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I DDL – operating databases and tables 1. Query SHOW DATABASES; 2. Create Create database CREATE DATABASE Database name; Create database (judge, create if it does not exist) CREATE DATABASE IF NOT EXISTS Database name; 3. Delete Delete database DROP DATABASE Database name; Delete the database (judge, delete if it exists) ...

The title is an error, a minority error, which may be related to postgresql or citus. However, this error can only exist in one place on the network. Story background The wrong background is used benchmarksql The tool tests the TPCC performance of citus. Because citus is a distributed plug-in of PG, which can turn multiple stand-alone PG node ...

I believe that through the analysis, reading and understanding of the articles in front of Xiaobian, readers can have a certain content understanding. Let's have a more in-depth understanding of JDBC tools together with Xiaobian! catalogue Encapsulation of JDBC tool class Why encapsulate tool classes? Encapsulated tool class (in the too ...

1. Introduction to NoSQL development 1.1 technology development NoSQL: mainly used to solve performance related problems. 1. Monomer Era However, with the rapid increase in the amount of data, the application server will have CPU and memory pressure, and the database service will have IO pressure. 2. Solve CPU and memory pressure ...

1. Technology use jsp+Servlet+jdbc idea 2020.3 Mysql 5.8 tomcat 8.5 sqlYog 8.7 2. Prepare tools jdbc Driver Download: For mysql drivers above 5.8, a special upgrade driver is required Portal: mysql-connector-java-8.0.13.jar/.keep · xuge/java - Gitee.com 3. Frame construction 3.1 establish student information table CREATE TABLE stude ...

PostgreSQL is the most open source database like oracle. We can compare Oracle and learn its architecture, which is easier to understand. The main structure of PostgreSQL is as follows: 1. Storage structure PG data storage structure is divided into logical storage structure and physical storage structure. Among them: logical storage structur ...

Welcome to the MySQL technical articles shared by the great SQL community. If you have any questions or want to learn, you can leave a message in the comment area below. After seeing it, you will answer itDifferent parameters added to lsof will produce different results. Be careful of "stepping on the pit".1. Background:It was acciden ...

catalogue 1, Compile mysql-5.7 1. Unzip file 2. Installation dependent environment 3. Create a user 4. cmake parsing 5. make compile install 2, Modify profile 1. Change primary group 2. Enter configuration file 3. Modify the primary group of the profile 4. Setting environment variables 5. Initialize database 6. Add launcher 7. Ope ...

Variable, process control, cursor Personal blog: www.xiaobeigua.icu 1. Variables In the stored procedures and functions of MySQL database, variables can be used to store the intermediate result data of query or calculation, or output the final result data. In MySQL database, variables are divided into ...

Transaction It exists in both SQL server and Mysql It refers to the smallest unit to complete an application processing, which is composed of one or more statements operating on the database. If all operations are successful before submitting a failure, all operations will be cancelled and restored to the previous state. 1. Cases where transac ...