Multiple LSR pools are supported in some environments. DFP2 pools are supported in some environments. DFP2 allows eight LSR pools (pools 0 through 7), and DFP3 allows 256 LSR pools (pools 1 through 255). DFP3 further subdivides each LSR pool into separate data and index sub-pools.
The SHAREPOOL control allows you to assign a specific LSR buffer pool to a particular OPEN request. You can group several different files into the same LSR pool, for example. You can specify which files share a pool by using the SHAREPOOL control.
The SHAREPOOL control has a single operand. The operand is the pool number that you wish to be associated with this OPEN request. The specified pool must be in the range {1,...,MAX} where MAX is the maximum pool number allowed in your environment.
Specify SHRPOOL=0 only if you want to remove a pool specific selection that results from a constraint merge, for example:
. . . .
. . . .
CLUSTER=A.B.C
SHRPOOL=3,
. . .
. . .
CLUSTER=D.E.F
SHRPOOL=3
. . . .
. . . .
PROGRAM=XYZ
DDNAME=LOG * Assume this DD points to Cluster A.B.C
SHRPOOL=0 * WILL NOT use SHRPOOL 3 - pool will be chosen
* by CA-Hyper-Buf
. . . .
. . . .
The example shows that clusters A.B.C and D.E.F normally share the same LSR pool (Pool 3), if both happen to be opened in the same job step. However, if PROGRAM XYZ OPENs CLUSTER A.B.C on DDNAME LOG, SHRPOOL 3 is not automatically assigned. In this case, the file is dynamically assigned an unused LSR pool. This can be any LSR pool that is not assigned to another file, including pool 3, if that pool is unassigned.
CA Hyper-Buf attempts to determine which pools are assigned for each address space at the time of the first OPEN for that address space. Any pools that do not appear to be used are eligible for assignment by the LSR control. CA Hyper-Buf assigns the highest available unassigned LSR pool. Each subsequent LSR OPEN uses a lower number pool. Pools that are explicitly assigned by SHAREPOOL are skipped in this selection process.
Note: Dynamically allocated data sets may not yet be allocated at the time of the first OPEN. Any files that are dynamically allocated after the first OPEN in an address space may be forced to use a pool other than the SHAREPOOL specified pool, if the SHAREPOOL specified pool is already allocated to another LSR file.
If all available LSR pools are already assigned, the LSR option is ignored, and the file is opened with NSR buffering.
|
Copyright © 2011 CA.
All rights reserved.
|
|