Application engine Interview Questions

1. What is  application engine ?

                Application Engine programs are PeopleSoft's batch processing technology. They are developed in application designer and consist of blocks of PeopleCode and SQL. Application engine programs can also use application classes, Component Interfaces, XML publisher reports, and call SQRs and COBOLs through PeopleCode.

2. What is application library?

                Application library is a program that contains collection of callable sections.  We can’t define application library with standalone program.

3. What are the Different types of Application Engine?
                Standard: Standard entry-point program.
                Upgrade Only: Used by PeopleSoft Upgrade utilities only.
                Import Only: Used by PeopleSoft Import utilities only
                Daemon Only: Use for daemon type programs.
                Transform Only: Support for XSLT Transform programs.
4.What is the difference between the %select and %selectinit meta SQL functions?

                %select        : If any values have not selected then previous values will be there

                %selectinit   : If any value have not selected then previous value reinitiate to null.

 5.What are the different types of  temporary tables in application engine program?

                Dedicated - They have lock management. (continue)

                Undedicated- There is no lock management on these tables. (Abort)

6. what are the different types of variables in the Application Engine people code?
Local variable – These are available for the duration of the program in which they are declared.
Global / Component – These variables are available while the Application Engine program is running. They are saved at commits and checkpoints, So they can be used for restarts. Component variables are same as Global incase of the AE.
7. What are the Different ways pass data between the steps?
                State records – One row can be passed and can have many state records.
                Component/Global People code variables
                Temporary records – Multiple rows of data can be passed.
8. What is Prerequisite for the State record?
                i)Should be either Derived work record Or SQL Table.
                ii)Name of the record must end in AET

                iii)PROCESS_INSTANCE must be a key.
                iv)Any data types except character or numeric must not be required fields.
Note: - No People code fires on an Application Engine state record.
No Validation of translate values or Prompt tables are done.
9.What is the difference b/w %select, %bind?

                %Select—used for inserting

                %Bind----- used for retrieving.

10.How do you execute Application Engine through Push Button?
                a.CreateProcessRequest () , Schedule ()
                b.CallAppEngine.

11. What is the syntax for CallAppEngine?
CallAppEngine (applid [, state record]);
12. What are the 3 trace parameters you can pass to your psae.exe?
                - TRACE , - TOOLSTRACESQL , - TOOLSTRACEPC 
13. Which Trace option is the best place to start for general performance information?
- TRACE 384 – mostly used trace value.
14. What is the difference between a Trace value and Trace parameters?
A Trace parameter determines which type of trace is turned on.
A Trace parameter determines what type of data is recorded in your trace files (s).
15. What are the 3 common ways to pass a trace parameter and value to your program psae.exe?
Configuration manager, Process Definition, Command prompt.
16.What is the difference between the exit(0),exit(1) when we are using this function in AE?

Exit(1) causes immediate termination of  a PeopleCode program. We use this parameter to rollback database changes.

Exit(0) causes immediate termination of a PeopleCode program but it doesn’t make rollback in the database.

17. What is Set Processing? 
Set Processing uses SQL to process groups or sets of rows at one time rather than processing each row individually. With set processing, you only select those rows that meet the filtering criteria and then run the rule once again all the affected rows. (With row by row processing you following a repetitive loop that selects a row, determines if it meets a given criteria, if so, apply rule x to row Update row, commit.)

18. Advantages of Set Processing?
Improved Performance, Minimized SQL Overhead, Easy Maintenance, Leveraging the RDBMS

19. Why call section and SQL are mutually exclusive?

Both CallSection and SQL are used to perform DML operations, To avoid Locking we will use either SQL or CallSection.

20. What is the use of temporary records and state record in application engine ?

Temporary Tables: Used to store the immediate values during the processing of the AE.
Help in batch processing by creating multiple instances and there by facilitating parallel processing.
State Records: Used to pass on values between sections/steps/programs.

21.How can you integrate workflow with A.E?

A.E programs triggers business events indirectly, by passing their queries to CI. If the component has associated with workflow, A business process is  trigger when the CI saves the  page.

22.What are the PeopleCode events used for CallAppEngine function.

SavePreChange ,SavePostChange, WorkFlow , FieldChange.

23.What is the Order of Action Events?

Do When ,Do while , Do select  ,People Code  , SQL/Call Section, Log-Message, Do Until.

24.What are the prerequisites for Temporary Record ?

Process instance as  a key and  name should end with _TAO

25. What are different types Do Select ?

                Select/Fetch

                Reselect

                Restartable