A PivotCache (section 2.2.5.3) is
specified to be an OLAP PivotCache if
it has an associated PivotTable view (section 2.2.5.3.3) that is
an OLAP PivotTable view (section 2.2.5.4.2).
An OLAP PivotCache MUST have exactly one associated
PivotTable view.