Opening the slow query log enables MySQL to record the statements that are queried for more than the specified time. Only by locating and analyzing the bottleneck of performance, can we better optimize the performance of the database system.
2, Parameter description
Slow query log slow query on status
Slow q ...
Posted by aesthetics1 on Thu, 19 Mar 2020 11:14:18 -0700
Before using PyMySQL, we need to make sure PyMySQL is installed.
PyMySQL download address: https://github.com/PyMySQL/PyMySQL.
If it is not already installed, we can use the following command to install the latest version of PyMySQL: $ pip install PyMySQL
If your system does not support the pip command ...
Posted by ganlal on Thu, 19 Mar 2020 09:10:11 -0700
Some sql runtime is time-consuming, consumes system resources, and cannot be further optimized, and each time the data is obtained, it does not change much.
Then the information obtained by this sql statement will be cached for the next execution
This saves system resources very much
View query cache size
mysql> selec ...
Posted by centered effect on Wed, 18 Mar 2020 09:19:40 -0700
– preparation before database operation
– create database
– create database python_test_1 charset=utf8;
– using databases
– use python_test_1;
– students table
– create table students(
– id int unsigned primary key auto_increment not null,
– name varchar(20) default ",
– age tinyint ...
Posted by ksteuber on Wed, 18 Mar 2020 09:11:11 -0700
JDBC for transaction management
There are four characteristics of a transaction:Atomicity: refers to that the operations contained in a transaction are regarded as a logical unitConsistency: the database is in a consistent state before and after the startIsolation: multiple transactions modified to the database are isolated from each otherThe i ...
Posted by Mark Baker on Wed, 18 Mar 2020 08:30:03 -0700
In the previous section, we used a variety of authentication methods of CAS to complete the login authentication in a variety of ways, that is, we mainly used a variety of authentication schemes encapsulated by CAS for us, which can basically meet our multiple needs of authentication. If you still don't know a lot about the multiple authenticat ...
Posted by BlueMeteor on Wed, 18 Mar 2020 06:15:25 -0700
Hello, what follows is not exclusive content about MAC, basically related to Java environment and basic technology.So this tutorial is common to both linux systems and macOS, so don't worry.
In the previous post, we found Docker convenient after installing it.Now let's install Mysql, which is often used in development.
MySQL is the most popula ...
Posted by redhair on Tue, 17 Mar 2020 18:51:18 -0700
1, Environment deployment
1. Build docker environment
yum -y install docker
2. Install docker compose
curl -L https://github.com/docker/compose/releases/download/1.23.2/docker-compose-`uname -s`-`uname -m` -o /usr/bin/docker-compose
chmod +x /usr/bin/docker-compose
3. Create project directory
mkdir -p /data/jms
4. Download the doc ...
Posted by efron on Tue, 17 Mar 2020 11:02:24 -0700
Recently, we have encountered the need for keyword query on large text. The effect to be achieved is that when a user enters a word or a word, all the contents containing the word or a word should be searched. It's the same as MySQL's LIKE query.
In this scenario, the first thing I think about is to directly use MySQL storage, and then query, w ...
Posted by idnoble on Tue, 17 Mar 2020 08:19:00 -0700
The missing are back! Since I have been crawling, I have encountered many pits, so I will give a general report first
1. Access to all enterprises in the country
2. Supplement enterprise information through enterprise inspection
3. Direct employment of reptile boss to obtain company and position i ...
Posted by huzefahusain on Tue, 17 Mar 2020 03:15:31 -0700