A query optimization method based on join index in data warehouse

A technology for connecting indexes and data warehouses, which is applied in the field of query processing, and can solve problems such as the increase in the calculation cost of the bitmap of the number of values, the high update frequency, and the large cost of index storage space, so as to reduce storage costs and maintenance costs, and achieve good performance Effect
CN104866608BActive Publication Date: 2018-01-09RENMIN UNIVERSITY OF CHINA
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
RENMIN UNIVERSITY OF CHINA
Publication Date
2018-01-09

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Abstract

The invention relates to a query optimization method based on a connection index in a data warehouse. The steps are: creating a connection index of a fact table foreign key based on a dimension table proxy key; creating a connection index update strategy; when there is a predicate condition on the dimension table, through the connection After the index directly accesses the dimension table records, it needs to judge the predicate, and refer to the bitmap connection index to generate the connection bitmap index through dynamic bitmap connection index calculation; when the selection rate on the dimension table is very low, the dimension table bitmap is further compressed to improve the dimensionality. The cache level of the table bitmap calculation; the calculation method of the reference bitmap connection index based on the coprocessor memory calculation is adopted, and only the array and the bitmap data structure are used to calculate the simple memory address access. The invention can effectively improve the computing performance of the bitmap index, and can be combined with high-performance coprocessors such as GPU and Xeon PhiTM to accelerate the computing performance of the index, and can be widely used in the field of data warehouses.
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Description

technical field

[0001] The invention relates to a query processing method in the field of various data warehouses, in particular to a query optimization method based on a join index in a data warehouse. Background technique

[0002] A data warehouse is a complex data set based on a multidimensional data model. When processing a database-based OLAP (Relational OLAP, ROLAP) query, it is necessary to connect the fact table and multiple dimension tables to execute complex analysis and query commands. The performance of the connection operation has been the most important problem in analytical query processing (OLAP). A connection index is an index that creates a connection relationship between two or more table records through pre-connection, and the connection index records the address relationship of connection records between different tables. During query processing, the address of the connection record of the two tables can be directly obtained through the connection index...

Claims

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