLP programming approach to check the object before you rename, delete the objects on the system. 86. What is the purpose of FRCDTA (Force Data) keyword? Use this record-level keyword to immediately display a record format, without waiting for the next input or output/input operation. 87. What is the purpose of SFLFOLD and SFLDROP keywords? SFLFOLD: To fold the second line of multiple line subfile. SFLDROP: To drop the second line of multiple line subfile. 88. What is the function of DSPATR (display attributes) keyword? Use this field level keyword in display file to specify one or more display attributes for the field you are defining. You can specify the DSPATR keyword more than once for the same field, and you can specify more than one attribute for the same keyword. The following are valid attributes: For All Fields Display Attribute Meaning BL Blinking field HI High Intensity RI Reverse Image CS Column separator ND Non Display PC Position cursor UL Underline For Input-Capable Fields Only PR Protect contents of field from input keying MDT Set modified data tag when displayed OID Operator identification SP Select by light pen 89. What is the purpose of PUTOVR (Put with explicit override) keyword? 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. 90. What is the purpose of OVRDTA (Override Data) keyword? Use this field level keyword with PUTOVR keyword to override the existing the data contents of a field already on the display. 91. What is the maximum number of record formats in DSPF? 1024 (One thousand and twenty four) 92. What is the maximum number of fields under a record format of physical file? 8000 (eight thousand) 93. What is the maximum number of parameters allowed in RPG? 255 (Two hundred and fifty five) 94. What is the maximum number of parameters allowed in CLP? 43 (Forty three) 95. What is the maximum number of subroutines allowed in RPG? 254 (Two hundred and fifty four) 96. What is the maximum number of files allowed in RPG? 50 (Fifty including eight printer file) 97. What is maximum number of Arrays allowed in RPG? 250 (Two hundred and Fifty ) 98. Where can you specify an indicator in LOKUP operation? In 'EQ' position. 99. What is a Member? It is a subset of data records of a physical file. 100. What is a Physical file? Physical file nothing but a table contains a only one record format in which we can describe the field definitions and descriptions. 101. What is a Logical file? It is nothing but a logical view provided by the physical file. 102. What is Join Logical file? Join logical file joins more than one file. The maximum of number of files allowed to join is 32 (thirty two). 103. What are the necessary keywords for the Join Logical file? JDFTVAL, JFILE, JOIN, JFLD, JREF. 104. What is a Non-join logical file? It only provides logical view based on the physical file. This is also called as regular logical file. 105. What is the necessary keyword for Non-join logical file? PFILE (which is record level keyword) 106. How many levels are there in a Physical file? Four levels. They are File level, Record level, Field level, Key field level. 107. What is the use of UNIQUE keyword and what level it is defined? It will avoid to enter duplicate key values. We have to define it in a file level. 108. At what level S,O are defined and what they will do? 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. 109. What is the difference between Packed decimal and Zoned decimal? Packed decimal : One digit occupies 1 byte. Zoned decimal : One digit occupies 2 bytes. 110. What is default data type (if you define decimals '0') in Physical file? Packed decimal 111. What is default data type for the fields(sub fields) defined in data structures in RPG? Zoned decimal 112. What is the use of JDFTVAL in join logical file? If you specify JDFTVAL at file level, even the primary file record does not match with secondary file record, the join takes place. 113. Is it possible to create a physical file without DDS? Yes. With the help of CRTPF we can achieve this. But we have to give record length. 114. What is a Keyed physical file? Defining a field as a key in physical file. Hence we can access records through the key field. 115. What is a composite key? Defining more than one key as a key field in physical file. 116. What is arrival sequence? The records will be accessed the way in which records are added to physical file. 117. What is the maximum number of key fields allowed defining in a physical file? 120 118. What is acronym of RPG? Report Program Generator 119. What is the native language of AS/400? RPG/400 120. Why RPG/400 is famous? * Easy to code and analyze. * Supports externally described files. 121. How many specifications are there in RPG/400? What are they? There are seven specifications are exits in RPG/400. They are listed below: * Header Specification * File Description specification * Extension specification * Line counter specification * Input specification * Calculation specification * Output specification 122. When do you use F-spec. continuation line ? * 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. 123. What are the various types of device files? Display files, printer files, discket files, tape files etc. , 124. When do you explicitly open files and close files in an RPG program? If you specify the letter ' U ' at column 73-74, you need to be open and close files explicitly in a RPG program. 125. How do you know that records are locked? By using a command WRKOBJLCK. 126. What is the purpose of Indicators in RPG? In order to control the logic flow, we can use indicators in RPG. 127. How do you read data area in an RPG program? With the help of 'IN' opcode, we can access the data area record in to the program. 128. What are the different types of Data Areas? 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. 129. What are various techniques to pass parameters from one program to another? PLIST, CALL, TFRCTL 130. Which single RPG opcode performs both SETLL and READE? CHAIN 131. What is term CUA , SAA? Common User Access System Application Architecture 132. Why is AS/400 called Object Oriented Machine? Everything on the AS/400 System that can be stored and retrieved is contained in the object. 133. What is the version of OS/400 that we have? V4R2 (Version 4. 0 Release 2. 0) 134. What is DDM ? 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. 135. What is an Object? An object is any thing that exists in and occupies space in storage and on which operation can be performed. 136. How are the objects stored on AS/400? 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. 137. What is a Library in AS/400? A library in AS/400 is an object that serve(acts) as a repository for other objects. 138. Name few IBM supplied libraries? QGPL, QTEMP, QSYS, QUSRTOOL, QCBL, QRPG 139. What is library list ? A list that indicates libraries used for the process and the order in which it has to be searched System identifies it in *LIBL. 140. How many libraries can be there in library list ? Total 40 (15 system and 25 application) 141. What is Folder? 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. 142. What is Spool file, Why is it required? A file that holds output data to be processed, such as information waiting to be printed. 143. What is Job, What are the attributes of a Job? A Job is a basic unit of work on AS/400. The attributes are: Job Number Unique system generated sequential number Job Name Any user defined name (Max 10 char) User Name Who initiated the job. 144. What is Job description? A Job description defines an environment in which a batch job or an interactive job to be executed. 145. What is the difference between Interactive & Batch Job? Interactive Job: A Job started for a person who signon to a workstation. Batch Job : A predefined group of processing actions submitted to the system to be performed. 146. What is Group Job? A Group Job is attached to one workstation and a user. There should be an initial group job and it can be branched to many other group jobs. The group jobs can have different library lists and different output, message queues. Group Job is useful in enhancing the programmers productivity. It is as though logging into the same user-id many times. 147. What are the two main attributes, which govern the execution of a job? Run time priority and Time slice 148. What is Sub-System? Sub-Systems are specific user defined partitions of the CPU where various jobs may be executed. One subsystem can have more than one active job at a time. 149. What is a Device file? A device file contains the description of how data is to be presented to a program from a device or vice versa. Device file can be Printer, Disk, Tape and Remote system. 150. What is an ICF file? A device file that allows a program on the system to communicate with program in other system. 151. What is a message file? It is a file which contains the messages of an application. For example all RPG/400 messages are stored in a file, all COBOL/400 messages are stored in a file. 152. What is a job log? A record of request submitted to system be a job. The message related to the requests, and action performed by the system on the log. The system program maintains it. 153. What is the purpose of OPNQRYF (Open Query File)? OPNQRYF is used to select certain records of the database file based on the QRYSLT (Query select ) condition. 154. How to create files dynamically without DDS? Through OPNQRYF 155. What command must be executed before executing OPNQRYF command? OVRDBF (Override Data base file) 156. What is Data Area? Data area is an object used to hold data for access by any job running on the system. A data area can be locked to a single user, thus preventing other users from processing at the same time. 157. What are the types of data areas? User defined Data Area, Local Data Area (LDA), Group Data Area (GDA), Program Initialization Parameter (PIP) Data Area. 158. What is LDA? LDA is created by the system for each job in the system, including auto-start jobs, jobs started on the system by a reader, and subsystem monitor jobs. 159. What is the type, length of a LDA? *CHAR, 1024 bytes 160. What is GDA? The system creates a GDA when an interactive job becomes group jobs. Only one GDA can exists for group. 161. How to create a user defined (general) data area? Using CRTDTAARA command 162. What are the different ways to input data into data area? CHGDTAARA (using CL) Using OUT opcode in RPG 163. How to retrieve data from data area? Using RTVDTAARA command in CL. Using IN opcode in RPG 164. What are the valid user defined data area types? CHAR, NUMERIC and LOGICAL 165. How can a data area be locked after being updated? Using OUT *LOCK 166. What is the use of Data Queues? Data queue is a type of system object that you can create. Data Queues are used in Program to program communication. 167. How to create a data queues? Using CRTDTAQ command. 168. What are the valid data types in Data Queue? Char, Numeric, and Logical 169. What are the two types of read performed on data queues? Read with lock, and read without lock. 170. How do you use DEBUG utility? STRDBG program-name UPDPROD(*YES) 171. What is an authorization list? A lists of two or more user Ids & their authorities for system resources. The system identifies it an object type *AUTL 172. How do you grant authority? Using GRTOBJAUT command 173. What are the types of object authorities? *USE, *CHANGE, *ADD, *DLT, *READ, *UPD, *ALL, *EXCLUDE, *OBJEXIST, *OBJMGT, *OBJOPR 174. How do you put jobs in batch mode? SBMJOB 175. What is the use of OVRDBF ? You can use the Override with Database file (OVRDBF) command to replace the database file named in a CL program or to change certain parameters of the existing database file. 176. What is the use of OVRPRTF ? Override with Printer file (OVRPRTF) command is used to override certain parameters of the printer files used in the program or to replace the printer file. 177. How to change file attributes such as size, file wait time, record wait time etc. , permanently? Using CHGPF command 178. What is the use purpose of CRTCMD? To create user defined command. 179. What is class of service ? A set of link and node characteristics associated with a session. 180. How to see active jobs of the system. Using WRKACTJOB command 181. How do you detect unused spool storage? Using Reclaim Spool Storage. 182. What are the functions of Remote Job Entry (RJE) ? Allows user of AS/400 system to submit jobs and receive jobs from a host system. 183. What is the function of RJE Conversion Utility? It converts compressed data written to an AS/400 database file to decompressed data written to another AS/400 database, diskette, or device file. 184. What process the command SBMRJEJOB does? Sends RJE input stream to host system 185. What is journaling & Commitment Control? Journaling is a function which records the changes in a file in a journal. These record images are used to recover the changes in the file should the system ends abnormally. Commitment control is a function that allows you to define and process a number of changes to database files as a single unit (transaction). 186. What is the purpose of STRCMTCTL command? Starts commitment control for files that are being journalled. 187. What are the system objects required for journalling? Journal receiver, journal and PFs to be journalled. 188. What are the different definition levels in Data Description Specifications? File level, Record level, Field level, Join level, Keyfield level, Select/Omit level. 189. What the difference between Source Physical File and Physical File? A Source Physical File contains the source for the various objects created this file has specific structure. A Physical File contains data, and the record format can be different for different physical files. 190. What is an access path? The order in which the database fields are organized for processing in the program. 191. What are all the different types of access path? Arrival sequence access path. Keyed sequence access path. 192. What is the default value for the number of increment for the physical file? Three 193. When does the DFT keyword in PF be used? To specify the default value it a field. 194. What is Multi-format logical file? Logical which uses fields from two or more physical files. 195. What is the Select and Omit criteria in logical file? This is used to specify rules for the Selection/Omission of records from a Physical File. 196. Can fields be concatenated INa logical file level? Yes. by using CONCAT keyword 197. When would the ALL keyword be used? Use with Select or Omit, to select/omit records. 199. What are the different types of keywords in display files? File level, Record format level, Field level 200. What is the maximum number of records you can specify in a display file? 1024 201. How can a screen field that has changed since the last output operation be detected ? Attach the MDT (modified data tag) attribute to the field, to detect whether field has been changed as a result of user input. 202. What would be the effect on the field where reverse image, underline and highlight display attributes were active? The result is same as if you had specified ND. 203. What is the use of DSPATR(MDT) keyword? 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. 204. If DSPATR(PC) and CSRLOC were specified for a format, which keyword would have priority? CSRLOC gains priority. 205. Can error messages as a result of a COMP, RANGE or VALUES keyword be overridden? Yes, through CHKMSGID keyword. 206. What the purpose of OVRDTA, OVRATA keywords? 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. 207. How can a message from a message file appear as a constant on the screen? By using MSGCON (message constant) keyword. 208. In conjunction with what other keyword must OVRDTA and OVRATA be used? PUTOVR keyword must used. 209. What is the purpose of the INDARA keyword? This File-level keyword is used to remove option and response indicators from the buffer and places them in 99- byte separate indicator area. 210. Explain the purpose of KEEP and ASSUME keywords? 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. 211. Explain the use of DFTWRT display keyword? No records will be displayed until there is any I/O operation. 212. What is the purpose of FRCDTA keyword ? Immediately display a record format without waiting for the next I/O operation. 213. What keyword must be used with PROTECT keyword? OVERLAY 214. What is Subfile? Subfile is group of records of same record format and can be read from or write to the display in a single operation. 215. What are all the contents of subfile? Subfile Record Format, Subfile Control Record Format, Relative Record Number, Subfile Record Number, Associated Subfile Keywords. 216. What are the two record formats a subfile contain ? Subfile record forma (SFL), and subfile control record forma (SFLCTL). 217. What is SFLPAG and SFLSIZ ? 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 subfile. 218. What is the maximum number of subfiles that can be specified in a display file, 512 219. Maximum number of subfiles that can Defined in a RPG program for one display file is 24 220. Maximum number of subfiles that can be active for a single file is? 12 221. Can more than one subfile record be displayed on one line? Yes, by using SFLLIN keyword. 222. How do you specify the number of records to roll in a subfile? Use SFLROLVAL keyword in DDS along with number, which specifies the number of records to scroll at a time. 223. How will you display a particular page in subfile? Move a valid relative record number (RRN) in the field specified using SFLRCDNBR keyword in DDS. 224. How to pick up the changed records every time in a subfile after the first change made? Seton SFLNXTCHG keyword indicator and update the subfile record. 225. What is the use of SFLEND keyword? By specifying this keyword, the Bottom/More message could be displayed at end of screen. 226. How to toggle between single line and Multi - line display of a particular record in a subfile? Using SFLDROP keyword. 227. Explain the difference between defining Subfile and Message-subfile? Subfile record is defined by SFL keyword, where as Message subfile is defined by SFLMSG keyword. 228. What are the different types of variables available in CL? DEC, CHAR, LGL 229. How do you pass parameters in CL? Using PARM keyword. 230. What is difference between CAT, TCAT, BCAT? 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. 231. What are the different types of messages in CL? Immediate message, Break message, Program message, User message 232. How to trap errors in CL? By using Monitor Message Command (MONMSG) 233. What is the maximum length of a variable name in CL? Maximum 11 characters (including '&') 234. What are the limitations of CL (compare to RPG) ? 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. 235. What is the use of Header Specification in RPG/400? It identifies by H in column 6, provides informaion about generating and running programs. 236. When will DUMP and DEBUG opcodes be ignored? If blank is specified in position 15 of H specs. 237. Specify different indicators used in RPG? Overflow indicators Record Identifying Indicators Field Indicators Resulting Indicators Control Level Indicators 237. What are Control level indicators? 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. 238. What is the use of E specification in RPG? Extension Specs describes all record address files, arrays and tables. 239. What is the use of L specs in RPG? Line counter specification can be used to describe printer file to indicate the length of the form and number of lines per page. 240. In which specification the report layout can be defined? O Specification. 241. How many files can be defined in F specs? 50 242. How many printer files can be defined in F specs ? 8 243. Give three main purposes of File specification ? To define files, to describe the files, to assign the files to specified devices. 244. How do you specify page overflow indicator for printer files in RPG? Specify an indicator in position 33-34 of F specification. 245. What is a Primary File? It is used in RPG Program Cycle to automatically read records in a cycle. 246. Can a indexed file be accessed in arrival sequence in RPG program? Yes. 247. What is a Program Described file in RPG? The field name and length of the fields are defined with in the RPG program. 248. What is externally described file ? All information about the fields is specified in DDS and the RPG program can use them with in the program. 249. Can you specify a display file to be used in the following modes Input, Output, or Combined modes ? Yes. 250. What is match field indicator? 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. 251. What is the length of a variable in RPG? 6 Characters. 252. When is a TAG statement used in RPG? It is used as Label. 253. What opcode could be used to test an alphanumeric field for all numeric values? TESTN 254. What opcode will be used to test the zone of a character field? TESTZ 255. How to read database records without locking them? Put 'N' in position 53 of C specs. 256. What does CHECK opcode is used? The check operation verifies that each character in the base string (factor 2) is among the character indicated in the comparator string (factor 1). 257. What does 'SR' in columns 7-8 of C specs mean? Calculation operation is a part of RPG subroutine. 258. What is SCAN and XLATE? 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. 259. How do you use commitment control in RPG program ? 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). 260. How do you use exceptional write in C specs? Using EXCPT opcode. 261. What does the opcode FREE do? 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. 262. What does opcode POST do? Puts information in INFDS. 263. What is the maximum number of elements in an array? 9999 264. Can we define Multi-dimensional arrays in RPG? No. 265. What is XFOOT opcode? Adds all the elements in a numeric array, and places the sum in the result field. 266. How can we sort an array? By using SORTA opcode. 267. How can the user implicitly open and close the files in RPG program ? Enter UC in position 71-72 of F specs. Use OPEN and CLOSE opcodes in RPG program to open and close files. 268 How many parameters can be defined in a RPG program. ? 255 269. What is File Information Data Structure? File Information Data structure (INFDS) can be defined for each file to make file exception/error information available to the program. A file information data structure contains predefined subfields that identify: the name of the file for which the exception/error occurred. the record being processed when the exception/error occurred or the record that caused the exception/error. The last operation being processed when the exception/error occurred. The status code. The RPG routine in which the exception/error occurred. 270. What is Program Status Data Structure? A Program status DS can defined to make program exception/error information available to an RPG program. DS is defined as program status DS by an S in position 18 of the DS statement. *STATUS contains status code. *ROUTINE : contains name of routine in which the exception/error occurred *PARMS : contains the number parameters passed to this program from the calling program. 271. What is the maximum number of times Multiple Occurrences DS can occur in a program? 9999 272. What are all the compiler directive statements? /TITLE, /SPACE, /EJECT, /COPY 273. What is SAA? Systems Application Architecture (SAA) is a collection of selected software interfaces, conventions, and protocols that will provide a consistent framework across the System/370, AS/400 and PS/2. 274. During execution, an RPG/400 program automatically follows a sequence of operations for each record that is processed. The built-in program cycle includes the following logical steps. 1. reading input (READ) 2. processing calculations (PROCESS) 3. writing output (WRITE) ************************************************************ ****************** 275. What is the Function of PDM? Productivity tool for copying, deleting, scanning, changing & creating source files. 276. What is the function of SEU ? A utility for editing programming language source code. 277. What is the use of SDA ? Screen Design Aid is used to create display files interactively. 278. What is a library in AS/400 ? Library in AS/400 is an object that serves as a repository for other objects. 279. Name few IBM supplied libraries ? GPL, QTEMP, QUSRTOOL, QSYS, QRPG & QCBL. 280. What is a library list ? Library list that indicates libraries used for the process and the order in which it has to be searched. System identifies it in *LIBL. 281. How many libraries can be there in a library list ? Total 40 (15 system and 25 application). DDS - Data Description Specification. Source Physical File contains the source for the various objects created. This file has a specific structure. RPG, CLP, DSPF, PRTF, etc. A-spec UNIQUE, PFILE, REFFLD 282. What is the difference between Physical and Logical files ? Physical file contains data, where as Logical file serves as a access path to database. 283. What does the keyword UNIQUE mean ? Records with duplicate key values are not allowed. 284. What is FCFO, FIFO, LIFO in Database environment ? These are file level keywords which are used to access the records in the order FCFO : First Changed First Out FIFO : First In First Out LIFO : Last In Fist Out 285. How many record formats can you have in a Physical file and in a Logical file ? Physical file can contain only one record format, Logical file can contain more than one record format. 286. What is Multi-format logical file ? Logical which uses fields from two or more physical files. 287. What is keyword PFILE specifies ? PFILE is used define the Physical file being referenced. 288. What is a Join Logical File, Can it be used for Update ? Logical file that combines more than one physical file. Update is not possible through JLF. 289. Is it possible to join the same file to itself ? Yes. 290. What does SDA stands for ? Screen Design Aid. 291. What is the symbol used for defining a new field in SDA? '+'. 292. What is the symbol used for shifting fields in SDA? '<' , '>'. 293. What is the symbol used for copying & moving new field in SDA? Copying : '-' & '=='. Moving : '-' & '='. 294. What is the symbol used to get name & length of a field in SDA? '?' . *DATE, *TIME. 295. How can a screen field that has changed since the last output operation be detected ? Attach the MDT attribute to the field, to detect whether field has been changed as a result of user input. 296. What would be the effect on the field where reverse image, underline and highlight display attributes are active ? The result is same as if you had specified ND. 297. What is the purpose of OVRDTA and OVRATA keywords ? 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. 298. What keyword must be used with PROTECT keyword ? OVERLAY 299. What is RPG ? Report Program Generator. 300. What are the different types of specification available in RPG/400 ? Control Spec.( H ) File Spec.( F ) Extension Spec.( E ) Line counter Spec.( L ) Input Spec.( I ) Calculation Spec.( C ) Output Spec.( O ) 301. Is it necessary to define all formats ? Which are mandatory and which are Optional ? No, all are Optional. 302. What is the use of E specification in RPG ? Extension Specs describes all record address files, arrays and tables. 303. In which specification can a report layout be defined ? O Specification. 304. How many files can be defined in F specs ? A maximum of 50 files. 305. Can an indexed file be accessed in arrival seQuence in RPG program ? Yes. 306. In which specification Data Structures can be defined? I - Spec. 307. When is a TAG statement used in RPG ? It is used as a Label. 308. What are the different Opcodes available in RPG for Database access ? READ, CHAIN, WRITE, UPDAT, DELET, SETLL, SETGT, READE, READP, REDPE, OPEN, CLOSE, FORCE, NEXT, UNLCK. 309. How can database records be read without lock ? Put 'N' in position 53 of C specs. 310. What does CHECK opcode do ? The check operation verifies that each character in the base string (factor 2) is among the ` character indicated in the comparator string(factor 1). 311. In conjunction with which statements can ORxx and ANDxx conditions be used ? DOUxx, DOWxx, IFxx, and WHxx. 312. What does opcode POST do ? Puts information in INFDS. 313. Can you have multiple key lists for a single file ? Yes. 314. What are the different types of arrays available in RPG ? Pre-execution time array. Compile time array. Execution time array. 315. Can we define Multi-dimensional arrays in RPG ? No. 316. What is XFOOT opcode ? Adds all the elements in a numeric array, and places the sum in the result field. 317. During input operation which indicator position is seton if there is a record lock? LO indicator position is seton. 318. What is the difference between *LIKE and *NAMVAR ? *LIKE defines the variables as in database. *NAMVAR is used to define variables as data area. 319. Where will control be passed after the execution of the *PSSR subroutine if the factor2 of the ENDSR is blank ? Control will return to the next sequential instruction. 320. What is the maximum number of subfiles that can specified in a display file ? 512 The maximum number of subfiles that can defined in a RPG program for one display file is ___ . 24 321. The maximum number of subfiles that can be active for a single file is ____ . 12 322. What are the different opcodes used for file operation on a subfile in a RPG pgm? READ, READC, CHAIN,UPDAT and WRITE 323. How will you display a particular page in subfile ? Move a valid relative record number(RRN) in the field specified using SFLRCDNBR keyword in DDS. 324. Can a single screen format occupy a screen area above and below a subfile format ? Not possible. 325. What is SFLPAG and SFLSIZ ? 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. 326. How to pick up the changed records every time in a subfile after the first change made ? Seton SFLNXTCHG keyword indicator and update the subfile record. 327. How do you specify the number of records to roll in a subfile ? Use SFLROLVAL keyword in DDS along with the number, which specifies the number of records to scroll at a time. 328. What are the three line types in RLU ? Report line, Filler line & Sample line. 329. What is the function of RLU ? To design & prototype a report. 330. What are the three types of keywords associated with printer file ? File level, Record level & Field level. 331. How do you combine two record formats in RLU ? Using CLC. 19. 332. What are the different commands used in RLU ? 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. 333. What is the command used to invoke RLU ? STRRLU. 334. What are different record spacing keywords in RLU ?
Anybody know the difference of primary file and full procedural file
how can an indexed file be used as arrival sequence in RPG?
In case if I want to know whether a record exists in a file, which one do you prefer CHAIN or a SETLL and why ?
3 members in databasefile .how to read records from all the members??
can i use UPDDTA command in rpg program in which contains a file
How do you proceed in case your active AS400 session has got disconnected suddenly, how can you get back to your session ? Is it possible??
why subproc not run in dftactgrp?????/plz explain
If my rpg program has a date field, what extra care I have to take while compiling that rpg program? If the file is keyed and I have declared the file as well as key list properly in my program. Still am getting an error message like "chain/reade operation is not allowed" what may be the case?
how to check on which PF , the LF is dependant ?