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  The difference between Phantom Reading and unrepeatable Reading in Mysql

  What is the difference between phantom reading and unrepeatable reading in Mysql? This problem may be often seen in our daily study or work. Through this question, I hope you can understand the difference between fantasy reading and unrepeatable reading. Non-repeatable: under the same conditions, the value of the read data occurs when we read it again.

  2022-06-01 17:15:27 Views: 294
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  Oracle 11g manual cold standby

  Check whether the database is in non-archive mode and close database shutdown immediate backup control files and data files (no backup log files, it is recommended to back up together) [oracle@enmoedu1 PROD] $lltotal 201

  2022-06-01 17:15:20 Views: 241
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  Mysql database setting password-free login

  The specific method is as follows: first, we want to stop the MySQL service with the following command: service mysql stop, then find [mysqld] in the / etc/my.cnf configuration file, plus configuration: skip-grant-tables for example

  2022-06-01 17:15:20 Views: 230
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  Powershell connects to multiple servers to execute SQL scripts

  $query = "select @ @ servername" $csvFilePath = "c:\ Scripts\ queryresults.csv" $instanceNameList = get-

  2022-06-01 17:15:20 Views: 280
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  Https station building experiment

  The ip of my linux host is 172.16.29.2 and the system is centos7.2. The operation content of using centos6 may be different, mainly because there are two, one is a database, and the database used by centos7 is mariadb,6 using m

  2022-06-01 17:15:20 Views: 257
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  The method of creating High-level connections in MySQL

  1. Using table aliases SQL allows aliases for table names in addition to column names and calculated fields. There are two main reasons for doing so: shortening the SQL statement and allowing the same table to be used multiple times in a single SELECT statement. Mysql > SELECT cust_na

  2022-06-01 17:15:16 Views: 253
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  Troubleshooting process of oracle Library Server on the one-Card vip recharge consumption Line

  The picture above is the general framework of the oracle system. Today, suddenly all the terminal POS machines of the company cannot be consumed by card, and the finance room cannot recharge. A lot of phone calls came over. The first reaction was that there was something wrong with the database. Log in to the database server. Sure enough, after sqlplus was connected, it kept prompting for input.

  2022-06-01 17:15:16 Views: 232
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  The method of viewing the version of Mysql database

  View Mysql database version 1, use terminal 1. Parameter is-V (uppercase) or-- version usage: d:\ mysql\ bin > mysql-V or D:\ mysql\ bin > mysql-- version disadvantage

  2022-06-01 17:15:16 Views: 255
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  What's the difference between InnoDB and MyISAM?

  MySQL InnoDB and MyISAM difference 1, transactions and foreign keys InnoDB has transactions, support four transaction isolation levels, rollback, crash repair capabilities and multi-version concurrent transaction security, including ACID. If a large amount of INSER needs to be performed in the application

  2022-06-01 17:15:16 Views: 214
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  Why optimize SQL? How many methods are there for SQL optimization?

  Several methods of SQL optimization: (1) to optimize the query, we should try to avoid full table scanning; (2) to avoid judging the null value of the field in the where clause; (3) to avoid using the! = or < > operator in the where clause as far as possible; 4. "in" and "not I"

  2022-06-01 17:15:15 Views: 278
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  Restrict IP access to oracle databases on specified machines

  The function of forbidding the designated IP host from accessing the database can be achieved by using the sqlnet.ora file on the database server, which is of great help to improve the security of the database. At the same time, this technology provides an effective means for us to manage and restrict database access control. The following is

  2022-06-01 17:15:15 Views: 240
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  How to create tables in MySQL Database

  For the complete steps of creating tables in MySQL database, first start the MySQL service, then open the MySQL database visualization tool, then connect to the MySQL database, then create a new database and set the character set to "UTF-8", and finally create a new table and set the fields to complete the database table creation.

  2022-06-01 17:15:00 Views: 289
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  Installation and configuration of centos

  When you first install CentOs, there are a few more things you need to do to make better use of the operating system. Shutting down selinuxselinux is really powerful, but it's too complicated, and it's above root, and root can't break through its limits. So

  2022-06-01 17:15:00 Views: 296
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  The solution of self-increasing ID of MySQL to reach the upper limit

  What if MySQL self-adding ID runs out? There are many types of self-increasing ID in MySQL. Each self-increasing ID sets an initial value, and then increases according to a certain step. As long as the byte length is defined, there will be an upper limit. If the upper limit is added again, a primary key conflict error will be reported.

  2022-06-01 17:15:00 Views: 300
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  The method of inserting tens of millions of data into mysql Database

  How does mysql implement circular insertion of tens of millions of levels of data? 1. Table creation: CREATE TABLE `mysql_ genarate` (`id` int (11) NOT NULL AUTO_INCREMENT, `uui

  2022-06-01 17:15:00 Views: 285
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  Find out the real culprit of MySQL disk consumption

  Find out the real background of MySQL disk consumption Part1: write in front of you when a single table with 1 billion data is placed in front of you, what will you face? Part2: background introduction: in order to improve the utilization of database resources, in an example, the premise of ensuring business efficiency without affecting each other

  2022-06-01 17:14:47 Views: 250
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  Oracle series: (25) Index

  What is an index [Index] (1) is a mechanism for quickly querying the contents of a table, similar to the contents of the Xinhua Dictionary (2) used on some / some fields in the table, but when stored, why should the index be used outside the table (1) accelerate the query speed of the Oracle server through pointers (2)

  2022-06-01 17:14:39 Views: 256
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  Mongdb installation and use

  1. Download address: https://www.mongodb.com/dr/fastdl.mongodb.org/win32/mongodb-win32-x86_64-2008plus-ssl-3.2.7-s

  2022-06-01 17:14:33 Views: 240
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  Windows SQL Server 2017 AlwaysOn AG automatic initialization test report

  Directory technical background prerequisites to create an availability group with automatic seed settings to view database synchronization progress temporarily prevent the primary copy from setting more database seeds to the secondary copy stop the automatic seed setting of a secondary copy on an existing availability group enable the automatic seed of a secondary copy on an existing availability group

  2022-06-01 17:14:33 Views: 233
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  Data backup and recovery of Oracle topic 17

  1. An overview of data backup and recovery A, the necessity of backup and recovery due to various software and hardware failures of the computer system, user misoperation and some malicious destruction are difficult to avoid, so this affects the correctness of the data, and even causes data loss, the serious consequences of server crash. So make frequent backups

  2022-06-01 17:14:05 Views: 229