Database Administrator

Software environment: 1. Windows 2000 + Oracle 8.1.7 2. ORACLE installation path: C: \ ORACLE Implementation Method: 1. Choose "start"> "Settings"> "Control Panel"> "Administrative Tools"> "services" to stop all Oracle services. 2. Start-> Program->

SHMMAX Available physical memory Defines the maximum allowable size of one shared memory segment. the SHMMAX setting shoshould be large enough to hold the entire SGA in one shared memory segment. A low setting can cause creation of multiple shared

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

When mysql 5.0 is displayed in Chinese, it becomes? No. However, it may be displayed normally in phpmyadmin. What is displayed on the webpage? . The gb2312 is used. If it is changed to UTF-8, it will not work.Add a statement to the

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

Install# Groupadd mysql# Useradd-g mysqlDecompress and compile# Tar-zxvf mysql-5.0.22.tar.gz# Cd mysql-5.0.22#./Configure -- prefix =/usr/local/mysql -- with-charset = gbk# Make# Make install# Cp support-files/my-medium.cnf/etc/my. cnfSet auto-start#

MySQL and Oracle conversion problem set: 1. mySQL does not support sequences. However, MySQL uses an auto-increment mechanism, and uses auto-increase in the ID column to replace sequences, when inserting SQL statements, enter Null in the position

Database Identity Authentication Database identity authentication is easy to understand, that is, the Database User Password is stored in the database in an encrypted manner. When a user connects to the database, the user name and password must be

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

The DBMS_RANDOM package provides users with random numbers. When DBMS_RANDOM is used, the RANDOM number seed is provided. The so-called RANDOM number seed is the value used in the RANDOM algorithm. In many programming languages, the seeds of two

Oracle uses triggers and sequence to achieve auto-Growth of primary keys Create a table -- Create tableCreate table GEO_BOOKMARK(F_ID NUMBER not null,F_NAME VARCHAR2 (100) not null,F_REMARK VARCHAR2 (200 ),F_XMIN NUMBER not null,F_YMIN NUMBER not

-- 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

1. HugePages description  1.1 HugePages Introduction HugePages is afeature integrated into the Linux kernel with release 2.6. This featurebasically provides the alternative to the 4 K page size (16 Kfor IA64) providing bigger pages.   There are some

When using Oracle, you can often use the following methods to view the tables that the current or specified users have permissions on. Method 1: Tables with permissions of the corresponding user are obtained based on the specified user name. SQL>

In Oracle databases, each user generally has his/her own data storage space such as data table space, temporary tablespace, and index tablespace, and you cannot write it to other tablespaces at will. For example, we often see tables built on users

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.

Observe the Oracle database performance. The awr feature provided by Oracle provides us with a nearly perfect solution. With awr features, we can extract awr reports from the database at any time. However, we need to provide some interactive

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

In Red Hat Linux, the following problems are encountered during the prerequisite detection during Oracle 10g installation: 1. Warning: there is not enough swap space in the memory. If there is a prompt that m is required to be smaller, how m is