Index structure based on dictionary tree, data query optimization method, main memory manager

Abstract

The invention discloses an index structure based on a dictionary tree, a data query optimization method and a main memory manager, belonging to the field of data storage. The index structure is composed of containers. The container stores T nodes and S nodes. The complete key is divided into partial keys. The T node stores the first m / 2 bits of the partial key, and the S node stores the last m / 2 bits of the partial key. From the dictionary tree The partial keys passed on the path from the root node to a certain node are connected to form a complete key. The index structure is more compact, thereby improving the utilization rate of main memory space. Use jump successor to directly jump T node to subsequent brother node, thereby reducing the number of comparisons and improving search performance; use T node jump table to jump T node to S node, use container jump table to jump S node to T node, Jump directly to the nearest target, thereby skipping a large number of unnecessary entries and improving the search performance. The pointer P containing the IDs of each hierarchical structure parsed by the main memory manager fully decouples the index structure from the main memory address.

Description

technical field [0001] The invention belongs to the technical field of data storage, and more specifically relates to a dictionary tree-based index structure, a data query optimization method, and a main memory manager. Background technique [0002] At this stage, due to the impetus of Moore's Law, the capacity of data and disks is growing rapidly, while the capacity of DRAM (Dynamic Random Access Memory, hereinafter collectively referred to as "main memory") is growing relatively slowly. In the face of massive data, DRAM has become the bottleneck of system performance, and improving the storage capacity space utilization of DRAM is crucial to improving the overall performance of the system. Due to the limitation of the main memory capacity, massive indexes cannot be completely stored in the main memory, and are often partially stored in secondary storage devices, such as disks or solid-state disks. However, the high I / O latency of the above-mentioned secondary storage devic...

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Problems solved by technology

[0005] Aiming at the defects of the prior art, the purpose of the present invention is to solve the technical problem of the low utilization rate of the main memory space by the index structure in the prior art

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