Database Reference
In-Depth Information
Insert level, this operation results in cre-
Connect attribute to fact, this operation
ation of a new version of the data ware-
house and it extends the dimensional
schema of the data warehouse by adding
a new dimension level to it. For example,
according to the new education system of
Sweden, each semester system is divided
into two learning periods. To handle adap-
tation to this new education system a new
level (learning period) should be added to
the dimensional schema, as shown later on
in the example of figure 8;
Delete level, this operation results in cre-
results in the creation of a new version of
the data warehouse and it modifies the di-
mensional schema of the data warehouse
by connecting attribute to fact;
Disconnect attribute from fact, this opera-
tion results in creation of a new version
of the data warehouse and it modifies the
dimensional schema by disconnecting at-
tribute from fact.
Insert classification relationship, this op-
eration results in the creation of a new ver-
sion of the data warehouse and it inserts
a classification relation to the dimensional
schema of the data warehouse.
Delete classification relationship, this op-
ation of a new version of data warehouse
and it squeezes the dimensional schema of
the data warehouse by deleting a dimension
level from it. For example, departments
may be dissolved and programs directly
offered by schools. To handle this change,
the level (department) should be deleted
from dimensional schema, as shown later
in the example of figure 8.
Insert attribute, this operation results in
eration results in the creation of a new ver-
sion of the data warehouse and it deletes a
classification relation from the dimensional
schema of the data warehouse.
Insert fact, this operation results in creation
of a new version of the data warehouse and
it extends the fact table of the dimensional
schema by inserting a new fact.
Delete fact, this operation results in the
creation of a new version of the data ware-
house and it extends the dimensional sche-
ma of the data warehouse by inserting an
attribute to it. An example is the addition
of complexity level to the course dimen-
sion in Figure 8;
Delete attribute, this operation results in
creation of a new version of the data ware-
house and it squeezes the fact table of the
dimensional schema by deleting a fact
from it.
versioning graph
the creation of a new version of the data
warehouse and it squeezes the dimensional
schema of the data warehouse by delet-
ing an attribute. For example, removal of
course description attribute from course
dimension in Figure 8;
Connect attribute to dimension level, this
A graphical representation is based on a set of
graphical notations that facilitates using, under-
standing and management of systems (Kitano,
2003). Therefore, GUI-based systems are widely
demanded worldwide. So, in order to, a) know
about the number of versions of data to get a
high-level view of versions; b) identify relation-
ships between versions of the data warehouse
to identify dependencies; c) track versioning
history and to easily navigate between versions;
and d) to identify the active version of the data
operation results in the creation of a new
version of the data warehouse by connect-
ing attribute to dimension level;
Disconnect attribute from dimension level,
this operation results in the creation of a new
version of the data warehouse by removing
an attribute from a dimension level;
Search WWH ::




Custom Search