2. Planning for Installation and Use of CA MICS › 2.3 Installation Planning and Parameter Specification › 2.3.1 Database Complex Planning and Parameters › 2.3.1.4 Database Complex Definition › 2.3.1.4.1 Planning Multiple Database Units

2.3.1.4.1 Planning Multiple Database Units

The CA MICS Database may contain one or more database
units.  The number of database units and the components in
each is defined by the user when CA MICS is installed.  This
section discusses the basic considerations which will affect
the number of database units you should install.  An example
is also presented to illustrate the considerations.

The key to understanding most of the considerations given
below is to remember that each of the database units has its
own update jobs which are run independently of the update
jobs of the other database units.

The basic factors affecting the number of database units you
should create are as follows:

1. Installation Size.  Small installations or installations
   which only have a few components installed are more likely
   to have a single production database unit.

2. Component Data Source.  Components which use the same
   input data source should be kept in the same database
   unit.  The best example of this is the SMF,RMF,TSO, and
   CIC components which may all receive their input from the
   SMF tapes.

3. Input Data Availability.  Components which obtain input
   data from different data sources may be put in different
   database units to avoid the operational problems of
   getting the different data sources together at the same
   location and time for a database update.

4. Input volume.  Components which have high volumes of input
   data may be separated from others in order to break the
   total update time into several smaller jobs.

5. Flexibility and Reliability.  Having several database
   units increases the flexibility in performing update and
   other operations on the database.  In addition, if a
   problem is encountered in the database, only part of the
   database is affected.

6. Overhead.  There are some increases in overhead for each
   additional database unit.  These include library space
   for all of the prefix.MICS libraries, additional SAS
   overhead to repeat the SAS initialization and compilation
   for each update, and increased operational tasks of
   managing the execution of additional update job streams.

7. Testing Capability.  We recommend that every site install
   a test database unit.  The test unit will provide you with
   a controlled environment for developing CA MICS additions
   and modifications without endangering the integrity of
   your production databases.

An Example

To demonstrate some of the points above, consider the
following hypothetical example for a company with a large
data center and a smaller center located in a physically
separate site.  The two centers have the following
configurations:

Site A (Main Site):

     System        Workload

     A001          TSO, batch
     A002          TSO, batch, IMS
     A003          CMS
     A004          IMS
     A005          TSO, batch, CICS

    Components to be installed:

      SMF, RMF, TSO, CIC, IMS, SRL, and MTI field developed
      applications for integrating NSM Performance Trend data
      for distributed systems.

Site B (Small Site):

     System        Workload

     B001          TSO, batch

    Components to be installed:

      SMF, RMF, TSO, CIC, SRL


Notes:

1. System A001 is the primary TSO machine.

2. System A004 is a dedicated IMS machine processing
   5,000,000 transactions per day for a major IMS
   application.  All other IMS applications run on system
   A002 which processes 1,000,000 transactions per day.

3. CMF is used as the input source for CICS.

A total of seven database units is appropriate for site A,
and 1 database unit for site B.  The database units for
site A contain the following components:

unit 1 - SMF, RMF, TSO (which all use SMF tapes as input.)

unit 2 - CIC (separated because of data volume)

unit 3 - IMS (for system 4; separated because of data volume)

unit 4 - IMS (for system 2; all other IMS work)

unit 5 - SRL (separated because the input data source is
              different)

unit 6 - MTI Field Developed Applications

unit 7 - a test database to develop and test user
         modifications.

The CA MICS database for site B processes a much smaller
volume of input data, and so all components are located in
one database unit.  A test database unit might also be
installed at this site if user modifications are to be
developed here.  If software development and control is done
from the main site then the test database unit there would
suffice.