Database Administrator

Oracle 10 Gb provides a way to use external tables to extract data. First, you need a directory (here we will continue to use the previously created directory) SQL> showUser USERIs"SYS" SQL>Select*FromDba_directoriesWhereDIRECTORY_NAMELike '%

You can use the decode function to convert columns in Oracle: If there is A student Table: ID NAME SUBJECT SCORE 1 Zhang San Chinese 90 2 Zhang San Mathematics 80 3 Li Si Chinese

There are two tables: book and book_copy. You need to delete all the records in the book table that are equal to each other according to some fields in the book_copy table. The stored procedure is as follows: Create or replace procedure

Manual database creation 1. manually create a database 1. Create a folder. (Based on the directory in/u01/app/Oracle/admin/orcl, we also created it)$ Mkdir-p/u01/app/oracle/admin/mydb/adump$ Mkdir-p/u01/app/oracle/admin/mydb/bdump$

1.System PermissionsUnlimited tablespaceIs hidden inDba, resourceA system permission in the role. When the user obtains the role of dba or resource,The unlimited tablespace system permission is also implicitly authorized to the user. 2.System

Assume that there are three log groups, each of which has one member and the size of each member is 1 MB. Now we want to change the size of all three log groups to 10 MB.1. create two new log groupsAlter database add logfile group 4 ('d: \ Oracle \

To enable OEM or OMS properly, there are two key points:1. Whether the Oracle system service is enabled;2. Are the usernames and passwords used for Logon correct. First, let's talk about Oracle's system services. In the case of full installation,

Abstraction of Oracle's Structure System An avid photographer-happy family of Old Wang     The first chapter of each ORACLE book generally introduces the structure and system of ORACLE. When this chapter is opened, readers will suddenly fall into an

The following error occurs when I log on to the system. If I run any command during package expansion, an error is returned: Last login: Thu Nov 10 08:32:12 2011 from 134.224.55.126ERROR: ld. so: object '/etc/libcwait. so' from/etc/ld. so. preload

1. Connect to the database: Cx = sqlite3.connect ('database. db'). cx is a database connection object and has the following operations: Commit () -- transaction commit Rollback () -- transaction rollback Close () -- close a database

As An ORM framework, Hibernate needs to consider loop and SQL statements. It is mainly reflected in session usage, lazy usage, outjoin usage, and batch-size usage. The following details 1. For session usage, a tool class should be provided to

This experiment is to restore the spfile: SQL> shutdown immediate;Database closed.Database dismounted.Oracle instance shut down.SQL> startup nomount;ORACLE instance started. Total System Global Area 335544320 bytesFixed Size 1219280 bytesVariable

1. In the http://www.oracle.com/technetwork/database/index.html, enter the Instant Client for Linux x86 page, Then download the following installation package (10 Gb client, 11 GB latest

I haven't checked my Oracle for a long time. I'm afraid I forgot my password. I just plan to use TOAD to check my ORACLE. When I open the connection, an error is returned: ORA-12514 TNS listeners currently cannot identify request services in

Many of my friends have made mysql master and slave databases for a while, but sometimes they have taken a lot of detours and wasted a lot of time. The main problem is that there is no information about other ChaYue host configurations, I only read

The Sample function is used to support data mining. The Sample function allows data analysis to be performed on the Sample data, rather than on the entire table. Select record 10%Select * from atest sample (11)Select record 0.1%Select * from atest

Measure the test taker's understanding about the operations in a table in El. Goal: Learn about table creation and modification and related operations. Preface: Oracle: The table is created in the user solution, rather than directly belongs to the

First install CentOS6.0 ============== Not to mention. Install it. The only thing to note is that the Checking the Software Requirements section in the Oracle 11G Installation guide will require the Installation of some Software. These software are

1. Check the character set when the Oracle database is created:Oracle Server executionSQL> select name, value $ from sys. props $ where name like 'nls % ';Name value $----------------------------------------------------------------------NLS_LANGUAGE

1. Install the compiling environment 1 yum install gcc gcc-c++ autoconf automake ncurses-devel 2. Download and decompress 1 wget http://mysql.mirror.tw/Downloads/MySQL-5.1/mysql-5.1.45.tar.gz 2 tar