OptimizeCache Property [Excel 2003 VBA Language Reference]
True if the PivotTable cache is optimized when it's constructed. The default value is False. Read/write Boolean.
Cache optimization results in additional queries and degrades initial performance of the PivotTable report.
For OLE DB data sources, this property is read-only and always returns False.
This example causes the PivotTable cache for the first PivotTable report on worksheet one to be optimized when it's constructed.
Worksheets(1).PivotTables("Pivot1") _ .PivotCache.OptimizeCache = True