Database Administrator

This article explains how to use left join, cross join, and IDENTITY value retrieval to Improve the Performance of SQL Server-based applications or improve their scalability. What you will encounter: SQL queries in applications cannot respond in

MSSQLServer instances can be installed on a maximum of 16 instances in version 2000, just as if 16 SQLSERVER instances are installed on one server. Of course, there is no need to install 16 instances on one physical machine, however, during

Since Oracle 11g, Oracle databases provide Alert logs in XML and traditional text formats.The new log location is determined by the Automatic Diagnostic Repository (ADR. You can use the new initialization parameter DIAGNOSTIC_DEST to control the

After Oracle is installed in Linux, If you restart Linux, Oracle will not start automatically. You can manually call the dbstart command to start it. However, this seems complicated. We can configure the Oracle Automatic startup script and then use

Since Oracle10g, Oracle has greatly enhanced the OEM tools and provided a full display of EM tools on the server side. In Oracle10g, the client can call powerful EM tools without installing any Oracle client tools. On the Server side, run the

Before Oracle 11gR2, we usually use start with and connect by to recursively display the tree structure. See the following script. Select lpad ('', 2 * level-1,'') | ename, empno, mgrFrom empWhere empno is not nullConnect by prior empno = mgrStart

An Oracle trigger is a special type of stored procedure, which is different from the stored procedure. A trigger is executed when an event is triggered. trigger events can be divided into three categories: DML events, DDL events, and database events,

Oracle variant table In the Oracle database, the variant table is the table currently modified by the DML statement. For triggrt (trigger) on the database, the variant table is the table defined by the trigger on it. It must be clear that the SQL

Spool is easy to use, but it is not familiar with the set command in formatting data, so I found it online. In this note: SQL> set colsep ''; //-domain output Separator SQL> set newp none // sets the number of pages for the queried data. If

Oracle 10 Gb partition tables do not support automated management. Generally, you must manually create and delete partitions. Today, we have a script for automated table space management. This script consists of three parts: sys_ConfigTable. SQL,

-- SQL reads all fields in a specified data tableDeclare @ TableName nvarchar (250) -- Name of the data table in the current operationSet @ TableName = 'hzfa '-- specify the name of the data table to be queried (please change it to the name of the

ORA-01031insufficient privileges Gpasswd-d Oracle dba -- remove oracle from the dba group View oracle attributes Uid = 500 (oracle) gid = 500 (oinstall) groups = 500 (oinstall) [Oracle @ oracle10g ~] $ Rman target/Recovery Manager: Release 10.2.0.1.0

In the Oracle RAC environment under VMware, multi-path images of ocr or votingdisk are not enough for shared storage or need to be added to a new shared disk, we can add shared storage through the command line under VMware, and then append these new

After installing Oracle 11 GB in Linux, use sqlplus with the following garbled code. [Oracle @ localhost ~] $ Rlwrap sqlplus/as sysdba SQL * Plus: Release 11.2.0.1.0 Production on Wed Jan 23 15:25:02 2013 Copyright (c) 1982,200 9, Oracle. All rights

Error about Oracle ORA-01555 snapshot old First understand under what circumstances Oracle will generate a ORA-01555 error: Assume that there is a 60 million-Row Table testdb. It is estimated that it will take two hours to scan the entire table once.

Non-current online Log File fault recovery 1. ORA-00313 error when starting the database. ORA-00313: open failed for members of log group 1 of thread 1ORA-00312: online log 1 thread 1: '/home/Oracle/oradata/s1/redo01.log' 2. view the v $ log

Media restoration is used when data files are lost or damaged, or control files are lost. Media restoration restores the restored data file to the current data file. It can also restore the abnormal offline data files without having time to make

1. Configure the environment;MGM: 192.168.0.31NDBD1: 192.168.0.32NDBD2: 192168.0.33SQL1: 192.168.0.34SQL2: 192.168.0.30  2. Software Installation(1) Management node MGMFirst, create a configuration file for the management node at an appropriate

To adjust indexes, we can use the index monitoring feature provided by Oracle to track whether indexes are used. Although this feature does not provide the index usage frequency, it is still one of our reference methods. However, the index is also

Oracle online redo log files record all changes to the database (DML, DDL, or structural changes made to the data by the administrator ), it is used for accidental deletion or downtime to use log files for data recovery to ensure data integrity.