This ppt helps people who would like to present their industrial training presentation on Oracle 11g DBA.
This one includes all the operations that dba has to be perform and some other internal concepts of Oracle.
3. Advanced Databases
Objectives
• Define database administration.
• Understand database administration tasks.
• Perform database administration tasks
using Oracle 11g Enterprise Manager.
• Understand Oracle 11g and SQL Server
data storage structures.
3
4. Advanced Databases
What is Database
Administration?
• A Function information technology (IT)
department
• Database Administrator (DBA)
– Overall health / Performance
– Manages Security
– Setup Test and Dev. Environments
• http://www.bls.gov/ooh/computer-and-
information-technology/database-
administrators.htm
4
5. Advanced Databases
Duties of the DBA
• Manage Database Objects – Tables /
Views / Procedures
• Database performance
• Security – Logons /Users / Roles
• Clone data from Production to
Development or Test
• Manage backups and carry out DR plans.
Guide to Oracle 10g
5
10. Advanced Databases
Creating an Administrative
Connection
• Shutting down database makes database
unavailable for user connections
• DBA must log onto database using
administrative connection
• SYS user account
Guide to Oracle 10g
10
11. Advanced Databases
Using OEM to Shut Down and Start
a Database Instance
• DBA shuts down database instance using
Normal, Transactional, or Immediate
shutdown option
– Shutdown process performs five following
tasks:
• Writes contents of data buffer cache to datafiles
• Writes contents of redo log buffer to redo log files
• Closes all files
• Stops all background processes
• Deallocates SGA in server’s main memory
11
12. Advanced Databases
Instance Options
Startup
• Start in one of two
modes:
– Unrestricted
– Restricted
– Mount(data file recovery)
– No mount(control file)
– Open
Shutdown
• Specify one of four ways
to handle existing user
connections:
– Normal
– Immediate
– Abort
12
14. Advanced Databases
Oracle Architecture
• database vs. instance
Parameter files*
Control files**
Data files
Redo Log files
System Global Area (SGA)
Background Processes
Disk Memory
Database Instance
Spfiles, control files,→ BINARY FILES
Pfiles → TEXT FILES
Data files → Database physical files stored on disk
Redo log files → Any changes that are made in database
16. Advanced Databases
Oracle Enterprise Manager
• User account must have DBA role
• Oracle Enterprise Manager (OEM)
– Three-tier architecture
– Console
• Oracle Management Server (OMS)
– Interacts with repository
– Makes it easier for DBAs to administer
multiple databases in organization’s network
16
21. Advanced Databases
Managing Oracle 11g Data Storage
• Like most DBMS’s the logical structures
– Tables
– Constraints
– Views / Procedures
• Can be stored in physical data structures
– Files on disk
– Dedicated drive partitions
– RAM Guide to Oracle 10g
21
22. Advanced Databases
Oracle 11g Data Structures
• Tablespace
– One or more Data Files
• Segment
– Partitioned Data
• Extent
– Growth rule for segment
• Data block
– Database storage data
block
– Operating system blocks
22
23. Advanced Databases
Tablespaces
• One or more Data files
• Stores all database structures + data
– Tables, data, views, sp’s etc…
Guide to Oracle 10g
23
24. Advanced Databases
Datafiles
• .dbf extensions
• Store tablespace contents
• Stored in Oracle_BaseoradataSID
• Use OEM to view and modify
• Grow via Extents
Guide to Oracle 10g
24
26. Advanced Databases
Extents – Smallest unit added to data file
• Sequence of Data Blocks
• When an insert grows beyond the data file
size allocation, a new extent is added.
• More efficient to add groups of data blocks
vs. individual blocks.
Guide to Oracle 10g
26
30. Advanced Databases
Parameter File
• Text file
• Specifies configuration information about
Oracle 10g database instance
• init.ora
– Stored in Oracle_BaseadminSIDpfile folder
• DBAs can edit parameter file
– Modify database configuration
Guide to Oracle 10g
30
31. Advanced Databases
Control Files
• Store information about database structure
and state
• Stored in Oracle_BaseoradataSID
• Three separate control files by default:
– CONTROL01.CTL
– CONTROL02.CTL
– CONTROL03.CTL
– All contain same data
– At least one must be present
31
32. Advanced Databases
Redo Log Files
• Records information to undo action query
changes
• .log extension
• Stored in Oracle_BaseORADATASID
• Pre-image
• Rollback segment
Guide to Oracle 10g
32
34. Advanced Databases
Creating and Managing User
Accounts
• Create new user account
– General information about user account
– System privileges user has in database
– User’s tablespace quota on database server
–Demo!
Guide to Oracle 10g
34
35. Advanced Databases
Specifying General User
Information
• Use OEM
– General page:
• Name
• Profile
• Authentication
• Default tablespace
• Temporary tablespace
• Status
Guide to Oracle 10g
35
36. Advanced Databases
Specifying System Privileges
• System privilege
• Object privilege
• Enable new user to interact with Oracle
11g database
– DBA grants system privileges
– Use System Privileges page in Create User
page
• Admin OptionGuide to Oracle 10g
36
37. Advanced Databases
Types of privileges
System Privileges Object Privileges
(Action on database) (Action on database objects)
Create, create session, drop, Alter, delete, execute,
Update, rename, Index, insert,
Select…….200 distinct privileges. References……..11 distinct privileges.
Guide to Oracle 10g
37
38. Advanced Databases
Tablespace Quotas
• Specifies amount of disk space that user’s
database objects can occupy in default
tablespace
• Must be assigned
• Quota Size value:
– None, default
– Unlimited
– Value Guide to Oracle 10g
38
39. Advanced Databases
Editing Existing User Accounts
• Use OEM
– Select user account to be modified on Users
page
– General page opens
– Select other links to modify properties
Guide to Oracle 10g
39
40. Advanced Databases
Roles
• Database object
• Represents collection of system privileges
• Assign to multiple users
• Create role
– Can inherit privileges from other roles
• Grant Role to User Account
• Easier than manually assigning everything
manually.
40
41. Advanced Databases
Analyze CPU
• Auditing is expensive; we need biggest
bang for the buck - Session Auditing
SQL> audit session;
• Purpose:
– Calculate CPU consumption and profile users
– Calculate I/O used by users
– Identify if someone’s account was locked after
repeated wrong passwords
41
42. Advanced Databases
Understand the CPU Usage
select username, to_char(logoff_time,'mm/dd') ts,
count(1) cnt,
sum(session_cpu) sum_cpu,
avg(session_cpu) avg_cpu,
min(session_cpu) min_cpu,
max(session_cpu) max_cpu
from dba_audit_trail
where logoff_time between '&start_date' and '&end_date'
group by username, to_char(logoff_time,'mm/dd')
order by username, to_char(logoff_time,'mm/dd')
Output
USERNAME TS CNT SUM_CPU AVG_CPU MIN_CPU MAX_CPU
--------------- ----- -------- ------------ ------------ ------------ ------------
USER1 04/04 3 918 306 17 859
USER2 04/04 36 15,286 425 0 4,094
USER3 04/04 3 794 265 174 379
USER4 04/04 187 396,299 2,119 1 124,274
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43. Advanced Databases
The Oracle Data
Dictionary
• Collection of tables and views that show the inner
workings and structure of the db
• “static” data dictionary views
– owned by SYS
– created by catalog.sql script at db creation
– contain DDL info
• dynamic data dictionary views
– also referred to as V$ views
– based on virtual tables (X$ tables)
– provide info about the instance
43
44. Advanced Databases
Some more activities of DBA’s
• Sqlloader→ loading text or .csv files to the
database.
• Table compression→ compressing table size.
• Import/export→ type of backups and
recovery for small business.
• Database transport→ transporting database
from one system to another system.
• Backups and recovery
• Scheduling→ scheduling any repeating
process.
44
46. Advanced Databases
SQL
Advisor
High-load
SQL
IO / CPU
issues
RAC issues
Automatic Diagnostic Engine
Snapshots in
Automatic Workload
Repository
Self-Diagnostic Engine
System
Resource
Advice
Network + DB
config Advice
• Top Down Analysis Using AWR
Snapshots
• Classification Tree - based on
decades of Oracle tuning expertise
• Identifies main performance
bottlenecks using time based
analysis
• Pinpoints root cause
• Recommend solutions or next step
• Reports non-problem areas
– E.g. I/O is not a problem
How Does ADDM Work?
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