Data query method, device and system based on OLAP system

Abstract

The embodiment of the invention provides a data query method, device and system based on an OLAP system. The data query method includes the steps that a data query request sent by a user terminal is received, a first data table corresponding to first data table identification is partitioned logically to obtain at least two first partitions, and a corresponding connection mapping relation is built for each first partition; a second data table corresponding to second data table identification is partitioned logically to obtain at least two second partitions, a first foreign key value is obtained from each second partition, and the first foreign key values are within the boundary value range of the first partitions; the connection mapping relations are queried to obtain a first Hash subtable corresponding to the first foreign key values; the first Hash subtable is scanned to obtain corresponding data, and the data are returned to the user terminal. According to the data query method, through setting up the connection mapping relations, data query time is effectively shortened, and overhead of a server is reduced.

Description

technical field [0001] Embodiments of the present invention relate to computer technology, and in particular to a data query method, device and system based on an On-Line Analytical Processing (OLAP) system. Background technique [0002] As a typical application scenario of the database system, OLAP is mainly used to query data. In the process of querying data, it often involves joint query of multiple data tables. Tables need to be associated through connection operations. , a common join operation is a hash join. [0003] In the prior art, the method of data query using hash join is mainly as follows: the background server of the database system receives the data query message sent by the user, and according to the first data table identifier and the second data table identifier carried in the data query message, , perform a hash operation on the primary key of the first data table with a small number of rows, establish a shared hash table, and then perform a parallel sca...

AI Technical Summary

Problems solved by technology

[0005] Embodiments of the present invention provide a data query method, device, and system based on an OLAP system to overcome the problems of long multi-threaded query time and high server overhead in the prior art, by partitioning the first data table and the second data table , and establish a connection mapping relationship. In the process of multi-thread query, each thread obtains and scans the first hash subtable through the connection mapping relationship, thereby obtaining data, effectively shortening the data query time and reducing server overhead.

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