HOLAP
From Wikipedia, the free encyclopedia
HOLAP (Hybrid Online Analytical Process) is a combination of ROLAP and MOLAP which are other possible implementation of OLAP. HOLAP allows to store part of the data in the MOLAP store and another part of the data in ROLAP store. The degree of control that cube designer has over this partitioning varies from product to product.
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[edit] Vertical partitioning
In this mode HOLAP stores aggregations in MOLAP for fast query performance, and detailed data in ROLAP to optimize time of cube processing.
[edit] Horizontal partitioning
In this mode HOLAP stores some slice of data, usually the more recent one (i.e. sliced by Time dimension) in MOLAP for fast query performance, and older data in ROLAP.
[edit] Products
Examples of commercial products which support HOLAP storage mode are Microsoft Analysis Services and MicroStrategy. Now SAP_AG Supports HOLAP with BI Accelerator.
[edit] External links
Owen Kaser and Daniel Lemire, Attribute Value Reordering for Efficient Hybrid OLAP, In DOLAP'03, New Orleans, Louisiana, November 7, 2003.
