Category:Database

  • Mysql uses profile to analyze SQL overhead

    Time:2019-3-15

    Mysql uses profile to analyze SQL overhead 1. Check the version information of the current database before using it. The low version can not be used. Show version (); or show variables like’% version%’ 2. View profiling show variables like ‘%profil%’ ; result: +————————+——-+ | Variable_name | Value | +————————+——-+ | have_profiling | YES | […]

  • Great, Ant Gold Clothes! Creating China’s own database Ocean Base (Part 2)

    Time:2019-3-15

    Technological Achievements: Epoch-making Distributed Databases Through the continuous online core business, Ant Golden Clothes helped Ocean Base overcome the most difficult application of self-developed basic software products. Ocean Base is not only developed, but also used. It is honed in the production system. As a benchmark enterprise of Internet finance, Ant Golden Clothes also realized […]

  • Redis string

    Time:2019-3-15

    Redis string The string of Redis is the type corresponding to SET and GET operations, which is the most commonly used type in Redis. 0x00 dynamic string SDS Redis internal string representation, instead of using C language string directly, has been modified to some extent. The performance of the modified string in memory management and […]

  • Nodejs Connect 12 Collections of Database Examples

    Time:2019-3-15

    Cassandra Module: cassandra-driver Installation $ npm install cassandra-driver Example var cassandra = require(‘cassandra-driver’) var client = new cassandra.Client({ contactPoints: [‘localhost’] }) client.execute(‘select key from system.local’, function (err, result) { if (err) throw err console.log(result.rows[0]) }) Couchbase Module: couchnode Installation $ npm install couchbase Example var couchbase = require(‘couchbase’) var bucket = (new couchbase.Cluster(‘http://localhost:8091’)).openBucket(‘bucketName’) // add […]

  • SQL Server changes user-defined database roles

    Time:2019-3-15

    Notes for changing user-defined database roles To run this command, one or more of the following privileges or memberships are required: Have ALTER privileges for rolesHave ALTER ANY ROLE privileges on databasesMembership with db_securityadmin fixed database roleIn addition, to change membership in a fixed database role, you need to: Membership with db_owner fixed database roleThe […]

  • Using Nuxt.js to Build Server-side Rendering (SSR) Applications Quickly

    Time:2019-3-15

    Install nuxt.js Nuxt.js officially takes advantage of two methods to initialize the project. One is to use Nuxt.js team scaffolding tool create-nuxt-app, the other is to configure freely according to their own needs.Scaffolding is suitable for beginners and knows the background framework of nodejs; according to their own needs, they need to know how to […]

  • The usage of mongodb + PHP

    Time:2019-3-14

    Mognodb database connection default format $m = new Mongo(); // The default port 27017 is used here to connect to the local machine. Of course, the remote host such as 192.168.0.4:27017 can also be connected. If the port is 27017, the port can be omitted. Standard connection $m = new Mongo(“mongodb://${username}:${password}@localhost”); Example: $m = new […]

  • MySql forgot the login password of root, how to operate it?

    Time:2019-3-14

    MySql forgot the login password of root, how to operate it? Warning: First, make sure that the server is in a secure state, that is, no one can connect to the MySQL database at will. Because during the period of resetting MySQL’s root password, the MySQL database was completely password-free. In this state, other users […]

  • Partition Knowledge Points

    Time:2019-3-14

    benefit Partition level performs data management operations such as data loading, index creation and reconstruction, or backup and recovery, rather than the entire table. Improving query performance Shorten maintenance time Partition independent operation Improve availability Code logic does not change classification Select partitions automatically according to the partition key, and support insertion, update and deletion […]

  • Add B_tree and hash | Write a Redis by yourself

    Time:2019-3-14

    Recently, I learned Redis and was interested in its internal structure. In order to further understand its operation principle, I plan to write a redis in C++ by myself. This is the first time that I have made a wheel, so I’ll commemorate the ___________ Source GitHub links, the project now implements client-server links and […]

  • Simple Practice APP “Every Reader”

    Time:2019-3-14

    It’s not difficult or a lot of knowledge to use. Mainly to consolidate knowledge, understand the project structure and so on. Of course, if you like this app, you can also install it on your mobile phone and read it every day. Github Transport=>ReadingHabit Download address=>Click on me to download APK There is something wrong […]

  • Delete user-defined database roles from SQL Server

    Time:2019-3-14

    Notes for deleting user-defined database roles The role with a secure object cannot be deleted from the database. To delete database roles that have secure objects, you must first transfer ownership of these secure objects or delete them from the database. The role with members cannot be deleted from the database. To delete roles that […]