Les 01 core

1Copyright © 2009, Oracle. All rights reserved.

Core Concepts and Tools of the Oracle Database

Copyright © 2009, Oracle. All rights reserved.1 - 2

Objectives

After completing this lesson, you should be able to:• Describe the core concepts of the Oracle Database

architecture with Automatic Storage Management (ASM)• Use configuration and management DBA tools• Describe the technical course environment


Naming the Core Components of an Oracle Database Server

Database (Storage Structures)

Serverprocess

PGA

Userprocess

Instance

Memory Structures (System Global Area)

Process Structures

Client

ServerConnection


Oracle Database Server Architecture Overview

Database (storage structures)

Serverprocess

PGA

Userprocess

Instance

Memory structures (System Global Area)

Process structures

Client

Server

Session

Connection


Instance-Database Configurations

D1

D2

I1

I2I1 I2 I3

D

Clustered systemNonclustered system

Local storage

Shared storage


Naming the Memory Structures of an Oracle Database

Assign these names:

Shared pool

Databasebuffercache

Streams pool

Large pool

Java pool

Stack

Space

KEEP buffer poolRecycle

buffer poolnK buffer

cache

User

Global

Area

Server process

Redo logbuffer

Program Global Area (PGA)

System Global Area (SGA)


Oracle Database Memory Structures

Serverprocess 1

Shared poolDatabase

buffercache

Redo logbuffer

Streams poolLarge pool Java pool

Stack

Space


Program Global Area (PGA)

Serverprocess 2

KEEP buffer pool

Recycle buffer pool

nK buffer cache

User

Global

Area

Stack

Space

User

Global

Area

PGA


Process Architecture

• User process– Is the application or tool that connects to the Oracle

Database• Database processes

– Server process: Connects to the Oracle instance and is started when a user establishes a session

– Background processes: Are started when an Oracle instance is started

• Daemon/Application processes– Networking listeners– Grid Infrastructure daemons


Process Structures

PMONSMON

Others

Instances (ASM and Database separate)

RECO

ARCn

DBWn LGWRCKPT

PGA

Userprocess

Serverprocess

Background processes


Required:

ASMB RBALOptional:Listener

Grid Infrastructure Processes(ASM and Oracle Restart)

orarootagent

ohasd ocssd diskmon

oraagent cssdagent


Adding Process Names

1. The ______process writes the dirty buffers to the data files.

2. The ______process writes the redo entries to the online redo log files.

3. The ______process writes checkpoint information in the control file and each data file header.

4. The ______process performs recovery on instance startup.

5. The ______process performs process recovery when a user process fails.

6. The ______process resolves in-doubt distributed transactions.

7. The ______processes copy redo log files to a designated storage device.

A. Checkpoint process (CKPT)

B. System monitor process (SMON)

C. Recoverer process (RECO)

D. Log writer process (LGWR)

E. Archiver processes (ARCn)

F. Process monitor process (PMON)

G. Database writer process (DBWn)


• Oracle Grid Infrastructure is started by the OS init daemon.

• Oracle Grid Infrastructure installation modifies the /etc/inittab file to ensure startup every time the machine is started in the corresponding run level.

Process Startup Sequence

init.ohasd (root)

ohasd.binoraagent.binorarootagent.bindiskmon.bincssdagentocssd.bin

init

Grid InfrastructureWrapper Script

Grid InfrastructureDaemons and Processes

Operating SystemInit Daemon

# cat /etc/inittab..h1:35:respawn:/etc/init.d/init.ohasd run >/dev/null 2>&1 </dev/null

ASM instance Listener DB instance User-defined applications


Database Storage Architecture

Online redo log files

Password file

Parameter file Archived redo log files

Control files Data files

Alert log and trace files

Backup files


Logical and Physical Database Structures

Database

Logical Physical

Tablespace Data file

Segment

Extent

Oracle datablock

Storage system

• SAN

• NAS

• Exadata

• File system

• NFS

• ASM

• RAW


Automatic Storage Management

• Is a portable and high-performancecluster file system

• Manages Oracle database files• Manages application files with ASM Cluster File System (ACFS)• Spreads data across disks

to balance load• Mirrors data in case of failures• Solves storage-management

challenges

ASM Cluster File

System

ASM Dynamic VolumeManager

ApplicationOracle

Database

Operating system

ASM Files for Oracle

Database

Automatic Storage Management


ASM Storage Components

OracleDatabaseData file

ASMdisk group

ASM disk

ASM file

ASMextent

File systemor

Raw device

ASM

ASM allocationUnit


ASM Instance

The ASM Instance is the process and memory components for ASM.

Other misc. processes

System Global Area (SGA) – memory

Sharedpool

Largepool

ASMcache

Freememory

Processes – CPU components

ASM instance

RBAL ARBn GMON Onnn PZ9n

MARK


DBA Configuration Tools

Setting up the technical environment for this course included the following tasks and tools:• Installing and configuring the Oracle Grid Infrastructure for

a stand-alone server with the OUI, including:– Configuring a listener– Creating an ASM instance (+ASM) and configuring the

+DATA disk group– Configuring Oracle Restart

• Creating and configuring additional ASM disk groups (such as +FRA) with asmca

• Installing the Oracle Database 11g software with OUI• Creating the orcl Oracle database with dbcaNote: These tasks have already been performed for you.


Management Framework and Related DBA Tools

The Oracle database management framework includes:• Database instance • Listener• Management interface:

– Management agent (when using Grid Control)

– Database Control

Related tools and commands include:SQL*Plus:

Listener Control utility:

Enterprise Manager Control utility:$ emctl status dbconsole$ emctl start dbconsole$ emctl stop dbconsole

$ lsnrctl status

SQL> startupSQL> shutdown immediate


Facilitating Database Management with Oracle Restart

• Restarting Oracle components when the host computer restarts or after hardware or software failure

• Monitoring components and restarting them, if needed• For single-instance environments• Considering component dependencies:

– Mounting disk groups and starting the ASM instance before starting the database instance

– Soft dependency between the database instance and the listener

• Starting Oracle Restart with the crsctl utility • Managing Oracle Restart components with the srvctl

utility $ srvctl stop database –d orcl –o abort


Quiz

Oracle Restart is installed and configured as part of an Oracle Grid Infrastructure for stand-alone server installation.1. True2. False


Summary

In this lesson, you should have learned how to:• Describe the core concepts of the Oracle Database

architecture with ASM• Determine which DBA configuration and management

tools to use for which task• Describe the technical course environment

orcl +asm

DATAFRA

Enterprise ManagerCommand line

Technology

Les 01 core