Database Reference
In-Depth Information
15. Portability
a. Operating systems
(1) Unix
(2) Microsoft Windows
(3) Linux
(4) Other
b. Import/export/linking ile support
(1) Other databases
(2) Other applications (for example, spreadsheets and
graphics)
c. Internet and intranet support
16. Cost
a. Cost of DBMS
b. Cost of any additional components
c. Cost of any additional hardware that is required
d. Cost of network version (if required)
e. Cost and types of support
17. Future Plans
a. What does the vendor plan for the future of the system?
b. What is the history of the vendor in terms of keeping the
system up to date?
c. When changes are made in the system, what is involved in
converting to the new version?
(1) How easy is the conversion?
(2) What will it cost?
18. Other Considerations (Fill in your own special requirements.)
a.
266
?
b.
?
c.
?
d.
?
FIGURE 8-8
DBMS evaluation checklist
(continued)
1. Data definition. What types of data does the DBMS support? Does it support nulls? What about
primary and foreign keys? The DBMS undoubtedly provides support for indexes, but can you
specify that an index is unique and then have the system enforce the uniqueness? Does the
DBMS support views?
2. Data restructuring. What type of database restructuring does the DBMS allow? How easily can
the DBA perform the restructuring? Will the system do most of the work, or will the DBA have
to create special programs for this purpose?
3. Nonprocedural languages. What types of nonprocedural language does the DBMS support? The
possibilities are SQL, QBE, natural language, and a DBMS built-in language. If the DBMS sup-
ports one of the standard languages, what
s the quality of its version? If the DBMS provides its
own language, how good is it? How does its functionality compare to that of SQL? How does the
DBMS achieve optimization of queries? The DBMS optimizes each query, or the user must do so
by the manner in which he or she states the query. If neither happens, no optimization occurs.
Most desirable, of course, is the first alternative.
4. Procedural languages. What types of procedural languages does the DBMS support? Are they
common languages, such as Java, C or C++, and COBOL? Is it a graphical user interface (GUI)
language? Does the DBMS provide its own language? In the latter case, how complete is the lan-
guage? Does it contain all the required types of statements and control structures? What facili-
ties does the language provide for accessing the database? Does the DBMS let you use a
nonprocedural language while you are using the procedural language?
5. Data dictionary. What kind of data dictionary does the DBMS provide? Is it a simple catalog?
Or can it contain more content, such as information about programs and the various data items
these programs access? How well is the data dictionary integrated with other components of the
system
'
for example, the nonprocedural language?
6. Concurrent update. Does the DBMS support concurrent update? What unit may be locked (field
value, row, page, table, or database)? Are exclusive locks the only ones permitted, or are shared
locks also allowed? (A shared lock permits other users to read the data; with an exclusive lock,
no other user may access the data in any way.) Does the DBMS resolve deadlock, or must pro-
grams resolve it?
7. Backup and recovery. What type of backup and recovery services does the DBMS provide?
Does the DBMS maintain a journal of changes in the database and use the journal during the
recovery process? If a transaction terminates abnormally, does the DBMS roll back its updates?
Can the DBMS perform an incremental backup of just the data that has changed?
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