1. Goals for This Week Brief SQL refresh New SQL in Oracle 9i
Overview of Oracle Architecture
Basic Oracle Administration
Performance Tuning
Schema Design
Back-end Tools

2. Switch to SQL Intro

3. Role of Database Server
Results
SQL or
Procedure Call
SQL or
Procedure
Call
Results
HTTP:
GET
HTML
Client

4. Role of Database Server (4 tier)
Results
App.
Server
SQL or
Procedure Call
Proc./
Trans
Call
Results
HTML
HTTP: GET
Client
Web Server

5. Logical Objects

6. Logical Objects Database consists of Schemas own Objects Tables
Indexes
Sequences
Views
Procedures
Triggers
Etc
Objects

7. Schema Types Application Schemas Database consists of User Schemas
Payroll
Student records
Financial Reporting
Nascar
Hollywood
User Schemas
Joe
Fred
Dave
Database
consists of
Schemas
own
Objects
(tables, indexes, etc)

8. Schema Attributes Application Schemas User Schemas
Usually referred to as a “schema object”
Contains a set of closely related tables and associated objects
Typical Object Reference: Hollywood.Movies
User Schemas
Often referred to as a “User” or “Account” object.
May or may not contain personal tables (Joe.Contacts).
May or may not have the right to even create objects.
Are generally granted privileges to objects in application schemas.

9. LAB Create a user schema And an application schema Using dba studio
Note security weakness:
System (pw: manager)
Sys (pw: change_on_install)
Scott (pw: tiger)
Sysman (pw: oem_start)

10. Caution Creating a user schema from SQL:
CREATE USER CALVIN IDENTIFIED by HOBBES

11. LAB Creating a user schema from SQL:
CREATE USER CALVIN IDENTIFIED by HOBBES
DEFAULT TABLESPACE USERS
TEMPORARY TABLESPACE TEMP
QUOTA 100M on users
QUOTA 100M on temp
QUOTA 100M on rbs; quota on RBS not necessary on 9i
GRANT CONNECT TO CALVIN; let him log in
GRANT RESOURCE TO CALVIN; -- let him create tables and other objects

12. Oracle vs. SQL Server Database SQL Server Software Instance defines
consists of
Schemas
Users
own
Databases
own
contain
Objects
(tables, indexes, etc)
Objects
(tables, indexes, etc)

13. Oracle vs. SQL Server Database SQL Server Software Instance defines
consists of
Schemas (users)
Users
own
Databases
contain
Granted
Privileges to
own
Objects
(tables, indexes, etc)
Granted
Privileges to
Objects
(tables, indexes, etc)

14. Controlling Application Access
Each User is given an Oracle Account and control is maintained by granting privileges to tables, procedures and other objects. (e.g. DESIGN)
All users connect ominously to a web site. The Web or Application server connects to Oracle in the context of a particular user.
Although the Web or Application server connects to Oracle in the context of a particular user, individuals connecting to the web site must still authenticate for the interface to determine what they should be allowed to do:
Oracle Authentication
Local “user” table in application
Network authentication

15. Roles and Profiles Role Profile
Functions similar to NT Groups
Specific Object and System Privileges are granted to the Role
That Collection of Privs can be quickly granted to a USER by granting them the Role (Example: GRANT DBA to HOMER)
Profile
Provides default values for USER attributes such as
Number of Concurrent Sessions
Password complexity

16. LAB Creating a role Create ROLE trainee;
Grant connect to trainee; -- right to log on
Grant resource to trainee; -- right to create objects
Grant select_catalog_role to trainee; -- dictionary privs

17. Creating user schemas from PL/SQL:
LAB
Creating user schemas from PL/SQL:
DECLARE
v_sqlstatement varchar2(200);
v_newclass newclass%rowtype;
CURSOR newclass_cursor IS SELECT * from newclass;
BEGIN
DBMS_OUTPUT.PUT_LINE ('****************** begin account creation');
OPEN newclass_cursor;
FETCH newclass_cursor into v_newclass;
WHILE newclass_cursor%found LOOP
DBMS_OUTPUT.PUT_LINE (v_newclass.userid);
v_sqlstatement := 'create user ' || UPPER(v_newclass.userid) || ' identified by oracle ';
v_sqlstatement := v_sqlstatement || 'DEFAULT TABLESPACE USERS ';
v_sqlstatement := v_sqlstatement || 'TEMPORARY TABLESPACE TEMP ';
v_sqlstatement := v_sqlstatement || 'QUOTA 100M on users ';
v_sqlstatement := v_sqlstatement || 'QUOTA 100M on temp ';
v_sqlstatement := v_sqlstatement || 'QUOTA 100M on rbs '; -- rbs quota not needed in 9i
execute immediate v_sqlstatement; -- this is dynamic SQL needed because of early binding
v_sqlstatement := 'GRANT trainee TO ' || v_newclass.userid;
execute immediate v_sqlstatement;
END LOOP;
DBMS_OUTPUT.PUT_LINE ('****************** end account creation');
CLOSE newclass_cursor;
END; /

18. Oracle’s Architecture

19. Instance vs. Database Instance Database (memory structures)
(disk structures)

20. Multiple Instances for 1 Database
Instance A
(memory structures)
Instance B
(memory structures)
Database 1
(disk structures)

21. Multiple Databases for 1 Instance
Instance A
(memory structures)
Database 1
(disk structures)
Database 2
(disk structures)

22. Instance to Instance Communication
Instance A
(memory structures)
Instance B
(memory structures)
Via client
Or replication
process
Database 1
(disk structures)
Database 2
(disk structures)

23. Key structures and Processes
CLIENT
ORACLE INSTANCE
CLIENT
CLIENT
Database Buffer Cache
Redo Log Buffer
Shared Pool
Library
Cache
LSTNR
Network
Data Dictionary
Cache
SERVER
SERVER
SERVER
DBWR
SMON
PMON
CKPT
LGWR
ARCH
Background
Processes
On-line
Redo
Log Files
Data
Files
(Inc. RB
Segments)
Control
Files
On-line
Redo
Log Files
Data
Files
(Inc. RB
Segments)
Control
Files
On-line
Redo
Log Files

24. Database Buffer Cache Number of Buffers determined by
Initialization File Parameter:
DB_BLOCK_BUFFERS (8i)
DB_CACHE_SIZE (9i)
Block Size is a multiple of OS Block.
Block Size if fixed in Oracle 8i.
Block Size is not fixed in 9i except for the system, rollback, and temp tablespaces.
LRU algorithm used to determine buffered data.
DBWR
Data
Files
(Inc. RB
Segments)
Data
Files
(Inc. RB
Segments)
Free block
Used block
Dirty block

25. Buffer Hit Ratio
Consistent Gets + DB Block Gets - Physical Reads
* 100
Consistent Gets + DB Block Gets
Generally, a hit ratio below 80% indicates too many
physical reads and suggests that DB_Block_Buffers
should be increased.

26. Hit Ratio Since Instance Startup
LAB
Hit Ratio Since Instance Startup
Select
sum(decode(NAME, 'consistent gets',VALUE, 0)) "Consistent Gets",
sum(decode(NAME, 'db block gets',VALUE, 0)) "DB Block Gets",
sum(decode(NAME, 'physical reads',VALUE, 0)) "Physical Reads",
round((sum(decode(name, 'consistent gets',value, 0)) +
sum(decode(name, 'db block gets',value, 0)) -
sum(decode(name, 'physical reads',value, 0))) /
(sum(decode(name, 'consistent gets',value, 0)) +
sum(decode(name, 'db block gets',value, 0))) * 100,2) "Hit Ratio"
from v$sysstat
Next: change number of buffers, bounce service, large query, check hits

27. Shared Pool Library Cache Holds parsed SQL statements
Interrogate via v$sqlarea & v$librarycache
CURSOR_SHARING = FORCE
Data Dictionary Cache
Holds table and column definitions
and privileges
Shared Pool
Library
Cache
Data Dictionary
Cache

28. LAB Shared Pool Hit Ratios Library Cache Hit Ratio
Select (sum(pins) / (sum(pins) + sum(reloads))) * 100 “Lib. Hit Ratio”
from v$librarycache
Dictionary Hit Ratio
Select (sum(gets) / (sum(getmisses) + sum(gets))) * 100 “Dict. Hit Ratio”
from v$rowcache
Also look at v$sqlarea

29. Oracle Processes Background Processes Listener Process
run on server
as separate processes on UNIX (ps –ef | grep <ORA_SID>)
As separate threads in single service on NT
Listener Process
one or more per server
listens for connection requests
hands off to server process (on diff. Port)
Server Processes
Run on server
Typically one process to support each connected user (unless MTS)
Client (“User”) Process
runs on client machine
communicates with a server process on server

30. Oracle Background Processes
DBWR
Writes dirty blocks from the buffer pool back to disk.
SMON
Checks for consistency, initiates recovery
PMON
Cleans up resources if process fails
CKPT
Updates database status after commits and other key events.
LGWR
Writes before and after images of changed rows into the on-line redo log files
ARCH
Numbers and archives on-line redo log files

31. LAB Start and stop the instance And listener services using
Various methods

32. LAB Who is logged in? Look at v$session
Alter system kill session ‘sid, serial’;

33. Oracle Commit Processing
Database Buffer Cache
Redo Log Buffer
DB-7F3 FRED
DB-7F4 JANE
Data requested might or
Might not be in the buffer.
DBWR
On-line
Redo
Log File C
Data
Files
(Inc. RB
Segments)
Update Emp
Set Sal = 40000
Where name=‘FRED’
On-line
Redo
Log File B
Data
Files
(Inc. RB
Segments)
On-line
Redo
Log File A

34. Oracle Commit Processing
Database Buffer Cache
Redo Log Buffer
DB-7F3 FRED
DB-7F4 JANE
BEGIN SCN 412
LGWR
May or may not
Have written at this point.
DBWR
On-line
Redo
Log File C
Data
Files
(Inc. RB
Segments)
Update Emp
Set Sal = 40000
Where name=‘FRED’
On-line
Redo
Log File B
Data
Files
(Inc. RB
Segments)
On-line
Redo
Log File A

35. Oracle Commit Processing
Database Buffer Cache
Redo Log Buffer
DB-7F3 FRED
DB-7F4 JANE
RB-65B
BEGIN SCN 412
LGWR
May or may not
Have written at this point.
DBWR
On-line
Redo
Log File C
Data
Files
(Inc. RB
Segments)
Update Emp
Set Sal = 40000
Where name=‘FRED’
On-line
Redo
Log File B
Data
Files
(Inc. RB
Segments)
On-line
Redo
Log File A

36. Oracle Commit Processing
Database Buffer Cache
Redo Log Buffer
DB-7F3 FRED
DB-7F4 JANE
OLD:7F3 FRED 30000
RB-65B NULL
OLD:RB-65B
BEGIN SCN 412
LGWR
May or may not
Have written at this point.
DBWR
On-line
Redo
Log File C
Data
Files
(Inc. RB
Segments)
Update Emp
Set Sal = 40000
Where name=‘FRED’
On-line
Redo
Log File B
Data
Files
(Inc. RB
Segments)
On-line
Redo
Log File A

37. Oracle Commit Processing
Database Buffer Cache
Redo Log Buffer
DB-7F3 FRED
DB-7F4 JANE
NEW:RB-65B FRED 30000
OLD:DB-7F3 FRED 30000
RB-65B FRED 30000
OLD:RB-65B
BEGIN SCN 412
LGWR
May or may not
Have written at this point.
May or may not
Have written at this point.
(rollback segs. First)
DBWR
On-line
Redo
Log File C
Data
Files
(Inc. RB
Segments)
Update Emp
Set Sal = 40000
Where name=‘FRED’
On-line
Redo
Log File B
Data
Files
(Inc. RB
Segments)
On-line
Redo
Log File A

38. Oracle Commit Processing
Database Buffer Cache
Redo Log Buffer
DB-7F3 FRED
NEW:7F3 FRED 40000
DB-7F4 JANE
NEW:RB-65B FRED 30000
OLD:DB-7F3 FRED 30000
RB-65B FRED 30000
OLD:RB-65B
BEGIN SCN 412
LGWR
May or may not
Have written at this point.
May or may not
Have written at this point.
(rollback segs. First)
DBWR
On-line
Redo
Log File C
Data
Files
(Inc. RB
Segments)
Update Emp
Set Sal = 40000
Where name=‘FRED’
On-line
Redo
Log File B
Data
Files
(Inc. RB
Segments)
On-line
Redo
Log File A

39. Oracle Commit Processing
Database Buffer Cache
Redo Log Buffer
DB-7F3 FRED
COMMIT SCN 412
NEW:7F3 FRED 40000
DB-7F4 JANE
NEW:RB-65B FRED 30000
OLD:DB-7F3 FRED 30000
RB-65B FRED 30000
OLD:RB-65B
BEGIN SCN 412
Definitive write
through commit
record
LGWR
May or may not
Have written at this point.
(rollback segs. First)
DBWR
On-line
Redo
Log File C
Data
Files
(Inc. RB
Segments)
Update Emp
Set Sal = 40000
Where name=‘FRED’
On-line
Redo
Log File B
Data
Files
(Inc. RB
Segments)
On-line
Redo
Log File A

40. LAB
Simulate Server
Failure after update
But before commit

41. GO
BACK
Go Back 2 slides
And discuss
“consistent gets”

42. Logical to Physical Mapping (controlling where objects are stored)
Database
Oracle
Tablespace is
similar to
SQL Server
File Group.
Stores objects in
Tablespaces
Made Persistent via
DataFiles

43. Why multiple Tablespaces?
Reduce Disk Contention by spreading disk I/O over multiple spindles.
We control which TS objects are stored on
We control physical location of TS datafiles
Even if all disks are in use currently, the best practice is to keep major apps on different tablespaces to more easily allow for future movement.
Reduce performance degradation during on-line physical backups.
Allows different applications to have different physical parameters
block size
Fragmentation level
etc

44. Typical Tablespaces: SYSTEM 32464 E:\ORACLE\ORADATA\INSY\SYSTEM01.DBF
RBS E:\ORACLE\ORADATA\INSY\RBS01.DBF
USERS E:\ORACLE\ORADATA\INSY\USERS01.DBF
TEMP E:\ORACLE\ORADATA\INSY\TEMP01.DBF
TOOLS E:\ORACLE\ORADATA\INSY\TOOLS01.DBF
INDX E:\ORACLE\ORADATA\INSY\INDX01.DBF
DRSYS E:\ORACLE\ORADATA\INSY\DR01.DBF
OEM_REPOSITORY E:\ORACLE\ORADATA\INSY\OEM_REPOSITORY.ORA

45. Typical OFA segregation
Oracle software
System tablespace
System indexes
RBS tablespace
Data tablespace
Data Indexes TS
Temp tablespace
Tools tablespace inc. index
Online redo log 1
Online redo log 2
Online redo log 3
Control file 1
Control file 2
Control file 3
Application software
User Tablespace inc. indexes
Archive log dest

46. RAID: Redundant Array of Inexpensive Disks
Volume Set:
1 2 3
4 5 6
7 8 9
10 11
12 13
14 15 C:
Stripe Set (Raid Level 0)
1 2 3
4 5 6
7 8 9
10 11
12 13
14 15
16 17
18 19
20 21

47. RAID: Redundant Array of Inexpensive Disks
Mirror set (Raid level 1): =
Drive
Controller

48. RAID: Redundant Array of Inexpensive Disks
Stripe Set with Parity (Raid Level 5) + + = =
parity =
data

49. RAID: Redundant Array of Inexpensive Disks
Stripe Set with Parity (Raid Level 5) + + = =
parity =
data

50. RAID: Redundant Array of Inexpensive Disks
Mirrored Stripe Set (Raid Level 0 + 1)
Data container
1 2 3
4 5 6
7 8 9
10 11
12 13
14 15
16 17
18 19
20 21
Mirror container
1 2 3
4 5 6
7 8 9
10 11
12 13
14 15
16 17
18 19
20 21

51. RAID: Redundant Array of Inexpensive Disks
Stripe Set of Mirrors (Raid Level 1 + 0)
Stripe Set
Mirror Set
Mirror Set
Mirror Set
1 2 3
4 5 6
7 8 9
10 11
12 13
14 15
16 17
18 19
20 21
1 2 3
4 5 6
7 8 9
10 11
12 13
14 15
16 17
18 19
20 21

52. Large Scale RAID dependent Oracle Installation
Cabinet 1 (9 Containers, 42 drives)
Log 1
Ndx 3
Log 2
Ndx 4
Log 3
Intf 1 c1 c3 c2
Data 1, Cntrl 1
Data 2, Cntrl 2
Sys, Rbs, Temp
Cabinet 2 (9 containers, 42 drives)
Log 4
Ndx 1
Log 5
Ndx 2
Log 6
Intf 2 c4 c6 c5
Data 3, Cntrl 3
Data 4, Cntrl 4
Archived Logs
RAID 1 (Log 1)
RAID (Ndx 3)
Controller 1
(c1) Details:
RAID (Data 1, Cntrl 1)
Source: Oracle Performance Tuning 101, Oracle Press

53. Datafiles, INIT, and Control Files
Small Scale RAID dependent Oracle Installation optimized for read/write operations.
Redo
Log Files
Arch
Log Files
Datafiles, INIT, and Control Files
Raid 1
Raid 1
RAID 1 + 0

54. LAB Directly Examine: dba_tables dba_tablespaces V$datafile
Or indirectly:
@\\neelix\oracle\scripts\admin\datafiles
@\\neelix\oracle\scripts\admin\usertabs
Look at Same using DBA studio
Create a new tablespace
And related datafile(s).

55. Creating Indexes and Tables in specific tablespaces.
Each user is assigned a default tablespace.
Don’t create tables when logged in as system or sys unless instructed to do so when installing Oracle tools.
Override defaults when necessary through extended DDL syntax.
CREATE TABLE GLACCOUNTS
( AccountNum char(6)
Name varchar2(30),
Balance number(12,2))
TABLESPACE FINANCIALS;