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  Installation steps of Oracle database

  Take oracle 11g as an example, double-click the oracle installation file to enter the installation interface, check the installation environment to continue, ignore the uncheck box to accept the security update, click next to select the system type here directly according to the actual needs, and the next step is to select the software installation location and database text.

  2022-06-01 16:01:04 Views: 208
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  ORACLE DataGuard active / standby handoff

  There is a disk problem in the primary database, which leads to the downtime of the primary database. Because the archive has not yet been applied, the standby database cannot be transferred to the primary database. First, check the current information of the secondary database: SQL > select * from vested version and BANNER-

  2022-06-01 16:01:03 Views: 240
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  Changing the Oracle database password causes the vcenter service to fail to start

  Background introduction: an enterprise uses a Windows2008R2 physical server to install vCenter Server 5.5 and Oracle 11g databases in an enterprise production environment, and VC uses a system account to connect to the Oracle database. At the beginning of installation

  2022-06-01 16:00:42 Views: 234
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  Delete a column from a table

  Delete column alter table sdrop constraint age_cons-- need to delete the constraint alter table sdrop column age before deleting the column

  2022-06-01 16:00:42 Views: 243
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  What is the RDB persistence of redis

  One of the obvious advantages of Redis over other cache products such as Memcache is that Redis not only supports simple key-value type data, but also provides storage of data structures such as list,set,zset,hash.

  2022-06-01 16:00:34 Views: 279
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  How to optimize the memory of redis

  1. Special coding: since Redis 2.2, many data types can be optimized for storage space by special coding. Among them, Hash, List and Sets composed of Integer can all optimize the storage structure in this way to reduce the footprint.

  2022-06-01 16:00:31 Views: 215
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  The expiration mechanism of Redis

  In this article, before we briefly explain the expiration mechanism of Redis, let's throw out a question. We know that many servers often use redis as a cache, and a lot of data is temporarily cached, which may not be used for a long time after use (such as storing sessio temporarily.

  2022-06-01 16:00:31 Views: 282
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  Oracle11g username password expires in 180 days

  When there is a password expiration problem, the processing method is as follows: 1: log in to the console to verify, and the JDBC test that comes with weblogic can verify database connectivity. At the same time, the application log should show an error that the password of ORA-28002 expires. 2: you can also log in to the database

  2022-06-01 16:00:30 Views: 236
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  Two kinds of persistence of redis

  1. Preface Redis is a kind of advanced key-value database. It is similar to memcached, except that data can be persisted and supports a wide range of data types. There are strings, linked lists, sets and ordered collections. Support for computing the union, intersection and complement of collections on the server side

  2022-06-01 16:00:24 Views: 263
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  Introduction and use of Lock in Redis

  In fact, it is not appropriate to modify data with multi-thread. after all, the redis server is single-threaded, and all commands are executed serially, but when the client sends commands concurrently, it leads to some problems in the arrangement of serial commands and the time difference in the network, which leads to data inconsistency. Although this article is an addition and subtraction of numbers, but in order to say

  2022-06-01 16:00:21 Views: 236
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  Oracle syntax

  1. Basic syntax: SELECT * [column name [[AS] alias], column name 2.] FROM table name [[AS] alias]; 2. Use | | to connect: strings in Oracle are in single quotation marks. Example: SELECT 'name:' | | e

  2022-06-01 16:00:21 Views: 288
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  DataGuard repository archive log automatic deletion configuration

  1. If there is no backup mechanism, if you want to delete the repository archive automatically, you need to use the quick recovery area (FRA) to check the location of the current repository archive: SQL > show parameter log_archive_dest_1NAME TYP

  2022-06-01 16:00:20 Views: 261
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  The usage of Memcached delete command and flush_all command

  Memcached sets the variable key how to delete or clear, the use of the delete command and flush_all command. 1 basic syntax of the delete command delete key 2

  2022-06-01 16:00:11 Views: 206
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  HBASE secondary index

  HBASE implements secondary index scenarios based on coprocessor as follows: store UC_TWEETS table, ROWKEY design: folderId_dayId_siteId_docId, export has the following requirements: according to campaignID guide

  2022-06-01 16:00:11 Views: 254
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  5: use GTID for replication

  Server 192.168.1.1 (master) 192.168.1.2 (slave) synchronizes the server, which is required only if the server is already replicating but is not using gtid. For new servers, proceed to step 5. On each server

  2022-06-01 16:00:11 Views: 237
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  Mysql database changes user password and user authorization

  Query user, password 1, select host,user,password from mysql.user; change password 2, update mysql.user set password=password ("op

  2022-06-01 16:00:10 Views: 280
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  Expiration handling Mechanism of redis

  This paper gives a brief overview of the expiration mechanism of redis, so that we can have a basic understanding. There is a function of setting time expiration in Redis, that is, you can set an expiration time for values stored in the redis database. As a cached database, this is very practical. Such as us.

  2022-06-01 16:00:10 Views: 237
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  What is redis cluster brain fissure? How to solve it?

  What is redis's clustered brain fissure? The cluster brain fissure of redis means that due to network problems, redis master nodes are in different network zones from redis slave nodes and sentinel clusters. At this time, because sentinel clusters cannot

  2022-06-01 16:00:10 Views: 268
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  MyFlash rollback mysql binlog

  Introduction: MyFlash is a tool for rolling back DML operations developed and maintained by the Technical Engineering Department of Meituan Dianping Company. The tool completes the rollback operation by parsing the v4 version of binlog. Compared with the existing rollback tools, it adds more filtering options to make rollback easier. Installation:

  2022-06-01 16:00:10 Views: 276
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  Postgresql Learning Notes (5) backup and recovery

  Postgresql Learning Notes (5) backup and recovery 1. Backup tools: pg_dump and pg_dumpallpg_dump can back up a specified databasepg_dumpall can back up all database data and

  2022-06-01 16:00:09 Views: 257