Database Modeling & Design Fourth Edition- P3 doc
Database Modeling & Design Fourth Edition- P3 doc
... available to
help design the most efficient databases. This book is devoted to the
logical design methodologies and tools most popular for relational
databases today. Physical design methodologies ... Tools for Logical Database Design 187
9.1 Introduction to the CASE Tools 188
9.2 Key Capabilities to Watch For 191
9.3 The Basics 192
9.4 Generating a Database from a Design 196
9....
Database Modeling & Design Fourth Edition- P6 docx
... concepts
that can be applied to the conceptual data modeling phase of the
database life cycle. In Section 2.1, we will look at the simple level of ER
modeling described in the original work by Chen ... all occurrences of that entity depend on an associated
(strong) entity for their existence in the database. For example, in Figure
2.1, the weak entity Employee-job-history is related to...
Database Modeling & Design Fourth Edition- P8 doc
... models with
different end user views was severely limited until it could be extended
to include database abstraction concepts such as generalization. The gen-
eralization relationship specifies ... three entities attached to a single relation-
ship diamond, and the connectivity of each entity is designated as either
“one” or “many.” An entity in a ternary relationship is considered to be
“o...
Database Modeling & Design Fourth Edition- P21 docx
... resulting table. The two
key attributes are taken from the same domain but are given different
names to designate their unique use. The one-to-many relationship
requires a foreign key in the resulting
Database Modeling & Design Fourth Edition- P24 doc
... diagram or
by taking the composite of all attributes as the default key. Note that the
primary key designation implies that the attribute is not null or unique.
It is important to note, however, ... keys of the associated entities as its composite primary key; the
components of that key are also designated as foreign keys in SQL. A ter-
nary or higher-level n-ary relationship is transformed ....
Database Modeling & Design Fourth Edition- P25 doc
... A -> B. In the preceding example from Figure
6.2, let us assume we are given the following functional dependencies
for the table report:
report: report_no -> editor, dept_no
dept_no -> ... a transitive FD in report is the following:
report_no -> dept_no
dept_no -> dept_name
Therefore we can derive the FD (report_no -> dept_name), since
dept_name is transitively dependent ......
Database Modeling & Design Fourth Edition- P26 doc
... is to find the data somewhere outside the database and insert
it back into the database. All three of these anomalies represent prob-
lems to database designers, but the delete anomaly is by far ... 6.3. The FDs for these
2NF tables are:
report1: report_no -> editor, dept_no
dept_no -> dept_name, dept_addr
report2: author_id -> author_name, author_addr
report3: report_no, author...
Database Modeling & Design Fourth Edition- P30 docx
... with MVDs A ->>
B and CD ->> EF. The first decomposition of R is into two tables R1(A,B)
and R2(A,C,D,E,F) by applying the MVD A ->> B and its complement
A->>CDEF. Table ... CD ->> EF and its
complement CD ->> A. Both R21 and R22 are now 4NF. If we had
applied the MVD complement rule in the opposite order, using CD ->>
EF and its complement CD ->&g...
Database Modeling & Design Fourth Edition- P31 docx
... growth should be estimated, as each
will have significant effect on the later stages of database design.
7.1.1 Design Problems
1. Using the information given and, in particular, the five assertions,
derive ... relationship.
a. one-to-one-to-one => three overlapping composite keys, at
least BCNF
b. one-to-one-to-many => two overlapping composite keys, at
least BCNF
c. one-to-many-t...
Database Modeling & Design Fourth Edition- P36 doc
... 2002]. Table 8.2 shows a data warehouse bus for the four busi-
ness processes in our dimensional design example. Each row represents a
business process. Each column represents a dimension. Each ... compared across business pro-
cesses, the result is meaningful.
The data warehouse bus also makes some design decisions more
obvious. We have taken the liberty of choosing the dimensions for th...
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