can any one pls tell me some differences between a LF and
command OPNQRYF?
Answers were Sorted based on User's Feedback
Answer / vaiv20
LF creates a new object in the system while that is not the
case for OPNQRYF.
LF creates a permanent data access path to the physical
file that will be updated as and when and add,update and
delete operation is performed on file Whereas OPNQRYF
creates a temporary access data path that is shared by high
level pgm for further processing of recs in file.
| Is This Answer Correct ? | 30 Yes | 0 No |
Answer / senthilkumaran
The main difference is : Logical file creates permanent
object on the system. OPNQRYF creates temporary access
path.
| Is This Answer Correct ? | 16 Yes | 0 No |
Answer / amit
I agree with Vaiv20. Just want to add that OPNQRYF is used
with keyword Share(*Yes) and that's what makes the ODP
avaiable to high level pgms.
Also the usage of OPNQRYF is for adhoc jobs that are
executed once in a while whereas LF is used in case where
the ODP is going to be used pretty regularly. So LF object
would be prefered when the usage is going to be regular
where as OPNQRYF would be good where the job is going to be
once in a while.
LF would make the job faster compared to OPNQRYF though ti
depends on what kind of maintenance option you use for LF.
| Is This Answer Correct ? | 9 Yes | 0 No |
I want to change the attribute of field or want to add new field in existing PF but condition is format level identifier should not change, is it possible?
How many libraries can be there in a library list?
What is the difference between access path and open data path?
I have physical file with 100 records,there is no any duplicate records in this pf.based on this pf one logical file I have used.but this lf is viewing only 80 records only of that pf?what is the reason for this?
wirte a simple program for read file in cl
WHAT IS THE DIFFERENCE BETWEEN 'COLHDG' AND 'ALIAS'?
can any one tell me what is meant by PSSR? Kindly elaborate it...
In a CL Program after executing a SQL SP how to receive a Output value from the SP. Just to make it clear I am sending 2 input and 1 output parameter to the SQL Stored Procedure. Now while receiving it output parm it is failing.
1. How can I create a LF using crtlf command based on a particular member in a multimember PF? Where I have to specify the member name? 2. How to differentiate between the types of join from a Join logical file DDS. Is it possible to have different types of Join Logical files? 3.Any performance difference between Opnqrf and Embedded SQL? When I should prefer Opnqryf and when SQL? 4. I know access path is the path chosen by the program to retrieve data. It can be of keyed access path or arrival sequence. *IMMED- *IMMED description says access path is updated each time record is added or deleted from a member. - What is updating here? *REBLD - The access path is completely rebuilt each time a file member is opened. The access path is maintained until the member is closed, then the access path is deleted. - I am not able to understand this completely. Could anyone explain these more clearly? 5.What is the purpose of using activation group. I know it is a resource allocator, but other than this any other benefits of using an activation group?
Q.1 how to implement the commitment control. 2.how to control commitment control from external program.
When u create a PF and did not fill up Maint parameter, then by default which access path will the system take & why
can we concate fileds in physical file? If yes how can we do?