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📜  ROLAP，MOLAP和HOLAP之间的区别

📅  最后修改于: 2020-12-30 00:49:02             🧑  作者: Mango

ROLAP，MOLAP和HOLAP之间的区别

ROLAP MOLAP HOLAP
ROLAP stands for Relational Online Analytical Processing. MOLAP stands for Multidimensional Online Analytical Processing. HOLAP stands for Hybrid Online Analytical Processing.
The ROLAP storage mode causes the aggregation of the division to be stored in indexed views in the relational database that was specified in the partition’s data source. The MOLAP storage mode principle the aggregations of the division and a copy of its source information to be saved in a multidimensional operation in analysis services when the separation is processed. The HOLAP storage mode connects attributes of both MOLAP and ROLAP. Like MOLAP, HOLAP causes the aggregation of the division to be stored in a multidimensional operation in an SQL Server analysis services instance.
ROLAP does not because a copy of the source information to be stored in the Analysis services data folders. Instead, when the outcome cannot be derived from the query cache, the indexed views in the record source are accessed to answer queries. This MOLAP operation is highly optimize to maximize query performance. The storage area can be on the computer where the partition is described or on another computer running Analysis services. Because a copy of the source information resides in the multidimensional operation, queries can be resolved without accessing the partition’s source record. HOLAP does not causes a copy of the source information to be stored. For queries that access the only summary record in the aggregations of a division, HOLAP is the equivalent of MOLAP.
Query response is frequently slower with ROLAP storage than with the MOLAP or HOLAP storage mode. Processing time is also frequently slower with ROLAP. Query response times can be reduced substantially by using aggregations. The record in the partition’s MOLAP operation is only as current as of the most recent processing of the separation. Queries that access source record for example, if we want to drill down to an atomic cube cell for which there is no aggregation information must retrieve data from the relational database and will not be as fast as they would be if the source information were stored in the MOLAP architecture.

ROLAP和MOLAP之间的区别

ROLAP MOLAP
ROLAP stands for Relational Online Analytical Processing. MOLAP stands for Multidimensional Online Analytical Processing.
It usually used when data warehouse contains relational data. It used when data warehouse contains relational as well as non-relational data.
It contains Analytical server. It contains the MDDB server.
It creates a multidimensional view of data dynamically. It contains prefabricated data cubes.
It is very easy to implement It is difficult to implement.
It has a high response time It has less response time due to prefabricated cubes.
It requires less amount of memory. It requires a large amount of memory.