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5
Oracle Dimension Objects
This chapter examines Oracle dimension objects. In a star schema, dimen-
sions are denormalized into a single layer of dimensions. In a snowflake
schema, dimensions are normalized out to multiple hierarchical layers.
Dimension objects can be used to represent these multiple layers for both
star and snowflake schemas, possibly helping to increase performance of
joins across dimension hierarchies.
Note:
This chapter uses a number of example dimensional structure hierar-
chies in order to demonstrate the widely variable applicability of dimen-
sional objects.
5.1 What Is a Dimension Object?
In a data warehouse a dimension, ...