1, Database operation
1) Select and create database syntax:
use database name
The rule of the use command is to switch if the corresponding database exists, and create if it does not exist
2) Deletion of database
3) View databases with permissions
show dbs or show databases
Note: when you use the use com ...
Posted on Sun, 05 Dec 2021 02:17:05 -0500 by SwiftlyTilting
mongoDb replica set
It mainly provides two functions
1. When data is written to the Primary node, copy the data to another replica node
2. When the primary node fails, a new replacement node is automatically selected
Typical replica set structure
A typical replication set consists of three or more nodes with voting rights. ...
Posted on Wed, 01 Dec 2021 06:28:12 -0500 by skippy111
1. Common shell
namecommandCreate tablecreate 'table name', 'column cluster name 1', 'column cluster name 2'get dataget 'table name', 'row key', 'column cluster name: column name'Add dataput 'table name', 'row key', 'column cluster name: column name', 'value'View all tableslistView table structuredesc 'table name'Delete columndelete 'table ...
Posted on Wed, 01 Dec 2021 04:31:53 -0500 by modcar
As usual, the figure above first. In the last NOSQL article, a big man said that he would learn all the databases of the first figure. Today, he specially posted only one small figure. One is enough!
Mongo does not mean Mango, but comes from the word Humongous.
MongoDB is a NoSQL database based on distributed file storage. W ...
Posted on Mon, 29 Nov 2021 08:24:23 -0500 by cs-web
[tcaplus DB knowledge base] Introduction to tcaplus DB local index
Tcallusdb supports two types of indexes: local indexes and global indexes.
Local index: an index based on the tcallusdb primary key field. It is created with the table when it is being created.Global index: an index based on the first level fields (including ...
Posted on Fri, 19 Nov 2021 04:29:02 -0500 by phpshift
CentOS 7.9 MongoDB installation and use
1, Software download and installation
Note: CentOS versions include RedHat / CentOS 7.0 and RedHat / CentOS 7.2 s390x. It is recommended to download software installation packages consistent with the CPU architecture of the operating system to ensure compatibility and high performance. Enter arch ...
Posted on Thu, 11 Nov 2021 21:19:57 -0500 by invinate
1, BackgroundRecently, after looking at the knowledge of redis, I found that a new data type Stream has been generated in redis5, which is somewhat similar to the design of kafka and can be used as a simple message queue.2, Characteristics of Stream type in redisIt is persistent and can ensure no data loss.Support message multicast and packet c ...
Posted on Mon, 08 Nov 2021 23:11:07 -0500 by said_r3000