Database Administrator

MySQL Databases can not only be joined between tables, but also can be joined by themselves. This function is quite comfortable. Let's take a look at how to make the table join itself in mysql.Create a table in MySQLCreate table d(Id int (10)

Because Red Hat enterprise linux 5 comes with a mysql, When you install a new mysql, an error is prompted, such:Error: Failed dependencies: MySQL conflicts with mysql-server-5.0.77-4.el5_4.2.i386 Rpm-qa | grep mysql can see the installed mysql.

1. Install MySQL using the following two files: MySQL-server-5.0.26-0.i386.rpm MySQL-client-5.0.26-0.i386.rpm For the http: // unzip Hat Enterprise Linux 3 RPM (x86) downloads item, find the "Server" and "Client programs" items and download the

Multiple Oracle databases physically stored in the network can be logically considered as a single large database. Users can access the data in the remote database through the network, the collaborative processing between servers is completely

1. Modify the/etc/my. cnf FileDefault-character-set = utf8[Mysqld]Datadir =/var/lib/mysqlSocket =/var/lib/mysql. sockUser = mysql# Default to using old password format for compatibility with mysql 3.x# Clients (those using the mysqlclient10

Bulk collect can be used to load the query results to collections at a time, instead of processing them one by one Using CURSOR. You can use bulk collect in select into, fetchinto, and returning into statements.Note that when bulk collect is used,

====================================== SRVCTL ================ ======================1. List all configured DatabasesSrvctl config database 2. display all services of the specified cluster DatabaseSrvctl config service-d GDTV 3. view the status of

By default, Oracle sqlplus cannot start the execution of analysis plans and statistics execution efficiency. To start the following functions, you only need to take a few steps: 1. log on to the system using the sysdba role of the sys user. 2:

The table exists clearly. The deletion times: the table or view does not exist ~! Row 3 has an error:ORA-00942: Table or view does not exist I finally figured out the reason because my table name is in lower case, but in upper case, this problem

The strace in Linux can help us track program system calls. LGWR is an important process in Oracle and is responsible for writing redo logs into online redo logs. Let's try to use strace to peat LGWR behavior. First, find the LGWR process Number:

The Linux server uses the system crontab to regularly execute Backup files and save the backup results by date to achieve the backup purpose. 1. Create the path to save the backup file/mysqldata # Mkdir/mysqldata 2. Create the/usr/sbin/bakmysql

The lpad function is an Oracle database function. the lpad function fills the string with the specified characters on the left. It can be understood from its literal meaning that l is short for left, pad is the meaning of fill, so lpad is the

During Oracle development, various forms of report presentation are often encountered. Some reports cannot be directly written using SQL statements, and must be implemented in concert with SQL, however, the report query speed is slow and is not

Every time the server administrator notifies that a file occupies too much hard disk space, it is estimated that the tablespace of the Oracle database has become larger. There is no way. You need to be aware of the number of tablespaces currently

How to handle HANG Databases 1. Generate systemstate dump:SQL> sqlplus-prelim/as sysdbaSQL> alter session set max_dump_file_size = unlimited;SQL> alter session set events 'immediate trace name systemstate level 10 ';Wait for some 30 secondsSQL>

When an expdp statement is executed today, the following error is returned: ORA-31626: job does not existORA-31633: unable to create master table "NEW. GWJOB"ORA-06512: at "SYS. DBMS_SYS_ERROR", line 95ORA-06512: at & quot; SYS. KUPV $ FT & quot;,

I. Principle of MySQL master-slave Replication What is mysql master-slave Replication Mysql supports several different forms of replication, such as single bidirectional, chained cascade, and asynchronous replication. During the replication process,

Create error table: Create sequence seq_error_log_id;Create table error_log (id number, unit_name varchar2 (30 ),Err_code varchar2 (100 ),Err_desc varchar2 (4000 ),Err_date date ); Automatically expand the partition package: Create or replace

MySQL installation methods include rpm and source code compilation and installation. This article will demonstrate installation without compilation.I. installation and configuration 1. Create a mysql user and decompress the mysql installation

11.1 view fra location SQL> show parameters db_recovery_file_dest NAME TYPE VALUE ----------------------------------------------------------------------------- Db_recovery_file_dest string Db_recovery_file_dest_size big integer 0 Select * from v $