Definitions: Batch Mode - Disabling the forward recovery process.
Online Mode - Enabling the forward recovery process.
Cyclic Rename - Reversing the names of 2 files by the use of an interim
file name. For example: FILE.A to FILE.B and FILE.B
to FILE.A by first renaming FILE.A to FILE.X, then
renaming FILE.B to FILE.A, and finally renaming
FILE.X to FILE.B.
BPAM - Basic Partitioned Access Method. A PDS.
QSAM - Queued Sequential Access Method. A 'flat' file.
VSAM - Virtual Storage Access Method.
Physical Reorg - The process of creating a QSAM copy of a VSAM
cluster, Delete/Define of the VSAM cluster, reproing
the QSAM backup copy into the newly defined cluster,
and building any required alternate indices.
Logical Reorg - The process of reversing the roles of the production and
shadow VSAM files by applying a 'cyclic rename' to
each corresponding component of the VSAM cluster.
Trigger - A mechanism used to initiate an event.
In order to provide PM availability to the hospital staff with a minimum of downtime and
maintain efficient VSAM files, we have implemented automatic reorganization of the PM
VSAM data sets. The physical reorg is initiated when the CA/CI splits of the shadow
version of a PM VSAM data set exceed a preset trigger level. When the trigger level is
exceeded, the forward recovery system is quiesced (put in batch mode), the appropriate
shadow file is copied to a backup QSAM disk file, the shadow is deleted and defined, the
backup is copied back to the shadow cluster. Any alternate indices are then built. The
final step in the physical reorg is setting the logical reorg trigger by changing the control
in the appropriate member of the BPAM file 'NPPM3.PROD.D.PMCNTROL' to 'REORG'. Once all
of the PM VSAM files have been physically reorged, the forward recoveries are put back
into online mode and forward recovery process is initiated. During the midnight
downtime window, the PM production VSAM files are logically reorged by doing a cyclic
rename swapping the production files with their corresponding shadow files. The process
is initiated when the appropriate control trigger member contains 'REORG'. Once the
logical reorg is triggered, the appropriate PM VSAM production and shadow files are
tested to be certain that exclusive control will be obtained, the cyclic rename is
then completed, and the appropriate control trigger is set to 'NOREORG'.
The physical reorgs are run daily at 19:00 hours, which is a time when forward recoveries
are rarely running and also ensures that there is adequate time for the forward recoveries
to get caught up after the reorgs. The physical reorgs are initiated by job PPMV$SRO
which verifies that the shadows are available for reorg and puts the forward recoveries
into batch mode. PPMV$SRO (start reorgs) is the trigger for the PPMV$ROx (x = A thru H)
jobs which do the physical reorgs and set the trigger for the logical reorgs. Once
all of the physical reorgs are complete, job PPMV$TRO (terminate reorgs) is triggered
which puts the forward recoveries in online mode and submits the job PPMV$SUB which
starts the forward recovery system if any journal files are ready to be applied. If
exclusive control can not be obtained by PPMV$SRO, none of the dependent jobs are run,
consequently the physical reorgs will not be run until the next weekday.
The logical reorgs are run during the PM downtime window. The jobs are PPM3$IDx
(x = A thru H). Each of the logical reorgs consists of a step to ensure that exclusive
control can be obtained before the cyclic rename is attempted, renames are processed,
and the trigger member is set to 'NOREORG'. If exclusive control can not be obtained,
nothing happens and the trigger will remain set for the next midnight downtime period.
The logical reorgs can actually take over a minute to execute since several VTOCs
need to be changed as well as the system catalog. At the current time, we allocate
the PM VSAM files on 5 direct access storage devices.
Acronym Physical Reorg Logical Reorg File Description
ACT PPMV$ROA PPM3$IDA Activity File
APM PPMV$ROB PPM3$IDB Active Patient Master
CPI PPMV$ROD PPM3$IDD Corporate Person Index
CPP PPMV$ROE PPM3$IDE Corporate Person Pointer
HIX PPMV$ROH PPM3$IDH History Index
HPI PPMV$ROF PPM3$IDF Hospital Patient Index
NOT PPMV$ROC PPM3$IDC Note file
PEI PPMV$ROC PPM3$IDC Professional/Employer/Ins
RAB PPMV$ROC PPM3$IDC Room and Bed File
RAF PPMV$ROC PPM3$IDC PEI Extra Address File
SEG PPMV$ROG PPM3$IDG Segment File