• Dbask Q & a session 4


    Link descriptionIntroduction Recently, our dbask applet has been newly associated with the public numbers in the data fields such as the beauty of operation and maintenance, high-end storage knowledge, yisengaji, operation and maintenance coffee bar. Welcome to read and share. Quiz collection Next, we will share the problems and diagnosis summary sorted out in this […]

  • PostgreSQL database is even hotter than this summer!


    What is PostgreSQL? PostgreSQL is a powerful enterprise level relational database management system built by JD cloud based on the open-source PostgreSQL version 10.6. PostgreSQL is known as “the most advanced open source database available in the world”. In the past 20 years of rapid development, the database has been widely used in GIS scenarios. […]

  • Source compilation and installation of PostgreSQL 11.4


    1 environment Operating system: CentOS 7.6 (CAT / etc / RedHat release) PostgreSQL version: 11.4 (because 12 is still in beta) 2 preparations 2.1 install GCC editor [[email protected] postgresql-11.4]# gcc –version gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-36) Copyright © 2015 Free Software Foundation, Inc. This program is free software; please refer to the copyright […]

  • EMQ x auth & ACL based on PostgreSQL


    Before reading this tutorial, assume that you have a simple knowledge of mqtt, mqtt 5, and EMQ X. Emqx auth PgSQL checks theusernameandpasswordWhether the information stored in the PostgreSQL database specified by the user is consistent to realize the access control to the terminal. Its functional logic is as follows: This article assumes that PostgreSQL […]

  • Billion level storage challenge! Take a look, WeChat advertising, WeChat payment, small procedures are used in the storage system is how to carry? !


    | lead language 1 billion level, is the order of magnitude of WeChat users. Behind this huge number, is “take a look”, “WeChat advertising”, “WeChat payment”, “small program” and other businesses on the database 1 billion level of read and write demand. So, how is FeatureKV a powerful storage system born in this scenario? Background: […]

  • Mo tianlun document open test, three good gifts you take


    Event detailsMok documents are organized by technical experts and uploaded to the database related solutions. Currently support PDF, PPT, WORD, TXT format files, users can browse all documents online free, but also through the ink value to download to the local. Now open beta, invite you to become a technical expert and upload documents, three […]

  • Dbask Q & a session 6


    Introduction Recently, we have newly connected DB preparation room in dbask applet and added more than 60 technical experts. We look forward to more experts in database field and authors of public account joining motianlun to create an open, mutual and professional database technology community. Quiz collection Next, we will share the problems and diagnosis […]

  • Blocklang 0.4.0 released


    Blocklang source code: https://github.com/blocklang https://gitee.com/blocklang Blocklang demo website: https://blocklang.com Like Maven in Java, npmjs in JavaScript, cargo in rust and other dependency management tools, block Lang version 0.4.0 also introduces dependency management functions. The block Lang project depends on the component warehouse registered in the component market. In the component market, we call it “component […]

  • Usage of with in PostgreSQL


    Usage of with statement With query defines an auxiliary statement in a complex query (which can be understood as a temporary table defined in a query). This feature is often used in the application scenario of complex query or recursive query. 1. In complex query statements [email protected]:5432=>with t as mydb-> (select generate_series(1, 3)) mydb-> select […]

  • A brief introduction to Ruby on rails’ support for PostgreSQL array types


    I’m very glad to announce that rails 4.0 now supports PostgreSQL array types. You can easily create array type fields in migration through: array = > true. You can also add other options (length, default, etc.) when creating array type fields.   create_table :table_with_arrays do |t| t.integer :int_array, :array => true # integer[] t.integer :int_array, […]

  • Settings of auto add fields for each database (mysql, PostgreSQL, Oracle, MSSQL)


    In the process of database design, we usually set the ID field in the database table to auto increment. Here are the commonData dictionary tableFor example, it shows how to set the auto increment field under each database. MySQL Mysql database only needs to be added on the target fieldAUTO_INCREMENT, and set for tableAUTO_INCREMENT=x。x: number […]

  • Instance code of database backup (PostgreSQL, MySQL) in docker environment


    PostgreSQL backup / recovery 1. backup DATE=`date +%Y%m%d-%H%M` Back? Data = xxapp data – ${date}. Out? The name of the backup file is set here. The adding date is to prevent duplication. Docker exec PG DB PG? Dump – u Postgres > ${back? Data}? PG DB is the docker name of the database 2. recovery […]