Distributed Files Example

In this comprehensive example, we create a distributed file called DISTCUST using a user defined partition algorithm and attaching five part files.

Create the distributed file stub. This is the file to which all part files will be attached:

jsh DEMO ~ -->CREATE-FILE DISTCUST TYPE=DISTRIB [ 417 ] File DISTCUST]D created , type = J4 [ 417 ] File DISTCUST created , type = DISTRIB

Define the partition algorithm. If the distributed file uses the default system partition method, this step would not be necessary unless you wanted to change the delimiter separating the part number from the record ID. For this example we will use the user-defined method by assigning the subroutine DistCustSub as the partition algorithm:

jsh DEMO ~ --> create-distrib –pUSER,DistCustSub DISTCUST

Create the five files to be attached as part files. If the files already exist then this step can be omitted:



jsh DEMO ~ -->CREATE-FILE DISTCUST.NORTH 1 101


[ 417 ] File DISTCUST.NORTH]D created , type = J4


[ 417 ] File DISTCUST.NORTH created , type = J4



jsh DEMO ~ -->CREATE-FILE DISTCUST.EAST 1 101


[ 417 ] File DISTCUST.EAST]D created , type = J4


[ 417 ] File DISTCUST.EAST created , type = J4



jsh DEMO ~ -->CREATE-FILE DISTCUST.WEST 1 101


[ 417 ] File DISTCUST.WEST]D created , type = J4


[ 417 ] File DISTCUST.WEST created , type = J4





jsh DEMO ~ -->CREATE-FILE DISTCUST.SOUTH 1 101


[ 417 ] File DISTCUST.SOUTH]D created , type = J4


[ 417 ] File DISTCUST.SOUTH created , type = J4

jsh DEMO ~ -->CREATE-FILE DISTCUST.ERRORS 1 41 [ 417 ] File DISTCUST.ERRORS]D created , type = J4 [ 417 ] File DISTCUST.ERRORS created , type = J4

Attach the five files to the distributed file:



jsh DEMO ~ -->create-distrib -a DISTCUST 1 DISTCUST.NORTH


Part file 'DISTCUST.NORTH', Part number 1 added



jsh DEMO ~ -->create-distrib -a DISTCUST 2 DISTCUST.EAST


Part file 'DISTCUST.EAST', Part number 2 added



jsh DEMO ~ -->create-distrib -a DISTCUST 3 DISTCUST.WEST


Part file 'DISTCUST.WEST', Part number 3 added



jsh DEMO ~ -->create-distrib -a DISTCUST 4 DISTCUST.SOUTH


Part file 'DISTCUST.SOUTH', Part number 4 added

jsh DEMO ~ -->create-distrib -a DISTCUST 99 DISTCUST.ERRORS Part file 'DISTCUST.ERRORS', Part number 99 added

Now, let’s list the part files we have just added.

jsh DEMO ~ -->LIST-DISTRIB DISTCUST -or- create-distrib -l DISTCUST Partitioning Algorithm is USER Subroutine 'DistCustSub' Part file 'DISTCUST.NORTH', part number 1 Part file 'DISTCUST.EAST', part number 2 Part file 'DISTCUST.WEST', part number 3 Part file 'DISTCUST.SOUTH', part number 4 Part file 'DISTCUST.ERRORS',part number 99

The distributed file system is now complete. At this point, the DistCustSub subroutine is called each time a record is written to or read from the DISTCUST file.

Let’s say, for example, that we find that the DISTCUST.ERRORS part file is no longer needed. The actions we must take to remove this file from the distributed file are:

Detach the part file from the distributed file:
        DELETE-DISTRIB DISTCUST 99
                    -or-
        create-distrib -d DISTCUST 99

Modify the user-defined partition subroutine DistCustSub by removing the lines which allocate records to part number 99. Recompile and catalog.

Optional: Delete the DISTCUST.ERRORS file.
        DELETE-FILE DISTCUST.ERRORS

Distributed Files