Hash connecting method for database based on shared Cache multicore processor

A multi-core processor and connection method technology, applied in the direction of electrical digital data processing, special data processing applications, instruments, etc., can solve the problem of low resource utilization and achieve the effect of reducing Cache access conflicts

Inactive Publication Date: 2009-12-02
NAT UNIV OF DEFENSE TECH +2
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  • Description
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Problems solved by technology

[0007] The technical problem to be solved by the present invention is: aiming at the problem that the utilization rate of processor parallel computing resources is low in the current database hash connection in a large memory capacity database server configured with a shared secondary Cache multi-core processor, the present invention provides a Multithreaded Hash Join Processing Method Based on Data Partition

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  • Hash connecting method for database based on shared Cache multicore processor
  • Hash connecting method for database based on shared Cache multicore processor
  • Hash connecting method for database based on shared Cache multicore processor

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Embodiment Construction

[0030] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0031] The multi-thread database hash connection method based on the shared Cache multi-core processor of the present invention includes two steps of connection table division and aggregation connection.

[0032] The first step: join table division. For the two tables (L and R) participating in the connection, the data is divided according to the hash value of the connection column. like figure 1 As shown, the left half of the figure is a frame diagram of the connection table division stage. When the join table division is executed, the temporary table generation module first generates a temporary table, and then the temporary table division module performs data division on the temporary table. Specific steps are as follows:

[0033] A. Obtain the page number set of all pages in the table, then traverse the page number set, calculate the ...

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Abstract

The invention discloses a hash connecting method for database based on a shared Cache multicore processor. The method is divided into a link list division phase and an aggregation connection phase, wherein the link list division comprises the following steps that: firstly, a temporary list is generated through a temporary list generation module; secondly, temporary list division is executed on the temporary list by temporary list division thread; thirdly, before division, a proper data division strategy is determined according to the size of the temporary list; and fourthly, proper start occasion of the temporary list division thread is determined in a process of temporary list division to reduce Cache access collision; in aggregation connection, an aggregation connection execution methodbased on classification of aggregation sizes is adopted, and the memory access in hash connection is optimized. The method ensures that the hash connection sufficiently utilizes operating resources of a multicore processor, and the speedup ratio executed by hash connection is close to the number of cores of the processor so as to greatly shorten the execution time of the hash connection.

Description

technical field [0001] The invention mainly relates to a database query execution technology, in particular to a multi-thread execution optimization method of a database hash connection. Background technique [0002] With the continuous increase of the number of processor transistors, the frequency of the processor has reached the limit under the existing conditions, and the energy consumption is increasing, so the development trend of the processor is shifting from the single-core processor with high main frequency to the multi-core processing on the chip. processor, from relying on instruction-level parallelism to thread-level parallelism. At present, 2-core and 4-core processors are becoming the mainstream of the market, and the number of cores is still increasing, which greatly improves the parallel computing performance of a single processor. Compared with before the popularization of multi-core processors, parallel computing is becoming the main program. mode of opera...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G06F17/30G06F12/08G06F9/38G06F12/084G06F12/0875
Inventor 邓亚丹景宁熊伟陈宏盛陈荦李军陈荣国周成虎张明波程昌秀谢炯卢战伟冯登国徐震张敏陈驰
Owner NAT UNIV OF DEFENSE TECH
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