Databases Reference
In-Depth Information
9.3.1 Considering “What” and “When”
In Figure 9-1, you saw the database application life cycle represented as four phases:
design, implementation, production, and retirement. Let's continue by revisiting that
life cycle and how these phases relate to administrator responsibilities.
The design phase of the life cycle includes database and application design.
The majority of the work falls on the data administrator to perform the data analy-
sis, prepare the database design, and design database objects (including those
needed for data access). The data administrator must also work with application
programmers to ensure they understand the database design and to develop data
access standards. Keep in mind that even though these activities are considered
part of data administration, some of the design activities are handed off to the
programming staff, especially when there are experienced database programmers.
Much of the work might also be done by an outside consultant.
With implementation, responsibilities begin to shift more toward database
administration with the requirements to create the physical database and database
objects, to deploy the database, and to perform baseline monitoring. However,
there is still a significant amount of work for the data administrators. Not only
are you deploying the database, you are also deploying the data. There are going
to be significant requirements for data entry, data migration from other sources,
or (as it is in most cases) both. It may also be necessary to revisit the design phase
to correct problems or performance issues discovered during implementation.
Most of the issues that arise during the production phase, those relating to
day-to-day use and to ongoing maintenance, are database administrator respon-
sibilities. Issues relating to maintaining and securing the database require ongo-
ing monitoring and management. However, there are still issues that might arise
that are traditionally considered data administration issues, such as issues relat-
ing to arbitrating data access, the acquisition and integration of new data, or
requirements to modify the database design as business needs change.
You might be tempted to think that retirement, with its requirements for
archiving and protecting historical data, fall entirely on database administration.
However, as one database application phases out, a new one typically phases in,
and often the existing data is the foundation on which the new database and
application are built. Determining what data needs to be migrated is a data
administration requirement. Of course, determining the actual methodology used
to migrate the data and performing the data migration more often than not puts
the responsibility right back on the database administrator.
9.3.2 Considering “When” and “How”
We need to think about how different activities are performed. There are some
key, and closely related, considerations here. One consideration is the specific
processes required to perform different administration tasks. Another consideration
