JCL EXEC STEP

karthik1680 · New User Joined: 14 May 2005 Posts: 64 Location: chennai

IN BELOW JCL STATEMENT WHAT DOES DYNAMBR=20 MEAN?

//STEP01 EXEC PGM=IKJEFT01,DYNAMNBR=20

thanooz · New User Joined: 28 Jun 2005 Posts: 99

hi karthik,

Dynamic allocation allows a job to acquire resources as they are needed and release them immediately after use. The resources are a ddname-data set combination with its volumes and devices.
One reason to use dynamic allocation is that you may not know all of the device requirements for a job before execution. Another reason is that it allows the system to use resources more efficiently; that is, the system can acquire resources justbefore their use and release them immediately after use.
To tell the system the number of resources to be held in anticipation of reuse, code:
//stepname EXEC PGM=x,DYNAMNBR=n
The system uses the sum of this number and the number of DD statements in the
step to establish a control limit for tracking resources that it is holding in anticipation
of reuse.

This will help's you.

Thak's
thanooz.

karthik1680 · New User Joined: 14 May 2005 Posts: 64 Location: chennai

hi
thnks for u r answer, could u explain it detaily?

thanooz · New User Joined: 28 Jun 2005 Posts: 99

hi karthik,

Dynamic allocation allows a job to acquire resources as they are needed and release them immediately after use. The resources are a ddname-data set combination with its volumes and devices.
One reason to use dynamic allocation is that you may not know all of the device requirements for a job before execution. Another reason is that it allows the system to use resources more efficiently; that is, the system can acquire resources justbefore their use and release them immediately after use.
To tell the system the number of resources to be held in anticipation of reuse, code:
//stepname EXEC PGM=x,DYNAMNBR=n
The system uses the sum of this number and the number of DD statements in the
step to establish a control limit for tracking resources that it is holding in anticipation
of reuse.

The control limit is the sum of the number of DD statements coded and the
value coded in the DYNAMNBR parameter:
in u r case
no DD statements u decare + 20
If this control limit is reached and another dynamic allocation is requested, the request is not honored unless resources can be unallocated so that the control limit is not exceeded.

martin9 · Posted: Thu Mar 16, 2006 5:54 pm

hy karthik1680,

this is common jcl syntax,
please read the manual first, there is all described.

martin9