Interpretation of New Features| MySQL 8.0 Resource Group
Originator: Yang Taotao
Before MySQL 8.0, let's assume there was a bad SQL.
mysql
select * from t1 order by rand() ;
Running with multiple threads, causing the CPU to run full and other requests to be blocked.What about this?(
There are probably several solutions:
Set max_execution_time to prevent reading SQL for too long.The poss ...
Posted by thebay on Mon, 22 Jul 2019 05:02:03 +0200
json data interaction implemented by servlet+ajax
Need plug-in Jquery, jar packages: json-lib-2.2.3-jdk15.jar and other jar packages are as follows:
1. Front desk js+html code
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
&l ...
Posted by elle_girl on Sun, 21 Jul 2019 09:46:22 +0200
mybatis Section 7 One-to-One Association
1.1. Requirements
Query class information based on class id (with teacher's information)
1.2. Creating tables and data
Create a table of teachers and classes. Let's assume a teacher teaches only one class. The relationship between teachers and classes is one-to-one.
1.3 sql statement
CREATE TABL ...
Posted by kdidymus on Sat, 20 Jul 2019 05:24:24 +0200
Migrating from Oracle ASMLIB to ASM Filter Driver
ASM Filter Driver is a new function that can replace ASMLIB and udev settings. It can replace ASMLIB and manual settings of udev rules files, and most importantly, I/O Filter functions. The so-called I/O Filter function can reject all invalid I/O requests. The main function is to prevent accidental overwriting of the underlying disk of the ASM ...
Posted by ruiner17 on Fri, 19 Jul 2019 13:04:51 +0200
Sharing Repository Pattern Design Based on EF6, Unitwork and Autofac
Catalog
Sharing Repository Pattern Design Based on EF6, Unitwork and Autofac
I. Ideas and Structural Diagrams for Realization
2. Repository Design Specific Implementation Code
3. Specific Use of Repository Design
4. Summary of Thoughts
5. Case source code
Sharing Repositor ...
Posted by glennn3 on Fri, 19 Jul 2019 07:43:29 +0200
Spring-Boot integrates mybatis(1), using the default database connection pool
Recently, I've been busy, I haven't written a blog for a long time. Sorry, the springboot project used JPA standard. It was implemented by hibernate. The latest trend is to try to integrate mybatis with springboot. So I found the official documents to configure it. Here's the text.
First of all, introduce the development environment:
...
Posted by vietnamese on Wed, 17 Jul 2019 21:39:22 +0200
Composite data types for MySQL: ENUM and SET
Common data types for MySQL include Number/Date/String, which includes simple data types of different lengths, such as Char/Varchar/Binary/blob/text. Sometimes we need more detailed data management, such as enumerations and collections, and composite types ENUM and SET.
ENUM Enumeration Type
ENUM is suitable for scenarios where only one of a s ...
Posted by iRock on Wed, 17 Jul 2019 18:18:35 +0200
Building Simple Windows Services Using Topshell Components
Many times we are discussing whether we need to understand the underlying principles of a component or a language. In fact, I personally feel that everyone has their own views on this issue, and the way they choose will be different depending on their personal circumstances. I personally feel that no matter what we learn, we should try to under ...
Posted by SilveR316 on Tue, 16 Jul 2019 19:32:12 +0200
Two ways to set up Oracle DataGuard
Oracle introduced the ADG (Active DataGuard) read-only mode DataGuard in 11g version to replace the DG mode in 10g, which can only be mount ed but cannot be opened. There are also some improvements in the way of building. This article lists two different ways of building and their differences in detail.
General description of two DG constr ...
Posted by fredroines on Tue, 16 Jul 2019 18:34:20 +0200
Split database table fields, rebuild tables with splitted fields and delete associated tables
#!/bin/bash
#author xiaobao
#date 2017-3-24 21:37:27
#The principle of this sql is:
#1. Create t_prog_test table
#2. The value of file_name field in t_file_bak table is divided into four parts, and the values are inserted into course_id, student_id, sub_id and extra of t_prog_test table, respectively.
#3. If the extra value is no ...
Posted by orison316 on Tue, 16 Jul 2019 02:56:58 +0200