Database Administrator

(Linux parameters) Open the/etc/my. cnf file and modify the following settings. If not, add it manually. When adjusting the settings, please do your best, which depends on the configuration of your server, especially the memory size. The following

The MySQL database was installed on the Linux system a few days ago, and the following error message is displayed when you press the MySQL command: Can't connect to local MySQL server through socket '/var/lib/mysql. sock' The following error

At the end of this article, I found a fatal problem with ZRM for MySQL. As far as I understand and test it, it overwrites data recovery, for example, assume that a database server has two databases test1 and test2. You have backed up these two

MySQL dual-host hot backup is often used in Linux Server lvs load balancing and dual-host hot backup applications. The installation and configuration process is as follows: 1. Install MySQL # Cp

-- Alert. log has the following warning logs: Errors in file/u01/app/Oracle/admin/ESUITE/bdump/esuite_rvwr_23296.trc:ORA-19809: limit exceeded for recovery filesORA-19804: cannot reclaim 18055168 bytes disk space from 85899345920 limit -- View the

Today on the server df next, a look, var directory has been 98%, clear some log files and backup files found that mysql below a lot of files similar to mysql-bin.000001, if Google says it's a log, it's useless. Database operation logs Mysql-bin.000

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You can choose from two solutions: 1. Use the database upgrade assistant (dbua) upgrade utility provided by oracle to directly upgrade 9i database to 10 Gb. 2. Create a 10 Gb database and use the import/export (imp/exp) utility of oracle to migrate

Concurrency and Data Reading When multiple sessions simultaneously access (operate) the same data, unexpected results may occur, including: -Dirty read -- Dirty reads-Non-repeatable reads-Phantom read-Phantom reads1. Dirty read refers to when a

I. Using a MySQL database: 1. view the database structure: View the databases on the current server: SHOWDATABASES statement: Used to list the databases contained in the current MySQL server. After initialization, the MySQL server creates three

(I) INSERT large data volume (1) Replace a single row with multi-row insert: insert into t values (),(),(),... (2) load data infile... into table t (3) Write a temporary table and INSERT... SELECT (4) cancel the index and constraints, and

I have recently studied how to solve the IO competition problem if the storage level cannot be optimized. Finally, I thought of asynchronous IO. My redo disk write speed has reached the maximum value, no matter how I adjust the redo size and number

I. MySQL replication: MySQL replication introduction: The ddl and dml operations of the master database on the master server are uploaded to the slaves server through binary logs, and these log files are re-executed on the master server, in this way,

Create an Oracle DBlink1. You must use the database administrator to grant the otcts user the permission to create dblink. Grant create database link User_nameWith admin option; Commit;   2. Create a DBLinkCREATE PUBLIC DATABASE LINK

A developer said that there was a problem when using postgres's extended row-to-column application. The example is as follows: For more information about the extension package, see: I. EnvironmentOS: CentOS 6.3DB: PostgreSQL 9.3.0 Ii.

After hive-0.11.0 came out, I learned that row_number was encapsulated. It is a great happiness for me who do not know java! Don't hesitate to discard 0.8.0! The specific upgrade steps are as follows: 1. Disable the processes currently being

When I clone a database, the following error occurs at the source option: Solution: run $ Oracle_HOME/root again. sh to solve the problem. because the root is executed during database installation. sh. It is suspected that the re-execution of root

Configure the database environment, goldengate users, and install goldengate. For more information, see steps 1-4.Configuration required for Oracle-Oracle one-way replication using the Data Pump: -- Here I only configure to synchronize the test3

MySQL 5.5 Command Line Client cannot be opened (disappears in a flash) Solution Solution: 1. Find the bin directory path under the mysql installation directory. 2. Open cmd, enter the path to the bin directory, and enter mysql-u root-p. Problem

1. Install redis -------------------------------------------------------------------------------- Home: http://redis.io/: Http://download.redis.io/download the latest source package (current latest stable version 2.6.16)# Wget