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  [3 minutes daily technical practical information | interview questions + answers | Mysql (1)

  1. What are the three paradigms of the database? The first paradigm emphasizes the atomicity of columns, that is, each column of a database table is an indivisible atomic data item. The second paradigm: requires that the attributes of the entity are completely dependent on the primary keyword. Full dependency means that there can be no attributes that depend on only part of the primary keyword. The first

  2022-06-01 22:36:06 Views: 238
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  Oracle conversion Postgres

  1. First of all, you need to be familiar with the SQL of Oracle and PostgreSQL. The more detailed you understand it, the more advantageous it is. This article helps readers quickly understand what is the difference between these two types of SQL. If you need to migrate Oracle to PG because of ACS/pg, then

  2022-06-01 22:36:05 Views: 295
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  The SQL log is growing rapidly, how to query the corresponding operation sql content?

  / * query which log records will cause such a sharp change. * / select @ @ SPID,Operation,dblog. [Transaction Name], [Transaction ID], AllocUnitNa

  2022-06-01 22:36:05 Views: 274
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  MongoDB sets Replication Sets

  There are two types of MongoDB highly available: Master-Slave master-slave replication: you only need to add the-master parameter when one service starts, and the other service adds-slave and-source parameters to achieve synchronization. Mo

  2022-06-01 22:36:02 Views: 293
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  SQL Syntax hint SQL Prompt Operation tutorial-Control Code recommendation

  SQL Prompt is a practical SQL grammar prompt tool. It automatically retrieves according to the object name, syntax and code snippet of the database, and provides users with appropriate code choices. Automatic script settings make the code easy to read-especially useful when developers are not familiar with scripts. SQL

  2022-06-01 22:35:53 Views: 280
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  Responsible for database backup, realize incremental backup from Monday to Saturday and full backup on Sunday

  1. Full backup and incremental backup of mysql. Enable the logbin log function of mysql. Add the following code to the / etc/my.cnf file: [mysqld] log-bin = "/ home/mysql/logbin.log" b

  2022-06-01 22:35:52 Views: 206
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  HBase-1.0.1 Learning Notes (2) HBase data Model

  Lu Chunli's work notes, who said that programmers should not have literary style? For an introduction to NoSQL Database, see: the main categories of http://www.nosql-database.org/ include: a, Wide Column Store /

  2022-06-01 22:35:46 Views: 252
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  Mysql's subquery

  For the subquery after exists, exists only cares about whether there is one or not, and returns Boolean type # case: query the name of the department with employees SELECT department_nameFROM departments dWHERE EXIS

  2022-06-01 22:35:16 Views: 297
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  MySQL stored procedure

  Blog outline: 1. What is a stored procedure? 2. What are the advantages of stored procedures? 3. Examples of custom stored procedures 4, stored procedures of while loops 5, stored procedures with if judgment 6, stored procedures with case 7, outputting stored procedures to global environment variables 8, and other information about

  2022-06-01 22:35:15 Views: 286
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  MySQL view

  What is a view? A virtual table, just like the real one. The view contains a series of row and column data with names. Views are derived from one or more tables, and we can manipulate them through insert,update,delete. When the data seen through the view is repaired

  2022-06-01 22:35:15 Views: 297
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  New features of integrated development environment PL/SQL Developer v13.0

  Allround Automations is a privately held company based in the Netherlands. Founded in 1989, the company is the world's leading service provider in Oracle development tools. Among them, product PL/SQL Developer is an integrated development

  2022-06-01 22:35:07 Views: 208
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  Restart the listening report TNS-01201

  Find the corresponding listener.ora file RAC generally check whether the parameter configuration of this file is incorrect under GRID_HOME/network/admin/ or ORACLE_HOME/network/admin, and modify it accordingly.

  2022-06-01 22:35:06 Views: 261
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  Centos 7.5 installation and configuration MongoDB 4.0.4

  MongoDB is a database based on distributed file storage. Written in C++ language. Designed to provide scalable high-performance data storage solutions for WEB applications. MongoDB is a product between relational database and non-relational database, which is irrelevant.

  2022-06-01 22:35:00 Views: 301
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  Complete construction of LNMP environment + WordPress deployment from scratch

  0. There will be a lot of content, but the following content is a complete reappearance of yourself in the process of learning to build a LNMP environment, so it is of great reference value! Here is an example of a CentOS 6.5 operating system installed in minimized mode (Minimal) to demonstrate the LNMP ring

  2022-06-01 22:34:33 Views: 301
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  Switch over from dataguard rac to stand-alone

  After http://snowhill.blog.51cto.com/339421/1923591, is built, check the parameter fal_server,fal_client,log by switch over:1.

  2022-06-01 22:34:03 Views: 288
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  MySQL indexes, views, stored procedures

  I. the index in the conceptual database of the index is similar to the catalogue in the book. In a book, you can quickly find the catalogue in the required information book without reading the whole book. The catalogue in the book is a list of words, which indicates that the page number database containing each word is indexed in the database, and the index makes it unnecessary for the database program to

  2022-06-01 22:34:03 Views: 204
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  Mysql disk space explodes

  After going to work today, I suddenly found that the disk space of mysql from the library was suddenly full. After some inspection, I found that ibtmp1 took up a lot of space, which was almost 300g. According to the query, ibtmp1 file is a new feature of MySQL5.7, and MySQL5.7 uses

  2022-06-01 22:33:48 Views: 296
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  SpringCloud implements real-time database expansion in sub-database and sub-table mode.

  1. Project structure 1, project structure 2, module naming shard-common-entity: common code block shard-open-inte: open interface management shard-eureka-7001:

  2022-06-01 22:33:48 Views: 272
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  Learning log-hbase optimization summary

  The optimization of HBase is summarized: pre-partitioning, column families, batch read and write, merge, link pool. For details, see below: 1. Design of the table (the first three most important) 1.1 Pre-Creating Regions by default, it is created automatically when the HBase table is created

  2022-06-01 22:33:47 Views: 253
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  Thoughts on upgrading the minor version of MySQL 5.7.25 active and standby Architecture In-Place

  First, the description of missing scan found that MySQL has low-risk vulnerabilities, write their own solutions, do their own tests, their own upgrades. Version: MySQL 5.7.25 to the latest version of MySQL 5.7.28. Architecture: master-slave architecture 2, upgrade process 1, download the latest version of database software My

  2022-06-01 22:33:47 Views: 242