Short note on Hybrid online analytical processing (HOLAP) .

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HOLAP

  • Hybrid online analytical processing (HOLAP) is a combination of relational OLAP (ROLAP) and multidimensional OLAP (usually referred to simply as OLAP). HOLAP was developed to combine the greater data capacity of ROLAP with the superior processing capability of OLAP.
  • HOLAP can use varying combinations of ROLAP and OLAP technology. Typically it stores data in both a relational database (RDB) and a multidimensional database (MDDB) and uses whichever one is best suited to the type of processing desired. The databases are used to store data in the most functional way. For data-heavy processing, the data is more efficiently stored in an RDB, while for speculative processing, the data is more effectively stored in an MDDB.
  • HOLAP users can choose to store the results of queries to the MDDB to save the effort of looking for the same data over and over which saves time. Although this technique - called "materializing cells" -improves performance, it takes a toll on storage. The user has to strike a balance between performance and storage demand to get the most out of HOLAP. Nevertheless, because it offers the best features of both OLAP and ROLAP, HOLAP is increasingly preferred.


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