With regard to MySQL master-slave mode, if we build it directly on this machine, it will not be possible to build it, only with the help of virtual machines, but sometimes we need to set up a master-slave cluster for some functional testing.At this point, we can try using docker. With docker's containerization technology, we only need to create ...
Posted on Sun, 01 Sep 2019 20:52:58 -0400 by sebnewyork
Chapter 1 ServletContext Objects
1.1 What is ServletContext
ServletContext: The context object of a servlet. The ServletContext object knows everything before and after the Servlet. This object has only on ...
Posted on Thu, 29 Aug 2019 23:47:32 -0400 by lilwing
Introduction to Spring Boot
Spring Boot is a new framework provided by the Pivotal team, designed to simplify the initial build and development of new Spring applications. The framework uses a specific way to configure, so that developers no lon ...
Posted on Thu, 29 Aug 2019 07:34:36 -0400 by kee1108
How keyBy specifies key
Whether streaming or batch processing, there is a keyBy(stream) and groupBy(batch) operation. So how do I specify key?
Some transformations (join, coGroup, keyBy, groupBy) require that a key be defined on a collection of elements. Other transformations (Reduce, GroupReduce, Aggregate, Windows) allow data being group ...
Posted on Thu, 29 Aug 2019 04:50:50 -0400 by pradeepknv
Introduction to Common Operators of MySQ(1). Arithmetic operators(2). Comparing Operators(3). Logic Operator(4). Bit Operator(5) Operator priority
Introduction to Common Operators of MySQL
Operators are symbols that tell MySQL to perform characteris ...
Posted on Thu, 29 Aug 2019 03:14:31 -0400 by elToro
The use of is null, is not null,!= in the sql query statement of mysql has no effect on the index, and does not scan the whole table because of the use of is null, is not null,!= in where condition.
mysql official document It has ...
Posted on Wed, 28 Aug 2019 07:21:48 -0400 by ashida123
mariadb installation and use
A database is simply a warehouse for storing data. By organizing and storing data according to a certain data structu ...
Posted on Wed, 28 Aug 2019 05:09:06 -0400 by mewright
I. Basic Part
1. What is a database?
What I learned before is that data must be permanently saved, such as user information registered by users, all in files, and files can only exist on one machine.
If we don't consider the efficiency of reading data from a file and assume that all components of our program run on a single machine, there's no ...
Posted on Wed, 28 Aug 2019 01:47:48 -0400 by baudday
7. MySQL Subdatabase Subtable
(1) Introduction to the concept of sub-database and sub-table
MySQL has two ways of splitting database tables: vertically and horizontally.Vertical splitting: Vertical splitting refers to splitting tables into different database tables by module (in principle, or without breaking the third paradigm), which is comm ...
Posted on Tue, 27 Aug 2019 14:12:43 -0400 by shiggins
Click above to learn java and choose Star Public Number
Heavy information, dry goods, first delivery
Broadly announced: Clock-in prize-winning activities are in progress. Come and join us, ...
Posted on Mon, 26 Aug 2019 12:20:07 -0400 by infini