Data Warehouse Concepts - Data Warehouse Systems: Design and Implementation - page 65

SORT(SalesByQuarter, Time, Quantity DESC)

sorts the members of the Time dimension on descending order of the Quantity
measure.
The pivot (or rotate ) operation rotates the axes of a cube to provide an
alternative presentation of the data. The syntax of the operation is as follows:

PIVOT(CubeName, (Dimension → Axis)*)

where the axes are specified as { X, Y, Z, X1, Y1, Z1, . .. } .Thus,theexample

illustrated in Fig. 3.4 e is expressed by:

PIVOT(Sales, Time → X, Customer → Y, Product → Z)

The slice operation removes a dimension in a cube, that is, a cube of
n − 1 dimensions is obtained from a cube of n dimensions. The syntax of this

operation is:

SLICE(CubeName, Dimension, Level = Value)

where the Dimension will be dropped by fixing a single Value in the Level .
The other dimensions remain unchanged. The example illustrated in Fig. 3.4 f
is expressed by:

SLICE(Sales, Customer, City = ' Paris ' )

The slice operation assumes that the granularity of the cube is at the specified
level of the dimension (in the example above, at the city level). Thus, a
granularity change by means of a ROLLUP or DRILLDOWN operation is often
needed prior to applying the slice operation.
The dice operation keeps the cells in a cube that satisfy a Boolean
condition Φ . The syntax for this operation is

DICE(CubeName, Φ )

where Φ is a Boolean condition over dimension levels, attributes, and
measures. The DICE operation is analogous to the relational algebra selection
σ Φ ( R ), where the argument is a cube instead of a relation. The example
illustrated in Fig. 3.4 g is expressed by:

DICE(Sales, (Customer.City = ' Paris ' OR Customer.City = ' Lyon ' )AND
(Time.Quarter = ' Q1 ' OR Time.Quarter = ' Q2 ' ))

The rename operation returns a cube where some schema elements or
members have been renamed. The syntax is:

RENAME(CubeName, ( { SchemaElement | Member }→ NewName)*)

For example, the following expression

RENAME(Sales, Sales → Sales2012, Quantity → Quantity2012)

renames the cube in Fig. 3.4 a and its measure. As another example,