Coder Social home page Coder Social logo

Comments (2)

yangsishu avatar yangsishu commented on August 20, 2024

就是通过数字 取模

from chunjun.

coolsummery avatar coolsummery commented on August 20, 2024

JDBC 读数据 通过 JdbcInputFormatBuilder.setParameterValues(Object[][] parameterValues)来配置并发读,就是原理不是很明白。只能看出sql 语句中 通过 where mod(splitKey, 并发数 N) = [0,1,2...N-1] 可以把结果集分成N份,其它的实现就不知道了。
哪位大佬有空,请帮忙理理实现思路。万分感谢!

我理解是这样的,首先会生成并发数N个subtask,然后每个task都会去所有的表中进行一次查询,类似这样
subtask1 执行 select * from db1.tb1 where mod(splitKey,并发数N) = 1
subtask2 执行 select * from db1.tb1 where mod(splitKey,并发数N) = 2
subtask1 执行 select * from db1.tb2 where mod(splitKey,并发数N) = 1
subtask2 执行 select * from db1.tb2 where mod(splitKey,并发数N) = 2
这样,单张表的查询次数就是N次。

from chunjun.

Related Issues (20)

Recommend Projects

  • React photo React

    A declarative, efficient, and flexible JavaScript library for building user interfaces.

  • Vue.js photo Vue.js

    🖖 Vue.js is a progressive, incrementally-adoptable JavaScript framework for building UI on the web.

  • Typescript photo Typescript

    TypeScript is a superset of JavaScript that compiles to clean JavaScript output.

  • TensorFlow photo TensorFlow

    An Open Source Machine Learning Framework for Everyone

  • Django photo Django

    The Web framework for perfectionists with deadlines.

  • D3 photo D3

    Bring data to life with SVG, Canvas and HTML. 📊📈🎉

Recommend Topics

  • javascript

    JavaScript (JS) is a lightweight interpreted programming language with first-class functions.

  • web

    Some thing interesting about web. New door for the world.

  • server

    A server is a program made to process requests and deliver data to clients.

  • Machine learning

    Machine learning is a way of modeling and interpreting data that allows a piece of software to respond intelligently.

  • Game

    Some thing interesting about game, make everyone happy.

Recommend Org

  • Facebook photo Facebook

    We are working to build community through open source technology. NB: members must have two-factor auth.

  • Microsoft photo Microsoft

    Open source projects and samples from Microsoft.

  • Google photo Google

    Google ❤️ Open Source for everyone.

  • D3 photo D3

    Data-Driven Documents codes.