Database Administrator

1. The relationship between Oracle sessions and processes Modified through SQLPlus is: Sessions = 1.1 * processes + 5 Use sys to log on with sysdba permissions: SQL> show parameter processes; Name type value -------- Aq_tm_processes integer

Grant, view, and manage user permissions in Oracle in Linux. In Oracle databases, user permissions are divided into two types (here we do not discuss the permissions of dba or role, but only the permissions of common users ), system Privilege System

One day, the system is switched from Windows to Linux, and Ubuntu is used. I started to build my web server, php5.2.6, mysql 5.0.45, nginx 0.5.35. Everything is normal, and phpinfo is also displayed. Next, we will start to build a project site. The

For example, if my user name is root and the password is 123 SQL script, the C disk name is test. The SQL database name is test. There are two ways to execute the script 1: Open CMD and enter the following command (directory conversion is not

Our server uses the server version of Ubuntu 8 and uses mysql as the server. However, every time we manage databases, we use SQL statements, which is very troublesome, especially when we add data, if there are ',; and other symbols in the added data,

Show variables like '% character %' After logging on to mysql by default in Linux Mysql> show variables like '% character % '; + -------------------------- + ---------------------------- +| Variable_name | Value |+ -------------------------- + ------

Sometimes it is not convenient to log on to the Linux graphical interface to install the Oracle client. We can use the silent mode to install, upgrade, and delete the oracle client (instead of the OUI ). Platform: RHEL4.5, oracle10.2.0.1 1. Silent

1. Install Python. The Python version is 2.4.2. 2. Install Mysql in/usr/local/Mysql 3. Obtain the MySQLdb Library 1). Download MySQLdb Library: http://sourceforge.net/projects/mysql-python from: MySQL-python-1.2.2.tar.gz Put this library

I. Account and system roles are combined to improve account security. An account is a name defined in the database system. It is the basic access control mechanism of the database. When connecting to the Oracle database, you need to enter the user

MySQL slow query record logs are useful for tracking MySQL load tuning issues in the PHP + MySQL system, such as installing a lot of Discuz! Plug-in users, so that you can probably find out which plug-ins have code problems. In fact, it is very easy

Profile is a set of names for password and resource restrictions. When an Oracle database is created, Oracle automatically creates a Default Profile and assigns it to users. If this parameter is not specified, the default profile is enabled. 1. view

If the system data is not updated, check the Oracle scheduled task. It is estimated that the task is not executed. The next_date is changed to 4000/1/1, and the broken is selected. Select * from user_jobs: the number of failed tasks of this task

This article describes how to build an Oracle database Server. The OS version is Red Hat Enterprise Linux Server release 4/5. In order to pursue higher performance, stability and economy, more and more companies are migrating their database servers

Environment: CentOS 6.2 + Oracle 11.2.0.3 Problem description: data cannot be started when oracle is installed or when you configure dataguard, error message ORA-00845: MEMORY_TARGET not supported on this system The main cause of this error is that

Today, I am free to test how to install the latest database MySQL5.6.11 under the latest CentOS 6.4. The installation of CentOS 6.4 is not described here CentOS 6.4 minimal installation Install MySQL5.6.11 using the source code package Initialize

I found this problem in my work: in Oracle versions earlier than 10 Gb, there is a bug that PreparedStatement preprocessing is used to dynamically query data, using placeholders? If the field is of the char type, it is used to replace it during

Db file scattered read For tables with frequent access, if no index is created or an appropriate index is not created, Oracle can only scan the entire table, resulting in a large number of waiting events.During full table scan, the read data is

Temporary Oracle tablespace is an important part of Oracle databases. Although this part is not presented in the cont architecture, its importance cannot be ignored. Especially for large-sized frequent operations, such as index creation and sorting,

The target database host to be imported is 10 Gb, and the source data host is 11 GB. To complete the migration, you need to use the function data pump added by Oracle in 10 Gb, in 11g, the data pump can define the version of the exported file. Now

Complicated and complex execution plans, developer eyes may be lost, resulting in a sexy and silly SQL statement running on the server. There are a few important parts here, as for others, of course, not to be polite ,, (I) Number of returned