7. PARAMETERS › 7.3 Unit Level Parameters › 7.3.1 DB2 Processing Options (DB2OPS) › 7.3.1.2 Internal Step RESTART Statements
7.3.1.2 Internal Step RESTART Statements
RESTART YES/NO
--------------
This statement is optional. Specify this to activate
internal step restart for this product's DAILY and/or INCRccc
database update job steps:
RESTART YES
If you do not specify or enable the RESTART parameter, then
this option defaults to the following and internal step
restart is disabled:
RESTART NO
*************************************************************
* *
* Note: Changing the RESTART parameter (either from NO *
* to YES or from YES to NO) requires regeneration *
* of the DAILY operational job by executing *
* prefix.MICS.CNTL(JCLGEND) or by specifying *
* DAILY in prefix.MICS.PARMS(JCLGENU) and *
* executing prefix.MICS.CNTL(JCLGENU). *
* *
* If incremental update is active for this product, *
* you must also regenerate the INCRccc job. *
* *
*************************************************************
Internal step restart can significantly reduce time and
resource usage to recover from daily and/or incremental
update processing failures. CA MICS uses a
checkpoint/restart technique.
o When internal step restart is activated, the database
update job step "checkpoints" (or saves) intermediate
results (work file contents) and the operational
environment at the end of each processing phase.
o Then, if required, the database update step can resume
execution at the beginning of the processing phase in
which the failure occurred.
o Restart is accomplished by restoring the operational
environment from the last checkpoint, bypassing completed
processing phases, and resuming execution using
intermediate results (work files) from the last
checkpoint.
Note: When you activate internal step restart (RESTART YES),
the following optional restart parameters are enabled.
These parameters have no effect if restart is disabled
(RESTART NO). For more details, see the individual
parameter descriptions later in this section.
o RESTARTCKPT data_set_allocation_parameters
o RESTARTWORK data_set_allocation_parameters
o DYNAMWAIT minutes
Processing Phases:
------------------
This product employs three database update processing phases,
followed by the two common roll-up phases.
Phase Description
------------- ------------------------------------------
FORMAT Read raw input data, convert to SAS
format, and output to intermediate work
files.
DELTA Perform required delta processing on the
DDY, DSB, DSD, and DSY files.
DBUPDATE Sort intermediate work file contents,
eliminate duplicate input data, merge data
across optional multiple work files,
enhance data content, and create the new
DETAIL cycle.
DYSUM Summarize DETAIL data to create new DAYS
cycles and to update current week-to-date
and month-to-date cycles.
DYAGE Cutover new database cycles to production
and "age" existing cycles.
RESTART Considerations
----------------------
o Overhead
Enabling internal step restart adds some overhead to the
database update job step -- the cost of taking
checkpoints and managing saved materials. Since this
overhead is relatively constant and independent of input
data volume, you may find that costs outweigh potential
savings when input data volume is low, for example in a
test unit. For high volume, production units, internal
step restart support overhead should be a minor portion
of total resource usage.
o Cataloged Work Files
When internal step restart is enabled, the SAS work data
set, internal step restart control data set, and multiple
work file data sets are allocated and cataloged with
permanent dataset names so they will be retained for use
in restart if the step abends. These data sets are
deleted when the step completes successfully.
Prior to enabling internal step restart support, these
data sets were probably allocated on system "scratch"
space with a temporary, system assigned data set names.
If your installation standards do not allow "permanent"
data sets on DASD volumes used for temporary work space,
you may need to use the WORK, RESTARTCKPT, and
RESTARTWORK parameters to direct the internal step
restart data sets to a generic unit or storage class that
allows cataloged data sets.
o Dynamic Allocation
When internal step restart is active, dynamic allocation
is employed for the work data sets. If your installation
restricts dynamic allocation of large, cataloged data
sets, you may need to use the WORK, RESTARTCKPT, and
RESTARTWORK parameters to direct work data set allocation
to a generic unit or storage class where dynamic
allocation is allowed.
o Data Set Names
The SAS work data set, internal step restart control data
set, and multiple work file data sets are allocated and
cataloged according to the standard CA MICS unit database
data set name conventions. The default DDNAME and data
set names are:
o SAS work data set,
//cccXWORK DD DSN=prefix.MICS.cccXWORK,.....
o Internal step restart control data set,
//cccXCKPT DD DSN=prefix.MICS.cccXCKPT,.....
o Multiple work file data sets,
//WORKnn DD DSN=prefix.MICS.cccWRKnn,.....
Since these data sets conform to the same data set name
conventions as your existing CA MICS data sets, there
should be few, if any, data set name related allocation
issues. However, it is possible to override the data set
names if required. Please contact CA MICS Product
Support for assistance if you must alter data set names.
RESTARTCKPT
-----------
This statement is optional. Specify the following to
override default data set allocation parameters for the
internal step restart checkpoint data set:
RESTARTCKPT data_set_allocation_parameters
Note: RESTARTCKPT is ignored when you specify RESTART NO.
The internal step restart checkpoint data set (or cccXCKPT
data set) contains processing status, control, and SAS
environmental information for internal step restart
processing checkpoints. This includes a copy of the SAS WORK
format and macro catalogs, current macro variable values, and
a description of work files that may be needed to restart
DAYnnn processing.
By default, the cccXCKPT data set is allocated according to
the values you specified for the WORKUNIT and WORKSPACE
parameters in prefix.MICS.PARMS(JCLDEF). Specify RESTARTCKPT
to override this default, either to alter the space
allocation or to use System Managed Storage (SMS) parameters
to control data set placement and characteristics.
Note: If you allocate insufficient space for the cccXCKPT
data set, DAYnnn processing will fail and can only be
restarted from the beginning.
Note: You can override the RESTARTCKPT data set allocation
parameters at execution-time using the //PARMOVRD facility.
For more information about execution-time override of dynamic
data set allocation parameters, see the PIOM, section 2.3.6.
Specify data set allocation parameters, separated by blanks,
according to SAS LIBNAME statement syntax. If you need
multiple lines, repeat the RESTARTCKPT keyword on the
continuation line.
RESTARTCKPT accepts the engine/host options documented in the
SAS Companion for the z/OS Environment, including STORCLAS,
UNIT, SPACE, BLKSIZE, DATACLAS, MGMTCLAS, and VOLSER.
Important! DO NOT SPECIFY THE DISP PARAMETER.
Example 1:
RESTARTCKPT STORCLAS=MICSTEMP SPACE=(xxxx,(pp,ss),,,ROUND)
where:
STORCLAS - specifies a storage class for a new data set.
The name can have up to eight characters.
SPACE - specifies how much disk space to provide for
a new data set being allocated, where:
xxxx is TRK, CYL, or blklen
pp is the primary allocation
ss is the secondary allocation
and ROUND specifies that the allocated space be
"rounded" to a cylinder boundary when the unit
specified was a block length. ROUND is ignored
with the TRK or CYL options.
Example 2 (multiple lines):
RESTARTCKPT STORCLAS=MICSTEMP UNIT=SYSDA
RESTARTCKPT SPACE=(xxxx,(pp,ss),,,ROUND)
where:
STORCLAS - specifies a storage class for a new data set.
The name can have up to eight characters.
UNIT - specifies the generic unit for a new data set.
The name can have up to eight characters.
SPACE - specifies how much disk space to provide for
a new data set being allocated.
RESTARTWORK
-----------
This statement is optional. Specify the following to
override default data set allocation parameters for the
internal step restart WORK data set:
RESTARTWORK data_set_allocation_parameters
Note: RESTARTWORK is ignored when you specify RESTART NO.
The internal step restart WORK data set (or cccXWORK data
set) contains the intermediate work files that are not
enabled to multiple work file support, including those files
you may have specified on the optional NOMULT statement.
By default, the cccXWORK data set is allocated according to
the values you specified for the WORKUNIT and WORKSPACE
parameters in prefix.MICS.PARMS(JCLDEF). Specify RESTARTWORK
to override this default, either to alter the space
allocation or to use System Managed Storage (SMS) parameters
to control data set placement and characteristics.
Note: If you allocate insufficient space for the cccXWORK
data set, DAYnnn processing will fail and can only be
restarted from the beginning.
Note: You can override the RESTARTWORK data set allocation
parameters at execution-time using the //PARMOVRD facility.
For more information about execution-time override of dynamic
data set allocation parameters, see the PIOM, section 2.3.6.
Specify data set allocation parameters, separated by blanks,
according to SAS LIBNAME statement syntax. If you need
multiple lines, repeat the RESTARTWORK keyword on the
continuation line.
RESTARTWORK accepts the engine/host options documented in
"SAS Companion for the z/OS Environment", including STORCLAS,
UNIT, SPACE, BLKSIZE, DATACLAS, MGMTCLAS, and VOLSER.
Important! DO NOT SPECIFY THE DISP PARAMETER.
Example 1:
RESTARTWORK STORCLAS=MICSTEMP SPACE=(xxxx,(pp,ss),,,ROUND)
where:
STORCLAS - specifies a storage class for a new data set.
The name can have up to eight characters.
SPACE - specifies how much disk space to provide for
a new data set being allocated, where:
xxxx is TRK, CYL, or blklen
pp is the primary allocation
ss is the secondary allocation
and ROUND specifies that the allocated space be
"rounded" to a cylinder boundary when the unit
specified was a block length. ROUND is ignored
with the TRK or CYL options.
Example 2 (multiple lines):
RESTARTWORK STORCLAS=MICSTEMP UNIT=SYSDA
RESTARTWORK SPACE=(xxxx,(pp,ss),,,ROUND)
where:
STORCLAS - specifies a storage class for a new data set.
The name can have up to eight characters.
UNIT - specifies the generic unit for a new data set.
The name can have up to 8 characters.
SPACE - specifies how much disk space to provide for
a new data set being allocated.
The following section discusses enabling this option:
1 - Enable Internal Step Restart
