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Table 2. Classification of approaches
Versioning
Evolution
Schema and Instance
Eder et al., Malinowski et al.
Hurtado et al., Kaas et al.
Schema only
Golfarelli et al.
Blaschka et al., Quix
Instance only
SAP AG, Ravat et al., Sarda, Body et al.
Kimball, Yang et al, Kalido
the biggest flexibility. On the other hand, it can
be seen that the current commercial approaches
both support maintenance only on instance level.
But nevertheless, selection considering these
two features only may not be sufficient. Table
3 compares some the approaches (two of them
quite established and two rather new ones) with
respect to a set of additional features. The selec-
tion of approaches for the comparison is based on
their similarity, i.e. the selected approaches follow
similar principles, which allows to define a set of
features applicable to all of them. A plus in a cell
expresses that the respective approach supports
the feature. A minus means that the respective
feature is not supported by that approach.
3.
Data transformation or multiversion
queries:
Does the approach support que-
ries spanning several structure versions or
transformation of cell data between structure
versions?
4.
Complex Operations:
Does the approach
support operations other then insert, delete,
update (for instance split or merge)?
5.
Formal Temporal Model:
Is a formal model
for the temporalization provided?
6.
Changes in Time/Fact dimension:
Does the
approach allow changes in the Time and/or
Fact dimension?
7.
Modeling Technique:
Is the approach based
on a particulare technique for multidimen-
sional modeling, possibly presented by the
authors?
1.
Valid time for hierarchical relations:
Does
the approach support valid time for the rela-
tions between dimension members?
Related Problems
2.
Valid time for dimension members:
Does
the approach support valid time for dimen-
sion members?
Besides the classical maintenance requirements
of keeping managing structural changes in a data
Table 3. Features of different maintenance approaches
Eder
et al.
Hurtado et al.
Golfarelli et al.
Malinowski et al.
Valid time for hierarchical relations
+
+
+
+
Valid time for dimension members
+
-
-
+
Data transformation / multiversion queries
+
-
+
-
Complex
operations
+
+
-
-
Formal Temporal Model
+
+
+
+
Changes in Time/Fact dimension
+
-
+
-
Modelling
Technique
-
-
+
+
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