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background Of course, the background of snowflake algorithm is the demand for unique ID generation in the high concurrency environment of twitter. Thanks to the awesome technology inside twitter, snowflake algorithm has been spread and widely used. It has at least the following characteristics: It can meet the requirement of no duplicate ID i ...

Tuning system System administrators can adjust various device settings based on a variety of use case workloads to optimize system performance. The tuned daemon uses a tuning profile that reflects the requirements of a specific workload to apply tuning in both static and dynamic ways. Configuring the static tuning tuned daemon applies the ...

Learning content: Learn Java Web (Day40) 1. Database Connection Pool 2. java uses CommonsEmail to send e-mail 1. Database Connection Pool (1) Download dependency packages for DBCP, C3P0, DRUID, Hikaricp connection pools DBCP: http://commons.apache.org/dbcp/ C3P0: http://sourceforge.net/projects/c3p0/ DRUID: https://druid.apache.org (2) DB ...

6. Services Transaction is to execute a group of SQL statements in the same batch. ACID principle: Atomicity All operations in the whole transaction are either completed or not completed. It is impossible to stagnate in an intermediate link. If an error occurs during the execution of a transaction, it will be rolled back to the state before ...

1. View functions: Request Object------------- request: 1,HttpRequest.body:) Request original data 2,HttpRequest.path:) A string representing the requested path component (without domain name)           3,HttpRequest.method　　           4,HttpRequest.GET           5,HttpRequest.POST           6,HttpRequest.FILES 7,HttpResquest.user:) An AUTH_U ...

My physical standby failed to start and terminate MRP due to ora 01274 problem.This problem is very simple to handle, but Baidu almost took me to the pit after searching an article, so I wrote down the standard steps of MOS for your friends to refer to. This DG environment was built two weeks ago and needs to be officially switched today.Befor ...

There is a deep doubt about laravel-admin's picture upload mechanism. Deleting avatar pictures on the user information page will cause an error. It was 1.4 at that time, and later updated 1.5 found that the delete button disappeared directly. If you use image normally in the form during the process of use, the slight ...

There is a deep doubt about laravel-admin's picture upload mechanism. Deleting avatar pictures on the user information page will cause an error. It was 1.4 at that time, and later updated 1.5 found that the delete button disappeared directly. If you use image normally in the form during the process of use, the slight ...

First import the corresponding jar package for Spring-hibernate Then prepare the file for the database connectionHibernate.propertiesAlsoJdbc.properties Hibernate.propertiesFile: Configure the hibernate dialect and automatic table building hibernate.dialect=org.hibernate.dialect.H2Dialect hibernate.hbm2ddl.auto=create Jdbc.propertiesFi ...

jqweui I don't know how many people have used it. I often use it to develop webapps Its select component is more often used, but this time I need to get the selected items data from the database instead of writing the page dead After thinking about it for a while, I finally came up with a method, which is also effecti ...