6. Database Tailoring and Retrofitting Techniques › 6.2 Tailoring the Database › 6.2.1 Tailoring Data Elements › 6.2.1.2 Common Data Elements › 6.2.1.2.1 Changing Attributes of Common Data Elements
6.2.1.2.1 Changing Attributes of Common Data Elements
Changing the attributes of a common data element involves
making modifications to the CA MICS Component Generator (MCG)
TYPE group that includes the common data element. This will
be done in one of the following sharedprefix.MICS.GENLIB
members:
o Elements that are common to all CA MICS files are
defined in sharedprefix.MICS.GENLIB($DEGENIN).
o Elements that are common to the files in a single
CA MICS product are defined in the applicable cccGENIN
member, where ccc is a CA MICS product identifier.
Refer to the information in Section 4.2.4.4.1 of this guide
for information about the statements in the TYPE group.
The following example will be used in discussing the
considerations for changing common element attributes.
...
COMP NPA 050 32000 VBS NOACCT NPA Component
TYPE XR 3 . 3 . 3 .
NAME NPANRRLS Receiving Line Speed (line/link)
TYPE XR 3 . 3 . 3 .
NAME NPANRSLS Sending Line Speed (line/link)
TYPE XA 5 TIME11.2 6 TIME15.2 6 TIME15.2
NAME NPATMAOT Actual Observation Time
...
AREA NPA NPA Activity Information Area
...
Changing the description of a common data element changes
the element in all files in which it is referenced. Such
changes are:
- Changing the format or length specification of the
element.
- Changing the label attached to the data element.
- Changing the type code of the data element.
For example, the data element NPATMAOT could be changed
as follows:
New Type New Length and
Code Format for
(Common MONTHS and
Maximum) YEARS time-spans
| |
V V
... -- -----------
TYPE XM 5 TIME11.2 6 TIME15.2 8 TIME18.2
+-->ALIAS NPATIME
| NAME NPATMAOT Actual Measurement Time
| ... -----------------------
| New Label
|
+---hypothetical new data dictionary
member where all NPA time data
elements would be documented
(for example only; no such
convention exists or should).
***********
* CAUTION *
***********
Changes to common data elements affect all files in which
each changed data element appears. The following items must
be considered:
- Common data elements are often used as file sequence
elements for the files in which they appear. Even if
they are not in any file's key, they may be very
important by virtue of being used in many places or
being used in extended, user-generated report
processes. These data elements should not have their
attributes modified without the advice of the CA MICS
Product Support Group. Further considerations are
discussed in Section 6.2.2.3 of this guide, which
addresses the impact of changing a file's sequence in a
time-span.
- Section 6.2.1.1.3 of this guide presented
considerations for changing existing data element
definitions. The information presented there also
pertains to common elements.
- Changing the definition of a data element will not
necessarily be reflected immediately in time-spans
greater than DAYS. Accumulating data to the WEEKS,
MONTHS, and YEARS time-spans takes some time to
complete. Also, the accumulation of to-date data in
these time-spans may result in combining unlike data.
Changing data elements from accumulated to maximum or
minimum, for example, will always produce spurious
results in these time spans until a new interval is
begun in each time-span, and unlike data is no longer
combined in the archive files.
You should examine the need for retrofitting existing
data in such situations. If the need for a retrofit
exists, refer to Section 6.3 of this guide.
****************************
* Making the Modifications *
****************************
To change a common data element's attributes,
- Modify the MCG control statements explained above for
each common data element to be modified.
- Generate the component by running the cccCGEN job for
each affected product.
- The next daily update for any database unit in which
the product has been installed will reflect the change.
