6. Database Tailoring and Retrofitting Techniques › 6.2 Tailoring the Database › 6.2.2 Tailoring Database Files
6.2.2 Tailoring Database Files
The middle level of tailoring involves changing database
file definitions describing online storage. (Offline storage
is discussed in section 6.2.3.)
CA MICS database files can exist in any of the following
online timespans: DETAIL, DAYS, WEEKS, MONTHS, and YEARS.
You control the amount of data that is kept in each timespan
(the number of cycles retained online). You also control
whether or not the data is compressed.
For example, the NPANCP file might be defined as follows:
DETAIL DAYS WEEKS MONTHS YEARS
-------- -------- -------- -------- --------
NPANCP01 NPANCP01 NPANCP01 NPANCP01 does not
NPANCP02 NPANCP02 NPANCP02 exist
... ... ...
NPANCP10 NPANCP53 NPANCP06
Defining cycles and compression is done in two places.
The CA MICS Component Generator's FILE statement defines the
timespans in which the file exists. For the NPA component's
NPANCP file, sharedprefix.MICS.GENLIB(cccGENIN) might contain
the following statement:
FILE NCP 00 1 Y Y Y Y N N Y Y NCP Activity File
| | | | |
| | | | +- does not exist in YEARS
| | | +--- exists in MONTHS
| | +----- exists in WEEKS
| +------- exists in DAYS
+--------- exists in DETAIL
The number of cycles that CA MICS will age within a timespan
is specified in the DBMODEL member of the unit-level CA MICS
parameter library. (Optionally, a CYCLES statement can be
coded after the FILE statement in the GENLIB library to
perform the same function.) The number of cycles does not
override the file's active/inactive status as defined by the
FILE statement. (If the file is not active but cycle
retention is greater than zero, the cycles are NOT retained.)
The ability to compress a file's data in a timespan is
specified in the COMPRESS member of the unit-level parameter
library. If you code a COMPRESS statement in the GENLIB
library, the COMPRESS parameter member will be created by
first COPYLIBU job executed after the COMPRESS statement is
added.
For the NPANCP file, the cycle definitions in
prefix.MICS.PARMS(DBMODEL) contain a FILE statement for the
NPANCP file that states the number of cycles to be aged in
each timespan:
FILE NPANCP 01 10 53 06 00 000 053 024
| | | | |
| | | | +- does not exist in YEARS
| | | +---- 6 cycles in MONTHS
| | +------- 53 cycles in WEEKS
| +---------- 10 cycles in DAYS
+------------- 1 cycle in DETAIL
To tailor the amount of space used by an online database,
you can:
o tailor the file cycle definitions in
prefix.MICS.PARMS(DBMODEL) or the CYCLES statement in
sharedprefix.MICS.GENLIB(NPAGENIN) to adjust the amount
of data retained
o tailor the file's data compression status using the
definitions in prefix.MICS.PARMS(COMPRESS) and on
NPAGENIN's COMPRESS statement in
sharedprefix.MICS.GENLIB
To carry a week's worth of DETAIL data instead of only one
day, change the FILE statement in DBMODEL to:
FILE NPANCP 07 10 53 06 00 000 053 024
--
|
+-- changed parameter
Because the NPANCP file is inactive in the YEARS timespan
(the FILE statement in sharedprefix.MICS.GENLIB(NPAGENIN) has
N coded for the YEARS timespan definition), the YEARS
timespan cycle definition on the NPANCP file's FILE
statement in prefix.MICS.PARMS(DBMODEL) must be 00. You
cannot activate the file in the YEARS timespan by changing
the cycle definition to a number greater than zero.
Likewise, the WEEKS timespan cannot be deactivated by
changing the cycle definition from 53 to 00. CYCLEGEN
execution errors will occur in either case.
To compress the NPANCP file's online data, first ensure that
the COMPRESS statement in sharedprefix.MICS.GENLIB member
NPAGENIN looks like the following:
COMPRESS Y Y Y Y Y
Then ensure that the prefix.MICS.PARMS(COMPRESS) member for
the unit in which the NPA component is installed contains, at
a minimum, the following:
DBCOMPRESS ON NPA
IFCOMPRESS ...
FILE NPA NPANCP Y Y Y Y Y