PATTERNS OF DATA MODELING- P28 pot
PATTERNS OF DATA MODELING- P28 pot
... characterization of a common software flaw. The antipatterns in Table 9.1
simplify reading but compromise the ability of database structure to enforce quality. These
antipatterns are often acceptable for data ... (FK)
accountEquivalenceID
AccountEquivalence
tangibleActorID
TangibleActor
. . .
118 Chapter 9 / Non -Data- Warehouse Antipatterns
into a single dimension entity. For example,...
PATTERNS OF DATA MODELING- P6 potx
... Software Architecture: A System of Patterns. Chichester, United Kingdom:
Wiley, 1996.
[Chen-1976] PPS Chen. The entity-relationship model—toward a unified view of data. ACM Transac-
tions on Database ... Vlissides. Design Patterns: El-
ements of Reusable Object-Oriented Software. Boston, Massachusetts: Addison-Wesley, 1995.
[Hay-1996] David C. Hay. Data Model Patterns: Conventions...
PATTERNS OF DATA MODELING- P8 potx
... branch nodes. A Tree is a hierarchy of nodes and has one node as the root.
A particular node may, or may not, be the root. You need not show Tree in a use of the tem-
plate.
A Node is either ... nodes each of which, in turn, can be a leaf node or a further branch node.
Figure 2.18 adds the constraint that a tree cannot have any cycles. (See Section 2.2.1 for
an explanation of cycles.)...
PATTERNS OF DATA MODELING- P10 potx
... a person can be manager of one group and an acting manager of another group. The
same person may be an individual contributor and a manager during different portions of a
Figure 2.36 Tree changing ... differ from that of its various positions.
A Tree is a hierarchy of nodes and has one node as the root. A Node is a position within
a Tree. An Entity is something with identity and da...
PATTERNS OF DATA MODELING- P13 potx
... (directed graph) is a set of nodes and a set of directed edges that connect nodes.
(Note: in a directed graph all nodes do not have to be connected.) You need not show DG in
a use of the template. A ... represented via the coupling between nodes. The populated tables use different
data than Figure 3.1 because the premise of the template is a tree that is generalized to having
multip...
PATTERNS OF DATA MODELING- P14 pot
... published de-
scription of air travel between two airports. The frequency indicates the days of the week for
which the PublishedFlight applies. A PublishedFlight consists of a sequence of Published-
FlightLegs ... Directed Graph Template 49
A DG (directed graph) is a set of nodes and a set of directed edges that connect nodes.
You need not show DG in a use of the template. A Nod...
PATTERNS OF DATA MODELING- P19 potx
... background for data and a light gray for metadata.
The item description template is useful if you cannot fully describe data as software is
being developed. The template lets you enter data and its ... Item description: UML template. Use when the same model
relates data and metadata.
ItemDescription Item
Characterization Metadata Data
Flexibility General purpose Specific
Volatility...
PATTERNS OF DATA MODELING- P30 pot
... 10.17, Figure 10.18). The notion of
an event often appears in application models. An EventType is a general category of Events.
This archetype involves data and metadata and uses the shading convention ... the
definition of events by their similarities and differences using generalization.
There is also a simple model of cause and effect. A group of causes might lead to a group
o...
PATTERNS OF DATA MODELING- P33 pot
... that the combination of fields will be unique. I strongly encourage the use
of candidate keys. After all, the purpose of a database is not only to store data but also to
assure data s quality. When ... to find data in a database or the database is compromised.
11.1 Intrinsic Identity
Intrinsic identity is the ability to find data with fields that have meaning. Starting from out-...
PATTERNS OF DATA MODELING- P34 potx
... acquisitions that cause databases to be merged. For example, the merger of Delta
Airlines and Northwest Airlines created a need to merge frequent flyer databases.
The tricky part of merging data is determining ...
entities remain in the
database. Gradually
migrate data to the
active entity.
• Eventually con-
solidates the data.
• There is less risk
of stale references
as obso...
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