Optimization of mysql-system status view-location problem, analysis of sql, index

The initial stage of system development pays attention to function realization, and data is relatively small. With the increase of data volume, performance problems will gradually become prominent. Query system status information show [sesison |global ] status; mysqladmin extended-status show st ...

Posted on Sun, 06 Oct 2019 07:41:37 -0700 by osusano

Fuzzy Query + Dynamic (Multiple Conditions) Query (ssm)

Fuzzy query and dynamic query are one of the necessary functions of some management classes. Just as we have done this function today, let's summarize it. I am in the framework of ssm, the environment configuration is omitted First of all, dao.xml is sql statement. <select id="fine" resultType=" ...

Posted on Sun, 06 Oct 2019 06:59:00 -0700 by haagen

java database completes additions, deletions and alterations

First, the origin of the problem When beginners start to do management system, they finish it in console, give the client, then input the specific operation, and the problem arises. As long as they close the eclipse data, it will disappear, which will cause great inconvenience. Then, we start to try ...

Posted on Sun, 06 Oct 2019 03:23:04 -0700 by www.phphub.com

Spring Boot Master-Slave Read-Write Separation

It encapsulates a read-write separated Starter, which can configure any number of data sources and use Hikari connection pool (other connection pools are not supported for the time being). GitHub: rw-separate-spring-boot-starter The code has been uploaded to the Maven Central Warehouse and can be used directly: <dependency> <groupI ...

Posted on Sat, 05 Oct 2019 08:20:25 -0700 by simonp

Python Road [Article 24]: Database Index

Database Index Introduction to Index Index, also known as "key" in mysql, is a data structure used by storage engines to quickly find records. Indexing is critical to good performance, especially when the amount of data in tables is increasing, the impact of indexing on performance becomes more and more important.   Index optimiza ...

Posted on Sat, 05 Oct 2019 03:17:31 -0700 by proctk

My.ini file can't be found in mysql root directory. Recreate my.ini

1. First of all, I opened the hidden file according to the Internet, or I could not find my.ini. 2, if method 1 finds... No need to look at 2. Accept reality if you don't find it. You need to create my.ini yourself and reconfigure it. (1) The administrator runs cmd on the premise that the mysql environm ...

Posted on Sat, 05 Oct 2019 03:14:06 -0700 by Alidad

Data Integrity

In order to ensure that the data in the initial drawing database can correctly reflect the real situation, some constraints on entity integrity of the data will be made in the table. For example, a student information must contain a student number (indispensable) Domain integrity Name 123 Type Limite ...

Posted on Fri, 04 Oct 2019 21:58:10 -0700 by shadow-x

Mysql Stored Procedures

stored procedure know In some programming languages, such as pascal, there is a concept called "process" and "function", such as sub. Java, Python, PHP in VB, no process, only function. Procedure: Several statements are encapsulated and executed when invoked. Function: A process with a return value (ps: Python function is bo ...

Posted on Fri, 04 Oct 2019 14:11:12 -0700 by gladius

Detailed description of JDBC query method execution process

Detailed description of JDBC query method execution process import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; interface IRowMapper{ void rowMapper(ResultSet resultSet); } public class Select { //Detailed description of JDBC query method execution process //Goal ...

Posted on Fri, 04 Oct 2019 02:56:50 -0700 by magicdanw

mysql distributed lock of deadly java synchronization series

problem (1) what is distributed lock? (2) why do we need distributed locks? (3) How does mysql implement distributed locks? (4) The advantages and disadvantages of mysql distributed lock? brief introduction With the increasing concurrency, the single-machine service will evolve to multi-node or micro-service sooner or later. At this time, synch ...

Posted on Fri, 04 Oct 2019 00:11:11 -0700 by fr600