1. Database Structure › 1.2 Database Structure and Organization › 1.2.1 Online Data Structure › 1.2.1.5 Cycle (Database Level 4)

1.2.1.5 Cycle (Database Level 4)

The Cycle level is the fourth and lowest within the database
structure and is organized within File, Information Area, and
Timespan.  The Cycle level enables a File to be separated
into N number of mini-files related to the actual processing
cycles used in updating the Database.

This level is best explained through illustration.  Assume
that there is a requirement to retain fourteen days data for
the TSO System Activity File in the DAYS Timespan.  Keep in
mind that in the DAYS Timespan a Cycle would normally
contain the measurement data for a single day.

With the above requirement in mind, the user would define
the Database to hold 14 days of data for the TSO System
Activity File by specifying that 14 Cycles of the File should
be retained online.  In this manner, it is assumed that as
each day is processed another Cycle for this File is created,
until finally after 14 days the required data spanning 14
days is online.

Therefore, as in the case of the TSO System Activity File
that must be maintained for fourteen days, a means to age
Cycles is required.  This is accomplished by having the Cycle
occur within the File level once for each day it is to be
maintained.  Consequently, in this illustration, there will
be fourteen unique TSO System Activity File Cycles aged as 01
(the last day or cycle processed), 02 (the 2nd last cycle),
through 14 (the Cycle that was processed thirteen day's ago).

An aging procedure is used to manage the Cycles within a
File.  Prior to adding the newly created Cycle (today's data
for the DAYS Timespan, for instance), the highest defined
Cycle is deleted (14), and the remaining Cycles 01-13 are
'aged' to now become Cycles 02-14, so that the Cycle being
added, is always inserted as the 01 Cycle.

It is important to understand that a Cycle is defined to
contain data for a day, week, month, and year, for the DETAIL
and DAYS, WEEKS, MONTHS, and YEARS Timespans respectively.
This definition is based on the CA MICS Database update
processing one day's data each day, and running the weekly,
monthly, and yearly updates at their scheduled times.

In the Database design, each Cycle represents the SAS
data set that is to be processed.  By concatenating all of
the Cycles, the full TSO System Activity File (all 14 days)
may be processed.

Figure 1-7 illustrates the Database structure through
level 4:

                           DATABASE
                               |
             +--------+--------+---------+--------+
             |        |        |         |        |
Level 1:   DETAIL   DAYS     WEEKS    MONTHS   YEARS
                      |
                      |
                      |
        +-----+-------+---------+-------+-----+
Level 2:|     |       |         |       |     |  ...etc.
      ADMIN  TSO   HARDWARE  MVS SCP  BATCH  IMS
              |   UTILIZATION
              |
             +---+-------+----------+----------+
             |           |          |          |  ...etc.
Level 3:  TSO System  TSO User  TSO User    TSO User
          Activity    Activity   Command   Interactive
                        |        Counts     Usage
                        |
Level 4:                |
   +--+--+--+--+--+--+--+--+--+--+--+--+--+
   |  |  |  |  |  |  |  |  |  |  |  |  |  |
  01 02 03 04 05 06 07 08 09 10 11 12 13 14

Figure 1-7. Cycle Level Structure