On Querying Data and Metadata in Multiversion Data Warehouse - Data Warehousing Design and Advanced Engineering Applications - page 223

Figure 4. The example screen shot of the content query interface presenting the result of a MVQ that
addresses versions from March to May

versions. The root of a DW version derivation
tree is yellow-colored. Real DW versions are
blue-colored, whereas alternative DW versions
are red-colored. Regardless a version type, if
a version does not contain the searched object,
then it is gray-colored, otherwise it is colored as
mentioned above.
The example screen shot of the metadata query
interface is shown in Figure 5. Similarly as in the
content query interface , it is composed of the ob-
ject navigator and the query visualizer . Figure 5
displays the results of a version query searching for
DW versions that contain hierarchy H_Product in
dimension Product in base version from February.
Ellipses represent DW versions and arrows repre-
sent derived-from relationships. RV1 , RV2 , and RV3
represent real DW versions, whereas AV31 , AV32 ,
and AV321 represent alternative DW versions.
Detail metadata are displayed after clicking on
the node of the version derivation tree. The meta-
data are visualized in a window shown in Figure
6. It displays four types of metadata, namely: (1)

query information - providing an information on
the executed query (query type, i.e., a version
query or an object evolution query, its base ver-
sion, and the query version range), (2) current
version - providing an information on the DW
version that is represented by the selected node
(the information is retrieved from the VERSIONS
dictionary table), (3) image query object - which is
the graphical visualization of an object specified
in the version query, and (4) query object - which
provides an information on an object specified in
the version query.

Object Evolution Query Visualization

As mentioned before, the result of an object evolu-
tion query is the evolution history of a specified
object. This history is visualized by a DW version
derivation tree (similarly as a version query) but
the derivation tree is augmented by the graphical
representation of the structure of the searched
object.