Database Administrator

1. Check whether Mysql is installed in Linux. [Root @ localhost zhoulinghong] # rpm-qa | grep MySQL MySQL-server-community-5.1.22-0.rhel4 Already installed. 2. Install mysql (rpm) in Linux) [Root @ localhost zhoulinghong] # rpm-ivh

The Linux server crashed for three days, and it was a naughty Mysql. After the IDC restarted the server, it was found that Mysql failed to start. the restart of the server and Mysql repeatedly failed, this is really a time of the world, people do

// Title: MySQL character set (my summary) // By dx_andy // Time: 2007.8.27 evening // Test environment: win32 MySQL 5.0.45 // Cause: Garbled MySQL Since the launch of MySQL 4.1, the garbled code problem for Chinese people has also aroused the risk

MySQL supports unidirectional and asynchronous replication. During the replication process, a Linux server acts as the master server, and one or more other servers act as slave servers. The master server writes updates to the binary log file and

Test environment: Oracle 9.0.4 in Linux 1. log on with an oracle userIf you want to install it again, you 'd better back up the data first. The script includes the user's login script, the script for automatic database startup and shutdown, and the

OS: Windows 2003 Server Oracle9.2.0.1 Symptom: When you compile PL/SQL functions with DEBUG, a crash occurs. The details are as follows: The following is a function: SQL> create or replace function A2 (arg_bh User_Tables.table_name % type)2 return

An earlier version of mysql server has been installed on the Linux server in use. When the rpm package is used for installation, a version conflict is prompted and the installation cannot proceed. The solution is as follows: 1. First, find all the

Recently, the company's servers are always faulty. Sometimes the access speed is too slow to handle. I am just getting started with Linux, but I can't find the problem. I am so bored. First, I want to modify the mysql configuration file to check

Reconfigure MySQL. Remove service, mysqld-nt-remove, success. There are other commands on the Internet, and the operation fails. Re-Configure. The error 1045 is displayed. Run the MySQL Command, set password for 'root' @ 'localhost' = PASSWORD

MySQL also designed a native driver called mysqlnd for PHP6, which is a MySQL database driver using the PHP open source protocol (PHP license) and avoids any possible copyright problems, so PHP developers can use it with confidence. Mysqlnd becomes

1. Obtain the Oracle 10g Installation File 2. Configure the installation environment for Debian 2.1 configure sysctl. conf # Vi/etc/sysctl. conf Add the following content to the end of the file: Kernel. shmall = 2097152 Kernel. shmmax =

MySQL has built the Replication function since version 3.23. We can configure it to master-slave mode or master-master mode. The method is very simple. Here we will record the configuration of the master-master. Here I test mysql 5.1.31. One is

Considerations for importing and exporting Oracle databases1. When Oracle exp exports the dmp file, the storage clause defined by the table structure is exported by default, and the compress parameter is Y by default, after repeated exp and imp

Take scott. emp as an example. Based on the position (MGR) number, find all information about the position number.Create TYPE first: equivalent to the TYPE of each row of record, which can be understood as scott. emp % rowtype1.CREATE or replace

We recommend that you change the undo_retention parameter when installing the Oracle software. We recommend that you change the default value of 900 to 10800 seconds, that is, 3 hours; alter system set undo_retention = 10800 scope = both; A part of

When you use the delete obsolete command to delete obsolete backup files, if the following error occurs (RMAN-06207 & RMAN-06208), you need to use the CROSSCHECK command to resolve it: RMAN-06207: WARNING: 2 objects cocould not be deleted for DISK

MongoDB replica Set Primary-Secondary switchover Experiment 1. Create a directory for the replica Section [Root @ bakdbserver ~] # Mkdir-p/var/lib/mongo/dbs/node1 [Root @ bakdbserver ~] # Mkdir-p/var/lib/mongo/dbs/node2 [Root @ bakdbserver ~] #

A few days ago, my colleague sent an SQL statement saying that the update operation was very slow. I checked that the data volume was not large. Check the execution plan and find that the execution path is incorrect. Why is the execution path

ERROR: ORA-28002: the password will expire within 7 days In Oracle 11G, the default password expiration time is 180 days. If your database does not have such high security requirements You can change it to unlimited. SQL> set wrap off;SQL> set

1. view the database lock and diagnose the source and type of the lock:Select object_id, session_id, locked_mode from v $ locked_object;Or run the following command:Select B. owner, B. object_name, l. session_id, l. locked_modeFrom v $ locked_object