See you soon, why SHOW TABLE STATUS never updates

Did you tread a hole? 1. Problem Description 2. Problem Exploration 3. Summary 4. Extended Reading 1. Description of the problem A few days ago, the QQ group was discussing a delayed update of M ...

Posted on Sun, 07 Jun 2020 18:11:50 -0700 by TeamTJ

(10) Haproxy + preserved build Mycat cluster to achieve high availability

We can use haproxy + preserved with two Mycat to build a Mycat cluster to achieve high availability. HAProxy It realizes the cluster high availability and load balancing of MyCat, The high availability of HAProxy itself can be achieved through Keepalived.   Node description node ...

Posted on Sun, 07 Jun 2020 03:12:10 -0700 by Clarkeez

Tree production into forest -- binary tree, binary sorting tree, balanced binary tree, B tree, B + tree

Tree structure is not new to everyone, but there are several trees that are really applied to the code - binary sorting tree, balanced binary tree, B tree, B + tree, red and black tree. Whether you know it or not, today, after reading this blog, you will plant it in front of your home. Binary tree def ...

Posted on Sun, 07 Jun 2020 01:31:13 -0700 by srikanthiv

Chapter four (index calculation) of hundreds of billions of warehouses_ User order indicator business development)

User order indicator business development 3.1 demand analysis E-commerce platforms often need to analyze users' behaviors according to their purchase data. We make some statistical analysis based on the user's order situation for future user behavior analysis. According to the consumer behavior of users ...

Posted on Fri, 05 Jun 2020 01:04:27 -0700 by bakaneko

Page single hop conversion module

1, Demand analysis 1. Get the taskid from the spark submit script submitted by the user and get the parameters of the task 2. Obtain the data within the specified date range for calculation, and obtain the page slice flow to calculate the conversion ratio of visits between pages. Like targe tPageFlow: ...

Posted on Fri, 05 Jun 2020 00:03:52 -0700 by defunct

MyBatis: Reverse Engineering

catalog 1, What is reverse engineering? 2, Characteristics of MyBatis reverse engineering 1. Advantages of MyBatis reverse engineering 2. Disadvantages of MyBatis reverse engineering 3, MyBatis reverse engineering construction 1. Add dependency pom.xml 2. Create MBG profile generatorConfig.xml 3. ...

Posted on Thu, 04 Jun 2020 06:45:24 -0700 by millsy007

[Centos] deploy the helpingscheduler from scratch

1. Environment configuration Install JAVA 1.8 / MySQL 5.7 / ZooKeeper 3.5.8 1.1 installing JAVA 1.8 Check whether there is an installation. If there is one, delete it first rpm -qa | grep java # java-1.7.0-openjdk-1.7.0.71-2.5.3.1.el7_0.x86_64 rpm -e --nodeps java-1.7.0-openjdk-1.7.0.71-2.5.3.1.e ...

Posted on Tue, 02 Jun 2020 19:45:11 -0700 by dsjoes

A detailed explanation of view sequence synonym index in Oracle

1, View 1. What is a view In short, a view is a virtual table, a mapping of entity tables       When to use views In development, there are some table structures that do not want too many people to contact, so entity tables are mapped to a view. (simplified table structure) In the process of project, programmers main ...

Posted on Tue, 02 Jun 2020 07:40:40 -0700 by thomasanup

Detailed explanation of single line function operation in Oracle

Single line function -- PL/SQL (1) Character function Function number Say clearly  CONCAT Concatenate two strings, same as |  INITCAP Change the first letter of the string to uppercase  INSTR Find the position of a string  LENGTH Give the length of the string in characters   ...

Posted on Sun, 31 May 2020 08:55:23 -0700 by rushenas

type column parsing of explain

1,const Indicates that the execution step returns at most one row of data. const usually appears in the equivalent query of the primary key or unique index, such as the equivalent query of the primary key id of the t table:It can be considered that it is as fast as a rocket to locate a record by comparing the equivalence between the primary key ...

Posted on Sun, 31 May 2020 08:54:20 -0700 by a.heresey