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  Oracle Advanced query

  This chapter will learn how to use the collection operator, which is used to combine the rows returned by two or more queries using the TRANSLATE function 1, and to use the set operator to explain that UNION ALL returns all rows retrieved by each query, including duplicate rows UN

  2022-06-01 10:37:37 Views: 218
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  Build a highly available MongoDB cluster (shard)

  For basic MongoDB, please refer to: https://blog.51cto.com/kaliarch/2044423MongoDB (replica set). Please refer to: https://blog.51cto.com/k.

  2022-06-01 10:37:07 Views: 227
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  Allow remote hosts to access the database

  1. Preface when you first install mysql, when you look at the user table. You can see the following hosts and users. When we connect in, we use root@localhost. But if you log in with other Host and user, there is no way to log in successfully.

  2022-06-01 10:37:01 Views: 206
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  Silently install Oracle and create database 11G R2

  Oracle.install.responseFileVersion=/oracle/install/rspfmt_dbinstall_response_schema_v11_2_0oracle.in

  2022-06-01 10:37:00 Views: 212
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  Oracle 11g single instance call 11.2.0.3.4 P14275605 PSU

  1. Close all instanceSQL > shutdown immediate 2. Close all listeners $[oracle@ora_11g test01] $lsnrctl stop3. Close all background sqlplus [

  2022-06-01 10:37:00 Views: 273
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  Change the self-incrementing id of the postgresql data table

  Change the self-increment id of the postgresql data table first check the index name of the self-increment ID that needs to change the table: use the command:\ d you_table_name as shown in the following figure, server_server_id_seq in the Default column

  2022-06-01 10:36:54 Views: 255
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  Win10 installation oracle12c encountered INS-20802

  Possible reason: the listener did not start, reconfigure the listener. Solution: find the installed Net Manager from the start directory and enter the listener directory under the net configuration. Add the address under LISTENER: host: computer username port: 1521 save on exit

  2022-06-01 10:36:54 Views: 267
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  Mha Construction and matters needing attention

  Introduction: MHA (Master High Availability) is currently a relatively mature solution in the high availability of MySQL, which is developed by youshimaton (now working for Facebook) of DeNA Company in Japan.

  2022-06-01 10:36:53 Views: 290
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  Apply PMDK to modify WAL operation to fit persistent memory

  Apply PMDK to modify the WAL operation to adapt to persistent memory these patches can read and write WAL logs stored on persistent memory PMEM by using PMDK. PMEM is the next generation storage medium, which has a series of characteristics: fast, byte addressing and non-volatile. Pgben

  2022-06-01 10:36:53 Views: 209
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  Detailed explanation of MongoDB replication set

  What is a replication set? Replication sets are additional replicas of data, the process of synchronizing data across multiple servers, providing redundancy and increasing data availability, through which hardware failures and interrupted services can be restored. The principle of master-slave synchronization of replication sets is similar to that of mysql, where the master node is recorded in its

  2022-06-01 10:36:50 Views: 294
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  Show index selection rate of MySQL

  What does each field information in show index from tbl_name\ G; represent? DROP TABLE IF EXISTS t create TABLE t (an int not null,b va

  2022-06-01 10:36:49 Views: 230
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  Linux WEB Server Building-MySql

  Using source code installation, you can add some parameters according to the actual production environment to improve mysql performance mysql official website https://www.mysql.com/ this article uses version 5.1 dedicated installation instructions, the later version such as 5.5 installation method will be somewhat different, in the company

  2022-06-01 10:36:49 Views: 293
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  Redis common commands (2) list keys, unordered set keys

  # the basic element type of the list key is string, and sort lpush key value1 value2 according to the insertion order. # insert data lpush name dai liu wangrpush key on the left side of the list

  2022-06-01 10:36:49 Views: 278
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  Introduction of mybatis and Environment Construction

  First, the reasons for not using pure jdbc, that is, disadvantages. 1. The database understands that creating when in use and releasing when not in use will frequently open and close links to the database, resulting in a waste of database resources and affecting the performance of the database. Imagine: use the connection pool of the database. 2. Hard-code the sql statement to

  2022-06-01 10:36:38 Views: 253
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  Imp for learning data migration

  Query database language and character set select userenv ('language') from dual;select * from nls_database_parameters # server select * f

  2022-06-01 10:36:38 Views: 285
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  Reinstall EM process after Oracle installation is complete

  Starting Oracle11G emctl start dbconsole reports the following error Environment variable ORACLE_UNQNAME not defined. Please set O

  2022-06-01 10:36:37 Views: 302
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  Solve the problem of exploding "sqlplus: command not found" when executing script

  As shown in the question, an error occurred while executing the script on the Linux server where oracle is installed: [oracle@hp-db test] $. / getSysdate.sh./getSysdate.sh: line 10:

  2022-06-01 10:36:23 Views: 223
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  Write down an error in MySQL master-slave replication

  This master-slave replication often makes mistakes, and so am I. the last reason is that there is a problem with the configuration file of the slave library, which I have solved, and today I have made another mistake, as shown in the figure: so the solution is to skip the wrong transaction. Before MySQL5.6, simply execute: mysql > set glob

  2022-06-01 10:36:23 Views: 281
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  Xtrabackup backup restore single library / table

  It is convenient to restore a single database / table using mysqldump logical backups. However, when the amount of data is large, it takes too long to restore the logical backup. Choosing a physical backup at this time can greatly shorten the time involved. Using xtrabackup for

  2022-06-01 10:36:22 Views: 278
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  Detailed explanation of address book items

  / * * @ author Mr.Deng* @ since 2016-5-14 * @ version 1.0 * use notepad to open it easy to read * Welcome to correct mistakes and write down your opinions * / Project description: users can log in to manage their own.

  2022-06-01 10:36:22 Views: 229