Programmer Group

1.SpringBoot What is SpringBoot Spring Boot makes it easy to create stand-alone, production-grade Spring based Applications that you can "just run". We take an opinionated view of the Spring platform and third-party libraries so you can get started with minimum fuss. Most Spring Boot applications n ...

Level 1 Cache Mybatis supports caching, but by default without configuration, it only turns on the first level cache, which is relative to the same SqlSession.So when we invoke a Mapper method using the same SqlSession object with exactly the same parameters and SQL, we usually execute SQL only once ...

Table of contents structure of this article Scenario description Using code replication to solve the problem step by step Repetition problem Thinking about expanding problems Scenario description A product line is too laggy around January (end users 5W or so). When a customer manager feedback to ...

ElasticSearch aggregate filtering, similar to having in SQL Specific note: All content of the article is based on ElasticSerch version 5.5.3 background In real business scenarios, we encounter the need for aggregation filtering, which requires grouping, aggregation, and filtering through the results of aggregation. The ...

[SQL from bit by bit Analysis series articles] is a bit by bit summary in actual development, from the simplest SQL query to comprehensive analysis query When analyzing SQL, related operations in mybatis and Hibernate will also be analyzedClick to view details This section describes inserting data in ...

Preface As mentioned in the previous article How MyBatis builds configuration classes Yes, I also said that MyBatis is mainly divided into two phases in the running process, the first is building, the second is executing, so this article will take you to see how MyBatis goes from building to executing our first SQL statement.This part of the co ...

MyBatis part2 Article directory MyBatis part2 Many to one processing One to many processing Dynamic SQL IF chooose(when,otherwise) trim(where,set) Foreach Before knowing many to one and one to many, the feeling after learning is like learning the joint table query in MySQL statements (there ...

Author: ye Jinrong, co-founder of zhishutang, and co-founder of 3306pai community Preface What causes the util and iowait of disk I/O of online database server to keep soaring? 1. Problem description A friend Xiaoming's online database gave a serious alarm. The business side reported that writing data was blocked all the time. Many locks ro ...

1. About testing Recently oracle held a series of online sharing, one of the new features of 19c is automatic indexing. I tested it in docker and failed. [oracle@8aa96a41b58b ~]$ sqlplus / as sysdba SQL*Plus: Release 19.0.0.0.0 - Production on Thu Feb 20 09:44:52 2020 Version 19.3.0.0.0 SQL> EXEC DBMS_AUTO_INDEX.CONFIGURE('AUTO_INDEX_MODE ...

About the uniqueness of object naming in SQL Server database. For example, database objects such as tables, indexes, constraints, etc. sometimes, DBA s often need to create or rename objects when doing database maintenance. At this time, they will encounter a problem, the uniqueness of object naming. Although it's a small question, it's not cle ...