Answer Posted / venkat
The format of this keyword is:
UNIQUE[(*INCNULL | *EXCNULL)]The parameter is optional. When specified, it determines whether null key values cause duplicates. *INCNULL is the default and indicates to include null values when determining duplicates. *EXCNULL, when specified, indicates to exclude null values when determining duplicates.
When a logical file based on a physical file has the UNIQUE keyword, the physical file member or members cannot have duplicate key values.
When you specify the UNIQUE keyword for a physical or logical file, you must specify the MAINT(*IMMED) parameter value on the Create Physical File (CRTPF) or Create Logical File (CRTLF) command that creates the file. This means that the access path is maintained immediately when changes are made.
If you do not specify the UNIQUE keyword, records with duplicate key values are sequenced in the order you specify. If you specify the FIFO keyword, they are sequenced in first-in first-out order. If you specify the LIFO keyword, they are sequenced in last-in first-out order. If you specify the FCFO keyword, they are sequenced in first-changed first-out order. If you do not specify FIFO, LIFO or FCFO, the order in which the records are sequenced is not guaranteed.
You cannot specify the UNIQUE keyword with the FIFO, LIFO, FCFO, or REFACCPTH keywords.
Example
The following example shows how to specify the UNIQUE keyword for a logical file.
|...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8
00010A*
00020A* SAMPLE LOGICAL FILE (CUSMSTL)
00030A*
00040A UNIQUE
00050A R CUSREC PFILE(CUSMSTP)
00060A TEXT('Logical File Master Record')
00070A CUST
00080A NAME
00090A ADDR
00100A K CUST
| Is This Answer Correct ? | 1 Yes | 0 No |
Post New Answer View All Answers
We have job which is running as batch. It takes atleast 06 hours to complete tht job. But I wanna do tht job with in 3 hours?
Explain mdt?
if there is a module object , how to find the program object for this module object.Assume the module object name and program object name is not same.
Interviewer asked me write down DDS for load all subfile .can anybody write dds
How Chain operation copies the record's data to the input buffer for the program?
can I touch the array during treatments?
What is ment by record level identifier?
What are the types of identifiers?
how does the rpg element work?
How to create a login screen using a command instead of display file.... intention is to get a password field on a command..... how do you achieve this...
what is a rpg?
write an RPG program to calculate the marks of 5 students (A,B, C, D, E)in 3 different subjects (eng, math, sci) an display on the screen
How can we know running job is batch or interactive?
Assume 2 users are using the same file and first user updates some record in the file. Will the 2nd user will be able to see the updated record or not?
how can I tell when to replace the array?