|AS400 Interview Questions and Answers Part15
Q1: What is LPAR?
LPAR stands for Logical Partition, it provides to run multiple OS on the same IBM i system units which never interface with each other.
Q2: What is Data Queue in AS400?
Data queue is a queue that stores the free format messages. It is the type of system object that one can create to which a program or procedure can send data and from which another program or procedure can receive data. For further information please refer to Data Queue in AS400.
Q3: What is file information data structure(INFDS) in AS400?
INFDS Data structure is associated with a file that is declared in the F-SPEC in RPG program. It also gives file exceptions or errors and feedback information from the file. For further information please refer to File information data structures (INFDS) in RPG AS400.
Q4: What is program status data structure(PSDS) in AS400?
PSDS Data structure gives the program error subsection information to us like divide by 0, invalid date or time, etc. Program Status Data Structure in RPG AS400.
Q5: What is the Access path in AS400?
A file contains the Access path that describes how the records are retrieved from the file. For more information please refer to Access Path and Types of Access Paths in AS400.
Q6: What are the record format field mapping options in CPYF?
Copy File (CPYF) command copies all or part of a file from the database. We need to specify this option when we are copying physical files or logical files to the physical file or copying data between data file and source file. They have several options:
Q7: What are the difference between access path and dynamic select?
A file contains the Access path that describes how the records are retrieved from the file whereas Dynamic select is applied at the run time when the program executes and selects the dynamic records from the file.
Access path exists before the program gets called however that's not the case with Dynamic select
Q8: Why do we face this error "All records formats for externally described file <FILE1> ignored or dropped due to error, file ignored"?
When the filename and record format name are the same then this error occurs. So, to resolve this issue we need to rename the record format name using RENAME keyword with the file being defined in the F-SPECS of the RPG program.
Q9: What are the difference between ITER and DO statements?
DO is a looping statement while ITER is a branching statement. ITER used inside the loop will skip the current iteration of the loop and transfer the control to the ENDDO statement so that the next possible iteration could be executed.