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  Mongodb comes with monitoring mongostat numerical description

  Insert: number of inserts in a second query: number of queries in a second update: number of updates in a second delete: number of deletions in a second getmore: getmore operation of the cursor when querying command:

  2022-06-01 17:10:48 Views: 248
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  Variable table and temporary table in SQL

  1. Variable table: declare @ SDT datetime,@EDT datetime-- define the start and end time of execution set @ SDT=getdate ()-- define variable table declare @ t table (

  2022-06-01 17:10:47 Views: 210
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  Setting up MongoDB installation environment

  The default port number 27017_id of Mongodb is a globally unique value. Do not assign a value to this column. It is unique by default. If you assign a value and include _ id:2 with two columns, it will report a conflict and cannot insert [root@HE4 ~] # tar xvf mongodb.

  2022-06-01 17:10:47 Views: 224
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  Elaborate on the three paradigms of database

  1NF: fields can not be divided; for example: table 1, user ID name area 1 Xiaoming Guangzhou City, Guangdong Province 2 Xiaohong Nanjing City, Jiangsu Province, the fields can be divided into: provinces and cities as follows: table 2, user ID name province city 1 Xiaoming Guangdong City 2 Xiaohong Nanjing City, Jiangsu Province Table 1 does not conform to the first paradigm, Table 2 accords with

  2022-06-01 17:10:33 Views: 234
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  Oracle Data Guard broker encounters bug at the scene, flash ~

  Recently, we set up a disaster recovery environment at the customer site and found that we encountered BUG. If we give up broker, we can still realize that ADG,Oracle can not achieve dual hosts, but MySQL can do so. Record it on the official website. OERR: ORA-16

  2022-06-01 17:10:33 Views: 284
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  Index design specification

  (indexes can increase query efficiency, but also reduce the efficiency of inserts and updates) (therefore, each innodb table must have a primary key) because innodb is because the index organizes the table, if the primary key is updated frequently, it means that the logical data stored in the data will change frequently, which will inevitably lead to large

  2022-06-01 17:10:33 Views: 223
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  Waiting for table metadata lock

  [problem description]: in the master-slave environment of Mysql5.6, the fields added to the master library can never be added, and no value has been returned. [troubleshooting analysis]: 1. There is no problem with execution in the test environment, and it will be returned soon. Because the amount of data is not large, it is only about 10w (online is also about 10w).

  2022-06-01 17:10:23 Views: 210
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  Extrabackup

  1.centos7 installation (centos6 can download the corresponding version officially) wget https://www.percona.com/downloads/XtraBackup/Percona-XtraBacku

  2022-06-01 17:09:53 Views: 282
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  Windowns2012 installs domain control and open source mrbs conference room management system ldap

  The installation principle of Win2012 domain control: the user needs to enter the user name and password to log in to the mrbs system. Mrbs gets the password and the user verifies to the domain control server, and the authentication is successful to let the user log in to the mrbs system operation: the preliminary preparation work 1. You need to configure static ip2. Repair

  2022-06-01 17:09:53 Views: 253
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  Installation of MongoDB online yum source and detailed explanation of basic commands

  Introduction to MongoDB 1) Mongodb is a non-relational database, and data records are stored in document form (key-value pairs), that is, bson format 2) there is no longer the concept of "row", and its operation is mainly based on two concepts: collection.

  2022-06-01 17:09:50 Views: 236
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  Use vmware workstation 10 to simulate the installation of RAC 11g R2

  Here only describes the installation environment, the specific installation content can directly download the attachment to view the VM version: VMWare-workstations 10OS version: OracleLinux-R6-U5-Server-x86_64-dvd_6.5.is

  2022-06-01 17:09:49 Views: 296
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  Implement the solution to the error of root.sh Times

  Oracle Overview Oracle Database, also known as Oracle RDBMS, or Oracle for short. It is a relational database management system of Oracle. It is a leading product in the field of database. We can say that Oracle data

  2022-06-01 17:09:48 Views: 236
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  Permission setting of SQL Server and data backup and restore

  SQL Server is a relational database management system developed by Microsoft Company. It has the advantages of easy to use, good scalability and high integration of related software. it can span from laptops running Microsoft Windows 98 to transportation.

  2022-06-01 17:09:47 Views: 280
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  Complete implementation of cascade replication of database cluster

  Note before the experiment: if you want to enable cascading replication, you need to enable the following configuration on the slave server; the role of [mysqld] log_binlog_slave_updateslog_slave_updates: because the default comes from the master server

  2022-06-01 17:09:32 Views: 273
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  Processing when NULL is included in Oracle's where condition in/not in

  We often use the in condition when writing SQL. If in contains non-null values, there is nothing special, but if the values in in contain null values (for example, in is followed by a subquery, and the result returned by the subquery has a NULL value), what will Oracle do?

  2022-06-01 17:09:32 Views: 264
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  At least one of monitoring servers is not reachable from this script.

  Secondary_check_script= / usr/local/bin/masterha_secondary_check-s 172.17.0.2-s 172.17.0.3-s 172.1

  2022-06-01 17:09:32 Views: 207
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  Postgresql High availability tool pha4pgsql

  Postgresql has many highly available tools, of which pha4pgsql is a very good software, worth using, the following is the official link address, which contains detailed information for reference: https://github.com/ChenHuajun/pha4

  2022-06-01 17:09:31 Views: 293
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  Oracle prompt error message ORA-28001: the password has expired

  Prompt error message ORA-28001: the password has expired is investigated due to the new features of Oracle 11G. The default password expiration limit for Oracle 11G when creating users is 180 days, if it exceeds 1.

  2022-06-01 17:09:31 Views: 232
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  Control the recovery of files with backup

  Use backup to control the recovery of files. The control file does not contain data files, but there are alter database backup controlfile to'd:\ control.ctl';create tablespa in the online log.

  2022-06-01 17:09:22 Views: 253
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  Pt-archiver data deletion, use of migration tools

  1. Database connection parameter description A character encoding D library F from file read option L load data local file P port Ssocket file a database b if it is true, disable the index m plug-in module used by the SQL_LOG_BINh database address I query

  2022-06-01 17:09:19 Views: 217