1. Oracle8/8i Database Administration
Draft V0.7
4/15/2002

2. Course Objectives Starting up and Shutting down database
Creating an Oracle Database
Managing Oracle database files
Managing tablespces,segments,extexts and block
Managing users,privileges and resources
Using National Language Support

3. Oracle 8i Database Family
• Oracle8i Lite - Mobile internet computing
• Personal Oracle8i ideal for consultants, developers and students
• Oracle8i pre-tuned and pre-configured for today’s dynamic
workgroup and line-of-business environments
• Oracle8i Enterprise Edition for developing and deploying
mission-critical enterprise intranet and Internet applications
• Oracle8i Options - A Platform for Any Intranet or Internet Application

4. Oracle 8i Options
Oracle8i Options - A Platform for Any Intranet or Internet Application
Creating intranet and Internet applications presents a new set of challenges and requirements for developers. Internet-savvy applications need to run on any platform without high management overhead. They have to be inviting, and rich in multimedia content. They have to be interactive, yet highly automated to provide smooth, reliable, and secure transactions over the Web. They’ll be distributed across timezones, so they have to be available all the time. And they have to be flexible enough to serve an increasingly mobile workforce.

5. Database Administration Tasks
Managing database availability
Planning and creating database
Managing physics structure
Managing storage base on design
managing security
Network administration
Backup & Recovery
Database tuning

6. Database Architectural Components

7. Database Architectural Components
Server Process
Sql Net
User Process
Net8 --
GID – Global ID (Ex: )
SID – System ID (Ex: ORCL)

8. Database Architectural Components
User Process
Run on the client machine
Is spawned when a tool or an application is invoked
Sql plus ,Server Manager,OEM,Designer,Developer
includes the User Program Interface (UPI)
Calls to the Oracle Server

9. Database Architectural Components
Server Process
Run on the Sever machine (host)
Services a single user process in
dedicated server configuration
Users an exclusive PGA
Include Oracle Program interface (OPI)
Process calls by client
Returns to the client

10. Database Architectural Components
Oracle Instance
Oracle Server consists of Oracle Instance and Oracle database
Memory Structure SGA & Background Process
Identified by setting ORACLE_SID , can open and use only one database at any point of time

11. ORA 7/8 : Architectural Components

12. Database Architectural Components
System Global Area - SGA
Shared Pool :
used to store information such as the most SQL & data
from data dictionary
Database Buffer Cache :
used to store the most recently used data
Redo Log Buffer :
used to register changes made to the database

13. SGA – Process, PGA

14. Glossary : SGA

15. SGA

16. Process
Database Files
Control Files
Redo Log Files
(Parameters File)

17. Database Architectural Components
Processing a Query
Parse - check & compile the statement in the Shared Pool
Execute - Prepare to retrieve data
Fetch - retrieve the data rows
The Shared Pool
Size defined by : SHARED_POOL_SIZE
Library Cache : Text,parse tree,execution plan of Sql statement
Data Dictionary Cache : Contains table and column definitions and privileges ,user,password also known as
Dictionary cache or row cache.

18. Database Architectural Components
Database Buffer Cache
• Stores the most recently used blocks
• Number of buffers defined by DB_BLOCK_BUFFERS
• Size of the buffer based on DB_BLOCK_SIZE
The Oracle Server use a Least Recently Used (LRU) algorithm to age
out buffers that have not been accessed recently to make away for
new blocks to be accommodated in the buffer cache.

20. Database Architectural Components
Redo Log Buffer
• Size defined by LOG_BUFFER
• Records changes made though the instance
• Used sequentially
• Circular buffer

21. PGA – Program / Process Program Global Area (PGA)
• Also know as Process global area only for one process
• not shared and not writable.
• Contains
- Sort area (sort rows before data returned to the user)
- Session information (User privileges for the session)
- Cursor State (Cursor used by the session)
- stack space (session variables)

22. Architectural Components – Data Flow
Processing a DML Statement
Instance
3. Place locks on data
Update emp SET
sal=sal* 1.1
WHERE empno=7369
SGA
Library
Cache
4. Before (Rollback)/ After image new value
Server Process
2. Copy data to db buffer
DB Buffer
Redo Log
Data
dictionary
5. Before image - rollback block
updated to data block and marked
as Dirty Buffers
Control File
1. Data & Rollback Blocks
Data File
Log File

23. Background Process Database Writer (DBWR) Log Writer (LGER)
System Monitor (SMON) (recovery and space management)
Process Monitor (PMON) (cleans transactions)
Check point (CKPT)
Archive (ARCH)
Recover (RECO) (On the distributed database system)
Lock Processes (LCK0-9) - For parallel, for remote database
Server Process (S000-S999) (MTS)
Dispatcher Process (D000-D999). (MTS)

24. Database Architectural Components
Background Process
Database Writer (DBWR)
Write dirty buffers from database buffer cache to the data file
Trigger Event
1. When dirty buffers reaches a threshold value
2. When no more free buffers
3. A timeout occurs
4. A checkpoint

25. LGWR – Log Writer Background Process Log Writer (LGWR) Trigger Event
Write log buffer into redo log files,write redo log sequence
number to data file and control file and tells DBWR to write dirty
buffers to disk
Trigger Event
1. When redo log buffer is one - third full
2. When timeout occurs (3 seconds)
3. Before DBWR active
4. When a transaction commits

26. Database Architectural Components

27. Tablespace : SYSEM, USERS

28. Logical View vs. Physical View
Segment
Extent
Tablespace

29. Snapshot Show
GUI Viewpoint

30. MEORCL
Instance Name: (ORCL)

31. MEORCL – Instance Name

32. Help

33. Glossary: Segment

34. Rollback Segment

35. Physical Files – ORACLE
Database Files
Data files - store the data dictionary,user objects
before/after images for the transactions (at least 1)
Redo log files - changes made to the database for later recovery
(at least 2)
Control files - contain the information need to maintain and verify
database integrity (at least 1)
Parameter file - define the characteristics of the Oracle Instance
Password file - used to authenticate privileged database user
Archived redo log files - offline copies of redo log files that may be
necessary to recovery from media failures

36. 2. Managing an Oracle Instance
Objectives
• Setting up system and password file
• Creating the parameter
• Starting up an instance and opening the database
• Closing a database and shutting down database
• Getting and setting parameter values
• Managing sessions
• Monitoring ALTER and trace files

37. Managing an Oracle Instance
Connect as internal / sysdba
The ability to connect as internal is provided for backward compatibility.
In the future, the DBA can connect to the database for the purposes of
administration using the connect name/pass as sysdba command.
The sysdba keyword denotes a collection of privileges that are
akin to those privileges granted with the internal keyword.

38. Managing an Oracle Instance
Sysdba/sysoper osdba/osoper
The sysoper/osoper privilege handles administration of the following privileges:
Starting and stopping the Oracle instance
Mounting or opening the database
Backing up the database
Initiating archival of redo logs
Initiating database recovery operations
Changing database access to restricted mode
. The sysdba privilege administers certain other privileges as well.
The sysoper/osoper privilege
All system privileges granted with admin option
The create database privilege
Privileges required for time-based database recovery

39. Managing an Oracle Instance
Database Startup
- Start an instance (INITSID.ORA)
- Mount the database (Control File)
- Open the database (Data Files)
Database Shutdown
- Close the database
- Dismount the database
- Shutdown the instance

40. Managing an Oracle Instance
Database Startup
Start an instance
- Reading the parameter file
- Allocate SGA
- Starting the Background Process
- Open the trace and the ALERT file
Mounting the database
- Reading the control file
- Associating a database
- obtain the names and status of data & log files
for renaming data file,enable,disable archive
and performing full database recovery
Opining the database
- Opening the online data file
- Opening the online redo logfiles
- check the consistency of the database SMON initiates
the instance recovery

41. Startup – Instance Database Startup Command
STARTUP [force] [restrict] [pfile=filename]
[exclusive | parallel | shared]
[open [recovery] [database]
| mount
| nomount ]
Change Status
ALTER database {mount | open}
Troubleshooting (Start Oracle Services)
ORA : TNS : lost contact
ORA : Windows 32 bits drive unable to spawn new oracle
task

42. SVRMGRL– StartUp /Shutdown

43. Connect Internal/PWD

44. Shutdown Database Shutdown Options Shutdown mode A I T N
Allow new connection n n n n
Wait until session end n n n y
Wait until the transactions n n y y
Force a checkpoint and close n y y y
SHUTDOWN [NORMAL | TRANSACTIONAL
| IMMEDIATE | ABORT]

45. Managing an Oracle Instance
Demo & Practice - Database Startup & Shutdown

46. Managing an Oracle Instance
Database Administrator Users
SYS and System are
- automatically created
- Granted the DBA role
SYS Password change_on_install
- Owner of the data dictionary
System - Password manager
- Owner of the additional internal tables
used by Oracle Tools
Create additional User for daily DBA activities

47. Managing an Oracle Instance
Operating System Authentication
• Setup the user to be authenticated by the OS
• Set REMOTE_LOGIN_PASSWORDFILE=NONE
• Use the following command to connect to the database
CONNECT / AS SYSDBA
CONNECT / AS SYSOPER
Unix - the user must be the Unix group user DBA
- View /etc/group and /etc/password to
determine the member of Unix group
Windows NT - Create group called ORA_<SID>_DBA and
ORA_<SID>_OPER
- Add NT the CONNECT INTERNAL
User to the group

48. Managing an Oracle Instance
Using Password File Authentication
• Create the password file using Password v$pwfile_users
orapwd (80) file=<filename> password =<password>
entried= <entries>
filename - password file
password - password
Entries - max no of dba
• Set REMOTE_LOGIN_PASSWORDFILE to EXCLUSIVE
or SHARED
Exclusive - only one instance names other than
SYS SYSTEM
Shared - more than one instance but only
recognized SYS and Internal
• On Unix $ORACLE_HOME/dbs
On Windows NT %OARCLE_HOME%\DATABASE

49. Managing an Oracle Instance
Changing the internal Password
• Use the password utility on NT and UNIX to delete and create the password file or
• Use the ORADIM utility on NT to delete and create a
new password file NT
- Delete password file C:\ >ORADIM -DELETE -SID sid
- Recreate c:\>ORADIM80 -NEW -SID sid -INTPWD pwd -
MAXUSER n

50. Managing an Oracle Instance
The Initialization Parameter File
• Refereed to as the init<SID>.ora file
• Locate in $ORACLE_HOME/dbs on UNIX
%ORACLE_HOME%/database on NT
Using of parameter :
- size the SGA to optimize performance
- set instance and database default & limit
- define the physics attributes of the database (db block)
- specify control, archive & trace file location
Rule to specify the parameter
- format keyword=value
- the server has a default for each value
- # to commit the parameter,double quotation for char.
- IFILE to include additional parameter
Note : OEM starting a remote database requires the parameter files
to be stored on the computer that running the OEM

51. Init.ORA – Parameter The Initialization Parameter File
DEMO - Parameter file example
- How to modify the Init.ora file
- the important parameter

52. Shutdown and then StartUp
Dynamic Performance Views
Maintained by the Oracle Server
Contain the data that useful for performance tunning
Contain data on the disk and memory struceures
v_$ but oracle provide public Synonyms v$
the view v$FIXED_TABLE display all the views info.
Accessing Dynamic Performance views
OPEN
Data dictionary
MOUNT
NOMOUNT
Disk
SHUTDOWN
memory

53. Startup an Instance
NoMount / Mount / Open

54. Managing an Oracle Instance
Dynamic Performance Views
V$PARAMETER
V$SGA
V$OPTION
V$PROCES
V$SESSION
V$VERSION
V$INSTANCE
SGA
V$THERAD
V$CONTROLFILE
V$DATABASE
V$DATAFILE
V$DATAFILE_HEADER
V$LOGFILE
Control File

55. Managing an Oracle Instance
Displaying Current Parameter Values
. Use the server Manager / SHOW PARAMETER
. Query the v$parameter

56. Managing an Oracle Instance
Dynamic initialization Parameter
Some initialization parameter can be modified while
the instance is running
ALTER SESSION SET SQL_TRACE=true;
ALTER SYSTEM SET TIMEDSTATISTICS=true;
ALTER SYSTEM SET SORT_AREA_SIZE=131072;
ALTER SESSION modifies only the value of current session
ALTER SYSTEM Changes the global values
DEMO - Check the v$parameter

57. Managing an Oracle Instance
Enable and disable restricted Session
START RESTRICT
ALTER SYSTEM ENABLE RESTRICTED SESSION;
Usage :
- structure maintenance
- database export import

58. Managing an Oracle Instance
Terminating Session
1. Identify the user session from V$SESSION
SELECT sid ,serial# from v$session;
2. Execute the ALTER SYSTEM command
ALTER SYSTEM KILL SESSION ‘8,16’;

59. Managing an Oracle Instance
Trace files
- trace file can be written by server and background process
- Oracle dumps the information in trace files
- the ALERT file consist of a all the messages and errors
- Server process tracing can be enable & disabled by
ALTER SESSION set SQL_TRACE=TRUE;
Parameters:
BACKGROUND_DUMP_DEST
USER_DEMP_DEST
MAX-DUMP_SIZE
alter<SID>.LOG UNIX $ORACLE_HOME/RDBMS/LOG
NT %ORACLE_HOME%/RDBMS/TRACE

60. Managing an Oracle Instance
Guidelines for the ALERT file
. Detect internal errors (ORA-00600) and block corruption errors.
. Monitor database operations
STARTUP,SHUTSOWN,ARCHIVE LOG,RECOVER
. View the nondefault initialization parameter

61. Managing an Oracle Instance
Summary
. Starting up and shutdown an instance
. Understanding the use of dynamic performance views
. Describing the use of trace files

62. PDF /Book

63. PDF / Read it to get Concepts

64. Q&A :Index

66. Clustered vs. Non-Clusterd

68. Q&A : SQLplus

69. Questions & Answer???