Method and device for creating sparse indexes, sparse index and query method and device

Abstract

The invention discloses a method and a device for creating sparse indexes. For data records to be processed, a same hash function is used for calculating hashed values of key values, the data records are saved into corresponding subareas according to the calculated hashed values, and the data records saved into the same subarea have same hashed values; for any subarea, in the initial phase, the content in the subarea is empty, the saved data records are used for forming a file block when the saved data records reach preset requirements, and the data records not forming the file block are used for forming another file block when the saved data blocks not forming the file block reach preset requirements again, and so on; and an index entry is created for every formed file block. According to the method and the device, the creating speed of sparse indexes can be fastened. The invention discloses a sparse index and a query method and device based on the sparse index simultaneously.

Description

technical field [0001] The invention relates to data processing technology, in particular to a sparse index establishment method and device, a sparse index, and a query method and device based on the sparse index. Background technique [0002] When data is loaded, in order to facilitate subsequent queries, an index is usually established for the data records, and the index may be a dense index or a sparse index. [0003] Among them, the dense index needs to establish an index item for each data record, while the sparse index only needs to establish an index item for each group, and each group includes several data records. [0004] In the prior art, the sparse index is usually established in the following manner: sort the data records to be processed, that is, the data records to be loaded, according to certain rules, such as the order of key values ​​from small to large; Records are segmented to obtain several groups; for each group, an index item is established, each inde...

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Problems solved by technology

[0006] However, the above method has certain problems in practical application, that is, since each data record needs to be sorted before subsequent processing, and the sorting process is very complicated to implement, it will lead to a very slow establishment of the sparse index. slow

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