1. A Guide to Oracle9i1 Introduction to Oracle9i Database Administration Chapter 11

2. A Guide to Oracle9i2 Lesson A Objectives Become familiar with database administration tasks Understand the process for installing an Oracle9i database, configuring client applications, and removing Oracle9i applications Learn how to use Oracle9i Enterprise Manager to perform database administration tasks Understand Oracle9i data storage structures Become familiar with Oracle9i database files

3. A Guide to Oracle9i3 Overview of Database Administration DBA tasks include: Install and upgrade the DBMS software on the server Optimize database performance by configuring how the database uses storage space in the server’s main memory and file system Create and maintain user accounts to control database access Monitor data storage space and allocate additional storage space as needed Start and shut down the database to perform database maintenance tasks

4. A Guide to Oracle9i4 Overview of Database Administration Perform backup and recovery operations Install and upgrade developer client utilities (such as Forms Builder and SQL*Plus) on developer client workstations Deploy finished database applications to users Assist developers in designing and creating database tables Assist developers in designing and creating form and report components and integrated database applications Assist in testing and debugging new applications Assist in training developers and users

5. A Guide to Oracle9i5 Installing an Oracle9i Database The three Oracle9i DBMS levels are: Enterprise Edition - the most powerful DBMS, and is appropriate for installations that require a large number of transactions performed by multiple simultaneous users Standard Edition - sufficient for high volume multiple- user installations Personal Edition - provides a single-user DBMS for developing database applications.

6. A Guide to Oracle9i6 Installing an Oracle9i Database Universal Installer utility –Allows you to view the Oracle Corporation products that are installed on a workstation –Guides you through the process of installing new products –Allows you to uninstall Oracle9i applications

7. A Guide to Oracle9i7 Installing an Oracle9i Database Universal Installer displays the following pages for the Oracle9i database installation: –File Locations page: specifies the location of the application source files and the location and name of the Oracle Home to which you wish to install the application –Available Products page: displays a menu showing the different products available for installation –Installation Types page: displays installation options for the selected product

8. A Guide to Oracle9i8 Installing an Oracle9i Database –Database Configuration page: specifies the properties of the preconfigured database that Universal Installer creates –Database Identification page: specifies the database name and instance name values that uniquely identify the database –Database File Location page: specifies the drive letter and folder path in which the database stores the files that contain the actual database data values

9. A Guide to Oracle9i9 Installing An Oracle9i Database –Database Character Set page: specifies the character set or sets that the database uses to store character data –Configuration Tools page: configures properties of the predefined database and configures the database network properties –End of Installation page: signals the end of the installation process, and provides messages and other details about the installation process

10. A Guide to Oracle9i10 Configuring Client Applications to Connect to an Oracle9i Database To connect to an Oracle9i database, you type a connect string in the Host String field on the Log On dialog box in SQL*Plus, or in the Database field in the Connect dialog box in Forms Builder The connect string provides Oracle Net the information it needs to create a connection between the client application and a specific database instance

11. A Guide to Oracle9i11 Configuring Client Applications to Connect to an Oracle9i Database To configure connect strings for client applications that connect to databases that are not on the same workstation as the database server, you use one of the following approaches: –Local naming –Oracle Internet Directory

12. A Guide to Oracle9i12 Configuring Client Applications to Connect to an Oracle9i Database Local Naming - The local naming approach stores connect string and database connection information in a file named tnsnames.ora on the client workstation Oracle Net uses a connect descriptor to route a client data request to a specific Oracle9i DBMS. It specifies: –Network communication protocol –IP address of the database server –Database instance name

13. A Guide to Oracle9i13 Configuring Client Applications to Connect to an Oracle9i Database Oracle Internet Directory stores connect descriptor and service name information on a directory server called an Oracle Internet Directory (OID) server A directory server specifies the location of servers on a network An OID server uses the Lightweight Directory Access Protocol (LDAP) which is a standard protocol for configuring a directory server –LDAP specifies that the directory server contains entries for each server process in a specific format

14. A Guide to Oracle9i14 Configuring Client Applications to Connect to an Oracle9i Database To use an Oracle Internet Directory server –a client database application requests to connect to an Oracle9i database by contacting the OID server and specifying the LDAP server entry for the desired database, as shown in the next slide

15. A Guide to Oracle9i15 Removing an Oracle9i Database You can use Universal Installer to remove Oracle9i applications from a server or workstation Universal Installer does not remove all elements from the registry To completely remove an Oracle9i database or client application from a workstation, you must perform the following operations: –Manually edit the system registry to remove all Oracle9i-related entries –Restart the workstation –Manually delete all Oracle9i-related files and folders

16. A Guide to Oracle9i16 Using OEM to Perform DBA Tasks OEM = Oracle Enterprise Manager – a utility that allows DBAs to perform database administration support tasks Universal Installer installs OEM on the server or workstation when you install any Oracle9i database OEM has a three tier architecture as shown in the next slide

17. A Guide to Oracle9i17 Using OEM to Perform DBA Tasks Oracle Enterprise Manager Architecture

18. A Guide to Oracle9i18 Using OEM to Perform DBA Tasks Console – where the DBA performs administration tasks Oracle Management Server – an Oracle9i database server that supports database administration tasks in an organization. The OMS interacts with the repository Repository – contains information for remotely administering different databases The OMS then interacts with different database servers in Tier 3

19. A Guide to Oracle9i19 Using OEM to Perform DBA Tasks Through OEM you access different database objects to perform various database administration tasks Database objects include: instance, schema, security, storage, distributed, warehouse, workspace, XML database

20. A Guide to Oracle9i20 Using OEM to Perform DBA Tasks Instance - provides information about the database instance, allows the DBA to edit instance information, and allows the DBA to start up and shut down the instance Schema - allows the DBA to examine and manipulate database objects (such as tables, sequences, indexes, and views) in all user schemas Security - allows the DBA to create and manage user accounts Storage - provides information about existing database storage structures and allows the DBA to create and configure storage structures

21. A Guide to Oracle9i21 Using OEM to Perform DBA Tasks Distributed - allows the DBA to support applications and databases that are distributed across multiple database servers Warehouse - provides applications that allow DBAs and database developers to analyze database contents and look for long-term trends Workspace - allows DBAs and other users to view and maintain different versions of the same data XML Database - allows DBAs and database developers to create an XML database based on Oracle9i database tables

22. A Guide to Oracle9i22 Managing Oracle9i Data Storage Data structure provides a framework to organize data that a computer stores Tables, lists, and arrays are examples of data structures Oracle9i data structures have a hierarchical relationship

23. A Guide to Oracle9i23 Managing Oracle9i Data Storage Database Instance – stores data in one or more tablespaces Tablespace - stores related database objects Segments - stores an individual database object, such as a table or an index Extent - a contiguous unit of storage space within a segment Data Block - smallest storage unit that the database can address. Extents consist of data blocks

24. A Guide to Oracle9i24 Managing Oracle9i Data Storage Each Data Block consists of: header, free space and row data Header - contains information about the data block contents, and is made up of three separate subsections: the block header, the table directory, and the row directory Free space - is empty space that the block retains in case users update the data within the data block, and the updated data occupies more storage space than the original data Row Data – stores actual data values

25. A Guide to Oracle9i25 Managing Oracle9i Data Storage Data Block Components

26. A Guide to Oracle9i26 The Oracle9i Database File Architecture An Oracle9i database is made up of several different files that reside in the file system of the database server workstation. These files include: Parameter files - initialize the database specifications and point to the locations of the database control file Control files - contain information about the database tablespaces, datafiles, redo log files, and the current state of the database

27. A Guide to Oracle9i27 The Oracle9i Database File Architecture Datafiles – contain the actual data values Redo log files - contain rollback information for uncommitted transactions An Oracle9i database stores rollback information in redo log files in a data structure called a rollback segment A rollback segment is made up of data blocks configured in a circular fashion As users perform action queries, the DBMS adds new rollback information to the rollback segment data blocks

28. A Guide to Oracle9i28 The Oracle9i Database File Architecture Rollback Segment

29. A Guide to Oracle9i29 Lesson B Objectives Create and manage user accounts Understand an Oracle9i database instance’s memory areas and background processes Learn how to start and shut down the database Understand Oracle9i database backup and recovery

30. A Guide to Oracle9i30 Creating and Managing User Accounts When you create a new user account you must specify the following: –Username, Password, default tablespace and temporary tablespace –System privileges the user has in the database –User’s tablespace quota on the database server

31. A Guide to Oracle9i31 Creating and Managing User Accounts System Privilege - allows a user to perform a specific task with the Oracle9i database, such as connecting to the database or creating a new table Object Privilege - allows a user to perform a specific action on a database object, such as selecting data from a table or retrieving a value from a sequence

32. A Guide to Oracle9i32 Creating and Managing User Accounts Tablespace Quota - A user’s tablespace quota specifies –Amount of disk space that the user’s database objects can occupy in his or her default tablespace A role is a database object that represents a collection of system privileges that you can assign to multiple users

33. A Guide to Oracle9i33 Components of an Oracle9i Database Instance In an Oracle9i client/server database, a client process that runs on the client workstation connects to a database instance that runs on the database server The link between the client process and the database instance is called a connection, and it creates a user session A database instance consists of a set of processes and associated memory structures that manipulate data in a database’s tablespaces

34. A Guide to Oracle9i34 Components of an Oracle9i Database Instance An Oracle9i database instance creates two memory areas in the database server’s main memory: –System Global Area –Program Global Area The System Global Area (SGA) is a memory area that all database connections use. The purpose of the SGA is to share information among all database processes. The SGA is made up of five primary memory areas: shared pool, database buffer cache, large pool, redo log buffer, Java Pool

35. A Guide to Oracle9i35 Components of an Oracle9i Database Instance Primary Memory Areas Within the System Global Area

36. A Guide to Oracle9i36 Components of an Oracle9i Database Instance The Program Global Area (PGA) is a memory area that stores information for a specific user connection. The PGA contains two separate memory areas : session information and stack space The session information area contains information about the user session, such as the username, time the session started, date of the last activity, and global variable values The stack space contains the values of the variables that the user declares in PL/SQL programs and other programs

37. A Guide to Oracle9i37 Components of an Oracle9i Database Instance Memory Areas Within the Program Global Area

38. A Guide to Oracle9i38 Components of an Oracle9i Database Instance An Oracle9i database instance contains a set of background processes to service user requests The Oracle9i background processes include: DBWn, LGWR, SMON, PMON, and CKPT DBWn - writes changed data from the database buffer cache to the datafiles LGWR - writes redo information from the redo log buffer to the redo log files

39. A Guide to Oracle9i39 Components of an Oracle9i Database Instance SMON - has three primary functions: –Recover lost data after a system hardware or software failure –Deallocate temporary memory areas that the database uses for sort operations –Manage server disk space by periodically coalescing free space to make larger continuous extents for new data PMON - monitors and manages individual user sessions CKPT - responsible for initiating checkpoints. A checkpoint signals the DBWn and LGWR processes to write the buffer contents to the datafiles and redo log files

40. A Guide to Oracle9i40 Starting and Shutting Down the Database Database administrators must shut down a database periodically to perform maintenance tasks such as: –Backing up the database –Adding new datafiles –Modifying the properties of the parameter file –Recovering from a database crash After the DBA performs the maintenance activity, he or she restarts the database to make it available for new user connections

41. A Guide to Oracle9i41 Starting and Shutting Down the Database When a DBA shuts down an Oracle9i database instance, the DBA has four different options for how the shutdown process handles existing user connections: –Normal –Transactional –Immediate –Abort

42. A Guide to Oracle9i42 Starting and Shutting Down the Database Normal - instance does not accept any new connections, but allows current users to finish their transactions and log off normally Transactional - instance does not accept any new connections, and allows users to finish their current transaction Immediate - instance does not accept any new user connections, and immediately terminates current user connections Abort - immediately disconnects all users, stops the instance’s processes, and reallocates all server memory

43. A Guide to Oracle9i43 Starting and Shutting Down the Database When a DBA starts an Oracle9i database instance, he or she can start it in one of three modes: –Unrestricted: allows all users to create connections –Restricted: creates connections only for users who have the RESTRICTED SESSION system privilege –Read-only: allows users to read database contents, but does not allow users to perform action queries that modify database contents

44. A Guide to Oracle9i44 Starting and Shutting Down the Database When a DBA shuts down a database instance using the Normal, Transactional, or Immediate shutdown option, the shutdown process performs the following tasks: –Writes the contents of the data buffer cache to the datafiles –Writes the contents of the redo log buffer to the redo log files –Closes all files –Stop all background processes –Deallocates the SGA in the server’s main memory NOTE: When a DBA restarts a database instance, the startup process performs these tasks in the reverse order

45. A Guide to Oracle9i45 Database Backup and Recovery Important database administration support tasks include –Backup: creating a copy of the database files –Recovery: restoring the database to a working state after a hardware or software malfunction Backup operations on an Oracle9i database can be classified as: –Offline (cold) backups –Online (hot) backups

46. A Guide to Oracle9i46 Database Backup and Recovery Offline Backup – (cold backup) requires shutting down the database, then copying all of the database files to an alternate location Online Backup – (hot backup) involves backing up critical database files while the instance is running, as well as creating an ongoing archive of database changes so the DBA can restore the database to its state at any point in time

47. A Guide to Oracle9i47 Summary Database administration involves installing, configuring, maintaining, and troubleshooting a database Oracle9i database exists at three levels: Enterprise Edition, Standard Edition, and Personal Edition Universal Installer pages guide you through the installation process You can use local naming to configure client applications to connect to an Oracle9i database OEM allows DBAs to perform database administration support tasks

48. A Guide to Oracle9i48 Summary A database instance stores data in one or more tablespaces Parameter file specifies configuration information about an Oracle9i database instance Control files store information about the database structure and state Redo log files record information to undo action query changes through user rollback operations An Oracle9i database stores the rollback information in a rollback segment

49. A Guide to Oracle9i49 Summary When creating a new user account, you must specify general information about the user account, system privileges, and the user’s tablespace quota System privileges allow users to perform specific tasks with the Oracle9i database A role represents a collection of system privileges that you can assign to multiple users

50. A Guide to Oracle9i50 Summary An Oracle9i database instance creates the System Global Area (SGA) and the Program Global Area (PGA) DBA can start an Oracle9i database instance in unrestricted, restricted or read-only mode Backup involves creating a copy of the database files, and recovery involves restoring the database to a working state after a hardware or software malfunction