Database Administrator

1. Enable rsync from the Database Server Vi/etc/rsyncd. conf Edit rsync Configuration /Usr/bin/rsync -- daemon Start rsync 2. Stop the crontab of the log Collection Server /Etc/init. d/cron stop 3. Stop the primary database rsync Ps aux | grep rsync

When using expdp to export data in Oracle, sometimes an error occurs. In this case, some records are generated in dba_datapump_jobs. You can see the following command: Select * from dba_datapump_jobs; Now we can see the corresponding JOB_NAME.

There is a stored procedure, which already has four dblinks, but due to business needs, a few more needs to be added. When it is added to the fifth, the system suddenly throws an error: ora-02020 too relational database links in use. Consulting

When Oracle sqlplus is used in linux, the arrow keys do not move the cursor left or right by default, and the commands are up and down. Therefore, if you want to execute the commands that have already been executed, you should try again or use the

It is often necessary for Oracle databases to automatically execute scripts, back up databases, refine data, or optimize database performance, including re-indexing, etc, in this case, a function dbms_job.submit is used to process the Oracle timer

Limit and offset are usually used together with order. Indexes are helpful for sorting and comparison, If no index is available, a large number of files are sorted. Therefore, you must add an index to the order by column. If: Select * from

Learn how Active Data Guard performs real-time queries, applies archived logs, converts physical backup databases to Snapshot Backup databases, and provides a series of improvement measures for the infrastructure, this makes your investment in the

Use RMAN> show all;The following shows the RMAN configuration parameters: Configure retention policy to redundancy 1; # defaultConfigure backup optimization off; # defaultConfigure default device type to disk; # defaultConfigure controlfile

C: \> sqlplus SQL * Plus: Release 9.2.0.1.0-Production on Saturday September 29 15:08:34 2007 Copyright (c) 1982,200 2, Oracle Corporation. All rights reserved. Enter the User name: sys as sysdbaEnter the password: Connect:Oracle9i Enterprise

Checkpoint Process: triggers the checkpoint, synchronizes data on the memory hard disk, writes the system change number to the control file and data file, and triggers the dbwr process to write the cached data to the database. The lgwr process is

It mainly solves the problem of Chinese garbled characters. The following command is unified into gb2312. If you want to use gbk, replace gb2312 with gbk. Enter the command line mode, If the MySQL database has been installed, you can use the

Remote connection error: TNS-: no listenerCause: the listener is not started.Solution:Reconfigure listener. ora in $ Oracle_HOME/network/admin.The following standard files LISTENER =(DESCRIPTION_LIST =(DESCRIPTION =(ADDRESS = (PROTOCOL = IPC) (KEY =

Article 1: First, you must have a table! Create table example ( ID Number (4) not null primary key, Name varchar (25 ), Phone varchar (10 ), Address varchar (50) );   Then, you need a custom sequence Create sequence emp_sequence Increment by 1 --

After installing MySQL in Ubuntu, we usually need to set the default Character Set of the database. # First look at the default character set in mysql. # Log on to mysql Mysql-h localhost-u root-p # View character-related attributes Show variables

1. Create a tablespace table SQL> CREATE TABLESPACE table name; Example: SQL> create tablespace mytablespace; 2. Create a user (in the tablespace table created above) SQL> CREATE user username identified by password default tablespace table name

MySQL uses the memory pool structure. It is quite simple to understand this structure, but it is hard to understand the allocation process in my_alloc.c./*Data structures for mysys/my_alloc.c (root memory allocator)*/# Ifndef _ my_alloc_h# Define _

A source code process for MySQL to receive and execute connection commandsCall Sequence of functions from top to

Implement MySQL ReplicationAfter MySQL 3.23.15, MySQL provides the database replication function to synchronize two databases in real time, enhance the stability of MySQL databases, and implement Cluster at the database layer of enterprise-level

Because the server suddenly loses power, the database cannot be started after the machine is restarted.Database Version Oracle10201, OS RedHat 5.4No database archive and no backup [oracle @ hunan02 ~] $ Sqlplus/nologSQL * Plus: Release

Tail-f/var/log/messages/u01/app/Oracle/product/10.2.0/db_1/OPatch/opatch/U01/app/oracle/product/10.2.0/crs_1/OPatch/opatchORA_CRS_HOME =/u01/app/oracle/product/10.2.0/crs_1ORACLE_HOME =/u01/app/oracle/product/10.2.0/db_1 add