Databases Reference
In-Depth Information
YOU TRY IT
Planning a Centralized Environment
You have a heterogeneous network environment with
data stored on local PCs and on a mainframe com-
puter. The network links to the mainframe through a
gateway computer. You want to consolidate the data
on a centralized SQL database server. The transition
will be accomplished in phases, first consolidating the
PC data and then including the mainframe data.
The database server will support specialized cus-
tom database applications. The applications are being
developed in-house by staff programmers. You provide
assistance to the programmers as necessary. Most ac-
cess to the database server will be limited to access via
the database applications, but a small number of
clients will have direct access to the server.
At the same time, you are designing a separate data-
base that will support an online research and reference
application. Most of the tables needed for the application
will rarely need updating. Access to this server will be lim-
ited to a.NET Web application running on a Web server.
Your database server does not support locating ex-
ternal data sources unless they are explicitly identified.
directly support any one clinic. Instead, each clinic will
have its own local database server. Each office will
maintain its own separate staff, equipment, and inven-
tory records. Every clinic must have full access to all pa-
tient and treatment records. There are also a full set of
medical references online.
The primary concerns are accuracy, consistency,
security, and how quickly patient and treatment infor-
mation can be retrieved at the local clinics. All clients
need access to the medical references, but speed of
access to this information is less critical. Update la-
tency must be kept to a minimum. All communciation
between locations and all patient records are en-
crypted.
Treatment information is related to each patient and
includes information about any staff involved with the
treatment, medications given during the visit to the pa-
tient, and prescriptions written for the patient. The clin-
ics do not fill prescriptions, but do sometimes give out
samples they have received from drug representatives.
These are noted on the treatment record, but not
tracked in any detail.
You want to minimize storage requirements, but
must meet the performance expectations for data re-
trieval.
1.
Describe the requirements for supporting data
access during the intial deployment phases.
2.
You need to select the hardware platform
needed to support the SQL databases. The
databases will be hosted on different DBMS
products. Discuss the considerations for con-
solidating the data requirements on a single
computer. Justify your answers.
1.
Describe the data requirements at each clinic.
Include which tables, if any, would need to be
partitioned. Identify data, if any, that would be
stored on the consolidated data server only.
2.
Describe the replication requirements needed to
perform an initial load of the remote databases
and to mainiain data integrity and consistency.
Planning a Distributed Environment
You are designing and deploying a distributed data
environment that will support for-profit medical clinics.
You have completed the initial data design and the data
load on a database server that consolidates the records
for all of the clinics. The consolidated server does not
3.
Identify situations that would call for distributed
transactions. Be as specific as possible. Include
the steps necessary to execute a distributed
transaction using a two-phase commit process,
including the specific steps involved.
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