MySQL stored procedures and functions

1. Stored procedures and functions 1.1 overview of stored procedures and functions Stored procedures and functions are a collection of SQL statements compiled and stored in the database in advance. Calling stored procedures and functions can simplify a lot of work of application developers and reduce the transmission of data between the datab ...

Posted by vietnamese on Wed, 09 Mar 2022 14:49:08 +0100

MySQL has too much replication delay due to insufficient IO capacity

background Received alarm, content: MySQL_ The master-slave replication delay is too high (example: XXXX), current value: 1032.00, threshold: 1000 - 100000000, occurrence time: 12 / 30 / 2021 02:27:16. Analysis process Generally, in case of replication delay, let's first look at the replication status and active session of the slave library. ...

Posted by swasheck on Wed, 09 Mar 2022 02:35:03 +0100

EXPLAIN introduction

catalogue Test data preparation Build table Initialization data How to use EXPLAIN Attribute analysis id select_type table column type possible_key,key key_len ref rows filtered Extra EXPLAIN statement provides information about how MySQL executes SQL. It is an artifact of SQL optimization that we must master. EXPLAIN on the o ...

Posted by jayd1985 on Tue, 08 Mar 2022 20:00:24 +0100

MyBatis simple instructions

First, briefly explain the use of MyBatis, and then focus on several core principles of MyBatis. MyBatis easy to use MyBatis can be divided into the following key points Introducing MyBatis dependency Configure mybatis config XML configuration file Create database entity class and Mapper mapping file Load the configuration through S ...

Posted by rahuul on Tue, 08 Mar 2022 09:04:35 +0100

. Net/C# sub database and sub table high performance O waterfall flow paging

Frame introductionAccording to the Convention, first introduce the protagonists of this issue: ShardingCore A high-performance, lightweight solution for reading and writing separation of tables and databases under ef core, with zero dependency, zero learning cost and zero business code intrusionThe only fully automatic sub table and multi field ...

Posted by oneofayykind on Tue, 08 Mar 2022 03:46:52 +0100

3, Index optimization analysis

1. Reasons for performance degradation and slow SQL query ① Low performance of query statements; ② Index failure single value / composite index; ③ Too many associated queries and too many JOIN associated databases will also lead to too slow queries (design defects or business requirements) ④ Server tuning and parameter setting (buffer / thr ...

Posted by markszy on Mon, 07 Mar 2022 22:53:31 +0100

Stack SQL optimization case: implicit conversion

The data stack is a cloud native one-stop data center PaaS. We have an interesting open source project on github and gitee: FlinkX , FlinkX is a unified data synchronization tool for batch flow based on Flink. It can collect both static data and real-time changing data. It is a data synchronization engine integrating global, heterogeneous and b ...

Posted by monkuar on Mon, 07 Mar 2022 19:42:08 +0100

Use CentOS + finalshell + node JS + MySQL + git + gitee + Tomcat + nginx + domain name resolution to build a simple website tutorial

catalogue 1, Purchase and installation of server 2, Download of required software 2.1. Final shell download and installation 2.2,Node.js 2.3,MySQL 2.4,JDK 2.5,Tomcat 2.6,Nginx 2.7,Git 3, Node JS installation and configuration 4, Installation and configuration of Git and gitee 5, Tomcat installation and configuration 6, Installation ...

Posted by SnaD on Mon, 07 Mar 2022 17:34:50 +0100

mysql data backup and recovery

mysql data backup I summary The main purpose of backup is disaster recovery. Backup can also test applications, rollback data modification, query historical data, audit, etc. II Importance of data backup In the production environment, the security of data is very important, and any loss of data may have serious consequences. III Causes of ...

Posted by Eddyon on Mon, 07 Mar 2022 15:24:03 +0100

yum installation and Navicat connection of MySQL installation

MySQL installation using yum   MariaDB is installed by default in CentOS7, which is a branch of MySQL. However, MySQL should be installed in the system for the sake of needs, and MariaDB can be directly overwritten after installation. 1. Download and install the official MySQL} Yum Repository [root@BrianZhu /]# wget -i -c http://dev.mysql.co ...

Posted by RonDahl on Mon, 07 Mar 2022 06:53:49 +0100