2. Planning for Installation and Use of CA MICS › 2.3 Installation Planning and Parameter Specification › 2.3.2 Database Unit Planning and Parameters › 2.3.2.6 Compression (COMPRESS)
2.3.2.6 Compression (COMPRESS)
About the SAS System Compression Feature
----------------------------------------
The SAS system gives you the option to create variable-length
or fixed-length observations in a SAS data set.
Variable-length observations differ from fixed-length
observations in that the former are usually smaller because
the blank spaces used to pad fixed-length observations are
removed.
You instruct SAS to create variable length observations by
specifying the COMPRESS= option. SAS data set compression
can be implemented for individual data sets or across the
entire SAS system by specifying COMPRESS= on either a DATA
statement (for the individual data set named on the DATA
statement) or an OPTIONS statement (for the entire system).
For more information on the COMPRESS= option, see the SAS
Institute documentation.
CA MICS Implementation of Compression
----------------------------------
The COMPRESS member in prefix.MICS.PARMS enables you to
define which database files will be compressed in this
database unit.
The COMPRESS parameter is generated into
sharedprefix.MICS.GENLIB(CMPRSDEF). Each database unit's
COPYLIBU job adjusts the unit's prefix.MICS.PARMS(COMPRESS)
for new products. Once the COMPRESS member FILE statement
exists, COPYLIBU will not update it.
For files that can be compressed, the COMPRESS parameter
member controls compression specifications for the database
unit. You can control, unit by unit, whether or not
compression is active, and if it is, to what extent
compression is active for each file in the unit.
There is one exception to using the COMPRESS member to
compress files. CA MICS Accounting and Chargeback journal
files must be compressed using the Journal File
Specifications panel (MWF;4;2;3;6). Refer to the CA MICS
Accounting and Chargeback User Guide for more information.
The format of the COMPRESS parameter member is:
DBCOMPRESS sw ALL/ccc ccc ...
IFCOMPRESS ON ccc ccc ... -or- OFF
FILE ccc iiifff x d w m y
FILE ccc iiifff x d w m y
FILE ...
Each statement is described below.
DBCOMPRESS Statement
--------------------
The DBCOMPRESS statement enables you to activate or
deactivate the compression facility.
The format of the DBCOMPRESS statement is
DBCOMPRESS sw (ALL / ccc ccc ...)
where
sw is a switch whose values are ON and OFF.
ALL indicates that the value of sw (the switch) applies to
all products in the unit. ALL is the default.
ccc is a three-character CA MICS product identifier.
+-----------+---------------+-------------------------------+
|When sw | And the next | |
|is ... | value is ... | Then compression ... |
|===========|===============|===============================|
|ON | ALL | takes place for all files in |
| | | the unit. |
+-----------+---------------+-------------------------------+
|ON | ccc | takes place for only those |
| | | files belonging to products |
| | | in the list. |
+-----------+---------------+-------------------------------+
|OFF | ALL | does not take place for any |
| | | file in the unit. |
+-----------+---------------+-------------------------------+
|OFF | ccc | takes place for all files |
| | | EXCEPT the files belonging to|
| | | the products in the list. |
| | | (OFF for that product but ON |
| | | for the rest of the products|
| | | in the unit.) |
+-----------+---------------+-------------------------------+
For example, the DBCOMPRESS statement
DBCOMPRESS OFF
indicates that compression will not occur for any of the
products in this unit, while the DBCOMPRESS statement
DBCOMPRESS OFF SMF
indicates that compression will occur for all files in the
unit EXCEPT for those belonging to the Batch and Operations
Analyzer (ccc=SMF).
If the unit contains only the Batch and Operations Analyzer,
the statement
DBCOMPRESS ON SMF
is equivalent to the statements
DBCOMPRESS ON
and
DBCOMPRESS ON ALL
IFCOMPRESS Statement
--------------------
The IFCOMPRESS statement enables you to activate or
deactivate compression for intermediate (work) files for
products in this unit that support intermediate file
compression.
The format of the IFCOMPRESS statement is
IFCOMPRESS ON ccc ccc ...
-or-
IFCOMPRESS OFF
IFCOMPRESS ON ccc means that intermediate files for the
product(s) listed will be compressed
IFCOMPRESS OFF means that intermediate files are not
compressed
For example, the IFCOMPRESS statement
IFCOMPRESS ON CIC
indicates that the CICS Analyzer's intermediate files, which
include the Loader Domain Global Stats (GLD) and Temporary
Storage Global Stats (GTS) files, would be compressed.
The IFCOMPRESS statement does not support the ON ALL
qualifier, nor does it provide an exclude capability like
that provided with the format "DBCOMPRESS OFF ccc".
FILE Statement
--------------
FILE statements are initially copied by the COPYLIBU job from
the COMPRESS statements in the cccGENIN member of the
sharedprefix.MICS.GENLIB data set. (Once FILE statements
exist in prefix.MICS.PARMS(COMPRESS), the COPYLIBU job will
not copy them.)
Only products that support compression have FILE statements
in prefix.MICS.PARMS(COMPRESS). You can edit FILE statements
in prefix.MICS.PARMS(COMPRESS), but you should not add or
delete statements. If you add or delete COMPRESS statements
in cccGENIN, run sharedprefix.MICS.CNTL(cccCGEN) and then
prefix.MICS.CNTL(COPYLIBU) for each unit that contains the
ccc product to update the COMPRESS parameter library member.
The format of the FILE statement is
FILE ccc iiifff x d w m y
where
ccc the three-character CA MICS product identifier
iii the three-character CA MICS information area identifier
fff the three-character CA MICS file identifier
x through y determine whether or not data in this file's
timespan can be compressed when the compression facility is
activated.
+---------+---------+-----------+---------------------------+
|When ... | Is ... | Then ... | Timespan data ... |
+=========+=========+===========+===========================+
|x | Y | DETAIL | can be compressed. |
+---------+---------+-----------+---------------------------+
|x | N | DETAIL | cannot be compressed. |
+---------+---------+-----------+---------------------------+
|d | Y | DAYS | can be compressed. |
+---------+---------+-----------+---------------------------+
|d | N | DAYS | cannot be compressed. |
+---------+---------+-----------+---------------------------+
|w | Y | WEEKS | can be compressed. |
+---------+---------+-----------+---------------------------+
|w | N | WEEKS | cannot be compressed. |
+---------+---------+-----------+---------------------------+
|m | Y | MONTHS | can be compressed. |
+---------+---------+-----------+---------------------------+
|m | N | MONTHS | cannot be compressed. |
+---------+---------+-----------+---------------------------+
|y | Y | YEARS | can be compressed. |
+---------+---------+-----------+---------------------------+
|y | N | YEARS | cannot be compressed. |
+---------+---------+-----------+---------------------------+
For example, the FILE statement
FILE SMF BATJOB Y Y Y Y Y
indicates that data in the DETAIL, DAYS, WEEKS, MONTHS, and
YEARS timespans of the Batch User Job Activity file will be
compressed when the compression facility is activated.
Chapter 6 of the System Modification Guide includes
information about changing compression specifications.
Chapter 4 of this guide describes the CA MICS Administrator
Utilities available to help you evaluate data compression
savings.
