Database Administration and Management

Transcription

1 Database Administration and Management M.Sc. Information Technology BS Information Technology Umair Shafique (Gold Medalist) Lecturer

2 Installation

3 Oracle Installation and Starting Manual for Installation and Configuration is shared

4 What Is SQL? SQL provides statements for a variety of tasks, including: Querying data Inserting, updating, and deleting rows in a table Creating, replacing, altering, and dropping objects Controlling access to the database and its objects SQL unifies all of the preceding tasks in one consistent language.

5 Establishing a Connection and Creating a Session Connection The user starts the application or tool on a local computer and connects over a network to the computer running the Oracle Instance. In this configuration, called client-server, network software is used to communicate between the user and the Oracle server. In a three-tiered connection, the user s computer communicates over the network to an application or a network server, which is connected through a network to the machine running the Oracle Instance. Sessions A session is a specific connection of a user to an Oracle server. The session starts when the user is validated by the Oracle server, and it ends when the user logs out or when there is an abnormal termination. For a given database user, many concurrent sessions are possible if the user logs on from many tools, applications, or terminals at the same time. Except for some specialized database administration

6 Connecting to an Oracle Instance Creating a Session

7 Using SQL There are several tools for interfacing with the database using SQL: Oracle SQL*Plus and isql*plus Oracle Forms, Reports, and Discoverer Oracle Enterprise Manager Third-party tools

8 SQL*Plus Overview SQL*Plus is an interactive and batch query tool that is installed with every Oracle Database installation. It has a Command Line user Interface (CLI), a Windows Graphical User Interface (GUI) and the isql*plus web-based user interface.

9 SQL*Plus Overview (continue) SQL*Plus has its own commands and environment, and it provides access to the Oracle Database. It enables you to enter and execute SQL, PL/SQL, SQL*Plus and operating system commands to perform the following: Format, perform calculations on, store, and print from query results Examine table and object definitions Develop and run batch scripts Perform database administration You can use SQL*Plus to generate reports interactively, to generate reports as batch processes, and to output the results to text file, to screen, or to HTML file for browsing on the Internet. 9

10 Sample Schemas and SQL*Plus Sample schemas are included with the Oracle Database. Examples in this guide use the EMP_DETAILS_VIEW view of the Human Resources (HR) sample schema. This schema contains personnel records for a fictitious company. To view column details for the view, EMP_DETAILS_VIEW, enter DESCRIBE EMP_DETAILS_VIEW

11 Starting Up a Database Using SQL*Plus You can start a SQL*Plus session, connect to Oracle Database with administrator privileges, and then issue the STARTUP command. You can also start a DB by: Starting Up a Database Using Recovery Manager Starting Up a Database Using Oracle Enterprise Manager

12 SQL*Plus Overview SQL*Plus is an interactive and batch query tool that is installed with every Oracle Database installation. It has a Command Line user Interface (CLI), a Windows Graphical User Interface (GUI) and the isql*plus web-based user interface.

13 SQL*Plus Overview (continue) SQL*Plus has its own commands and environment, and it provides access to the Oracle Database. It enables you to enter and execute SQL, PL/SQL, SQL*Plus and operating system commands to perform the following: Format, perform calculations on, store, and print from query results Examine table and object definitions Develop and run batch scripts Perform database administration You can use SQL*Plus to generate reports interactively, to generate reports as batch processes, and to output the results to text file, to screen, or to HTML file for browsing on the Internet. 13

14 Who Can Use SQL*Plus The SQL*Plus, SQL, and PL/SQL command languages are powerful enough to serve the needs of users with some database experience, yet straightforward enough for new users who are just learning to work with the Oracle Database. E.g. to list column definitions for the EMPLOYEES table, enter the command: DESCRIBE EMPLOYEES

15 SQL*Plus Quick Start These instructions are to enable you to login and connect to a database after you have installed SQL*Plus. You can connect to the default database you created during installation, or to another existing Oracle database.

16 SQL+

17

18 LOGIN- GUI

19 LOGIN- CLI Command-line tool Used interactively or in batch mode $ sqlplus /nolog SQL*Plus: Release Production on Tue Feb 17 06:17: Copyright (c) 1982, 2004, Oracle. All rights reserved. SQL> connect ric Enter password: Connected. SQL> SELECT * FROM dual; D - X SQL>

20 Who Can Use SQL*Plus The SQL*Plus, SQL, and PL/SQL command languages are powerful enough to serve the needs of users with some database experience, yet straightforward enough for new users who are just learning to work with the Oracle Database. E.g. to list column definitions for the EMPLOYEES table, enter the command: DESCRIBE EMPLOYEES

21 Login Username and Password When you start SQL*Plus, you need a username and password to login to an Oracle Database schema. Your username and password identify you as an authorized user of the Oracle Database schema. The database administrator (DBA) is responsible for creating your database account with the necessary privileges and giving you the username and password that enables you to access your account. Default logins are created and you are prompted for associated passwords during Oracle Database installation. Some of the default login usernames created are: SYS SYSTEM HR SCOTT Logins are created and displayed in messages during Oracle Database installation.

22 GUI Login Screen 22

23 Starting Command-line SQL*Plus To begin using SQL*Plus, you must first understand how to start and stop SQL*Plus. Starting SQL*Plus This example shows you how to start SQL*Plus: Make sure that SQL*Plus has been installed on your computer. Log on to the operating system (if required). Go to RUN Enter the command, SQLPLUS, and press Return.

24 Shortcuts to Starting Commandline SQL*Plus When you start SQL*Plus, you can enter your username and password, separated by a slash (/), following the command SQLPLUS. For example, you can enter SQLPLUS HR/your_password and press Return.

25 CLI Login Screen For your protection, your password does not appear on the screen. 25

26 Exiting SQL*Plus The way you exit SQL*Plus from each of the three user interfaces is described in the following sections. If you fail to log in to SQL*Plus successfully because your username or password is invalid or some other error, SQL*Plus will return an error status equivalent to an EXIT FAILURE command.

27 Exiting the Command-line User Interface When you are done working with SQL*Plus and wish to return to the operating system, enter EXIT or QUIT at the SQL*Plus prompt, or enter the end of file character, Ctrl+D on UNIX or Ctrl+Z, Ctrl+C on Windows. SQL*Plus displays the version of Oracle Database from which you disconnected and the versions of tools available through SQL*Plus. After a moment you will see the operating system prompt.

28 Exiting the Windows Graphical User Interface You can exit the Windows GUI in exactly the same way as you exit the command-line user interface, by entering EXIT or QUIT at the SQL*Plus prompt. You can also click Exit from the File menu to exit the Windows GUI and return to Windows.

29 Changing your Password In the command-line interface, you can change your password with the PASSWORD command. To change the password of another user, you must have been granted the appropriate privilege. Expired Password In the command-line interface, if your password has expired, SQL*Plus prompts you to change it when you attempt to log in. You are logged in once you successfully change your password.

30 Examples If you want to change your current password, enter PASSWORD Changing password for your_password Old password: your_password New password: new_password Retype new password: new_password Password changed

31 Example If you are logged on as a DBA, and want to change the password for user johnw (currently identified by johnwpass) to johnwnewpass PASSWORD johnw Changing password for johnw New password: johnwnewpass Retype new password: johnwnewpass Password changed

32 Command in SQL*Plus Connect to a database CONNECT [ [ username [ /password ] ] [ / AS { SYSOPER SYSDBA } ] ] SQL> connect system/sys Connected.

33 Some Commands DISCONNECT CONNECT STARTUP SHUTDOWN Quit/Exit Clear Scr Edit Help etc

34 Basic Commands SELECT * FROM tab; desc <table name>; set lines 3000 set pages 1500 show User clear scr ed /

35

36

37

38

39

40