Query method and device based on distributed database

A query method and technology of a query device, applied in the database field, can solve problems such as low query efficiency, and achieve the effects of reducing implementation difficulty, reducing crashes, and improving query efficiency

Active Publication Date: 2022-05-24
北京东方国信科技股份有限公司
View PDF4 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] Embodiments of the present invention provide a query method and device based on a distributed database to solve or at least partly solve the problem of low efficiency of query in the prior art

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Query method and device based on distributed database
  • Query method and device based on distributed database
  • Query method and device based on distributed database

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0048] In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0049] In order to overcome the above problems of the prior art, an embodiment of the present invention provides a query method based on a distributed database, the inventive concept of which is that participating nodes perform replacement of query results of scalar sub-queries, and generate an outer layer of scalar sub-queries. The...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

Embodiments of the present invention provide a query method and device based on a distributed database. Wherein, the method includes: for an original SQL query statement including several scalar subqueries, according to the parsing tree of the original SQL query statement, generate a sub-execution plan and auxiliary execution code corresponding to each scalar sub-query; The sub-execution plan and auxiliary execution code are sent to the corresponding participating nodes; the execution results of each outer SQL statement containing scalar subqueries are obtained, and the original SQL query is obtained according to the execution results of each outer SQL statement including scalar subqueries The result of executing the statement. The distributed database-based query method and device provided by the embodiments of the present invention send the sub-execution plans and auxiliary execution codes corresponding to each scalar sub-query to the participating nodes, so that the replacement of the query results of the scalar sub-queries of the master node is distributed to Each participating node can simplify the query steps and improve query efficiency.

Description

technical field [0001] The present invention relates to the technical field of databases, and more particularly, to a query method and device based on a distributed database. Background technique [0002] Structured Query Language (SQL, Structured Query Language) is a special programming language. Structured Query Language is used to store data and to query, update, and manage database systems. [0003] A subquery is a query in an SQL statement that is nested within another query. This other query is called a raw SQL query. Subqueries can dynamically adjust the execution of the subqueries themselves based on the contents of the tables in the original SQL query. This technique makes the SQL language more flexible and expressive. [0004] A subquery returns a collection. This set can be used in from / with statements or as operands to operators such as the in / exists operator / keyword. If the result returned by a subquery contains only one row of data, and this row of data h...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Patents(China)
IPC IPC(8): G06F16/2453G06F16/27
CPCG06F16/24534G06F16/27
Inventor 董隆超孔令雷周伟张娇娇
Owner 北京东方国信科技股份有限公司
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap