How can small teams make good use of JuiceFS
When I was in ENJOY in the early years, I was already using JuiceFS and accompanied the four small companies I worked for all the way. This has become an indispensable infrastructure for me and a real help for the small team I have served Take advantage of the nearest Essay solicitation activities , continue to expand my small team series and i ...
Posted by Cazrin on Fri, 01 Apr 2022 12:06:36 +0300
ambari add and install hive service
On the non master node, install hive meta storage.
Example: as shown in the figure, if hdp-3 is selected, install it on hdp-3.
Then click next and hive. Do not configure it first. After the database is installed and configured, configure hive on this page
At this time, we first switch to xshell for operation, install mysql database on ...
Posted by starmsa on Fri, 01 Apr 2022 11:16:36 +0300
A murder case caused by deleting elements in the list in the loop
cause
Recently, I received a request (false) to remove the objects younger than 18 years old from the member object in a list. Otherwise, there will be problems after the display.
After you get the demand, you can write it quickly. The logic is also very clear, and the approximate code is as follows:
void removeMember(List<Member> list ...
Posted by libertyct on Fri, 01 Apr 2022 09:38:42 +0300
MySQL index transaction
catalogue
MySQL index transaction
1. Index
1.1 concept
1.2 function
1.3 use
1.4 cases
2. Services
2.1 concept
2.2 use
3. Summary of key contents
MySQL index transaction
1. Index
1.1 concept
An index is a special file that contains reference pointers to all records in a data table. You can create indexes on one or more columns i ...
Posted by bdamod1 on Fri, 01 Apr 2022 09:18:44 +0300
mysql database sql exercise summary day 1 (fuzzy query, sum() and count(), grouping statistics, grouping result condition query)
😁 Teddy: (official account: Chicken storehouse story remit)
⏰ Time: 11:31:46, March 18, 2021
☁️ Weather: Sunny
preface
sql must be the most familiar thing for everyone, and it is also something we often deal with. Maybe you think the first part is super simple, so you should be a big man and admire it. "Reviewing the old ...
Posted by zenag on Fri, 01 Apr 2022 01:56:56 +0300
mysql5.7.33 Error deleting ibdata file to retrieve data
1. Scene description:
Many times the data is inaccessible because the MySQL database cannot be started, but the applied data is usually not lost, only other files such as the system tablespace are damaged, or MySQL bug s are encountered. If there is no backup at this time, many people think the data is lost, but in fact most of the time the da ...
Posted by fingerprn on Thu, 31 Mar 2022 20:33:53 +0300
python data analysis - use of MYSQL variables
1, Variable introduction
1. MYSQL variables can be divided into two categories: system variables and user variables (also known as user-defined variables). 2. System variables are divided into global variables and session variables. User variables are divided into local variables and user variables. 3. Scope: that is, the effective range, when ...
Posted by itbegary on Thu, 31 Mar 2022 19:00:44 +0300
node connection MongoDB and common operation records
Personal interface for the back end of the whole stack project
preparation
I think it is necessary to understand some concepts in advance
Install mongoDB Library
npm i mongodb
Install a mongodb Library
Connect database
// If the database address is not changed, it is the default address
const url = "mongodb://localhost:27017";
...
Posted by goodrunb on Thu, 31 Mar 2022 11:06:18 +0300
Syntax, engine, transaction, optimization, index, user management, backup, design protocol and JDBC connection pool of MySql basic overall textbook
MySql
Java EE: enterprise development, Web oriented
Front page: display dataBackground: connection point, link frontDatabase: save data
Database should learn operating system, data structure and algorithm, discrete data, mathematical circuit, architecture, compilation principle and practical experience well
Why: learn everything beca ...
Posted by HektoR on Thu, 31 Mar 2022 09:45:26 +0300
MySql notes-03 data manipulation language (DML)
Data manipulation language (DML)
1. Concept
Data manipulation language (DML), through which users can realize basic operations on the database. For example, query, insert, delete and modify the data in the table. However, there are three main forms of DML: data insertion, modification and deletion
2. Insert data
Insert statement ...
Posted by Gomesh on Thu, 31 Mar 2022 00:08:34 +0300