Introduction to Oracle 2

Introduction to OracleAnton Topurov IT-DB

23 April 2013

Introduction to Oracle 3

What is a database?

23 April 2013

Introduction to Oracle 4

Organized Collection of Data

23 April 2013

Introduction to Oracle 5

IT manager

23 April 2013

Introduction to Oracle 6

App Developer

23 April 2013

Introduction to Oracle 7

Database Administrator

23 April 2013

Introduction to Oracle 8

System Administrator

23 April 2013

Introduction to Oracle 9

IT manager

23 April 2013

Introduction to Oracle 10

What is

23 April 2013

Database?

Introduction to Oracle 1123 April 2013

Introduction to Oracle 12

Introduction to Oracle 13

Ready to find out more?

23 April 2013

Introduction to Oracle 14

Oracle Database Internals

23 April 2013

Introduction to Oracle 1523 April 2013

Oracle Database

Oracle Instance

Real Application Clusters (RAC)

SQL statements processing

Working with Oracle Database

Introduction to Oracle 1623 April 201323 April 2013 Introduction to Oracle 16

Introduction to Oracle 17

Oracle Database Server

23 April 2013

Introduction to Oracle 18

Simplified view

23 April 2013

System Global Area (SGA)

Background Processes

Data Files Control Files Online Redo Logs

Server Processes

PGA

Introduction to Oracle 19

Database Physical Layout

23 April 2013

Data Files Control Files Online Redo Logs

Introduction to Oracle 20

Physical to Logical

23 April 2013

Data Files

Introduction to Oracle 21

Logical Layout

23 April 2013

Block• The smallest

logical unitof data storage

Extent• Continios set of

blocks

Segment• Type (table, index,..)

• Within a tablespace

Tablespace• Maps to one or more

datafiles

Introduction to Oracle 2223 April 2013

Oracle Database

Oracle Instance

Real Application Clusters (RAC)

SQL statements processing

Working with Oracle Database

Introduction to Oracle 23

Oracle Instance

23 April 2013

System Global Area (SGA)

Background Processes

Data Files Control Files Online Redo Logs

Introduction to Oracle 24

SGA contents

23 April 2013

Buffer cache• holds copies of data blocks

• server processes manipulate data from buffer cache (not directly from data files)

• managed using LRU algorithm (Least Recently Used)

Shared pool• shared memory constructs

like shared SQL areas• most recently executed SQL

statements

• most recently used data definitions

Introduction to Oracle 25

Backup

Background Processes

23 April 2013

System Monitor

Process Monitor

Diagnosability Process

Data Files Control Files Online Redo Logs

Database Writer

Archived Redo Logs

Redo Log ArchiverRedo Log WriterCheckpointer

Buffer Cache System Global Area (SGA)Redo Log

Buffer

Introduction to Oracle 2623 April 2013

Oracle Database

Oracle Instance

Real Application Clusters (RAC)

SQL statements processing

Working with Oracle Database

Introduction to Oracle 27

Real Application Clusters

23 April 2013

Data Files Control Files Online Redo Logs

SGA

PGA

SGA

PGA

Clusterware

SGA

PGA

Clusterware

Introduction to Oracle 2823 April 2013

Oracle Database

Oracle Instance

Real Application Clusters (RAC)

SQL statements processing

Working with Oracle Database

Introduction to Oracle 29

Database Account

• Database user • username/password to connect to database

• Privileges• System and object privileges / roles

• CREATE SESSION, CREATE TABLE, CREATE PROCEDURE, CREATE JOB,…

• EXECUTE ON DBMS_LOCK, SELECT ON HR.EMPLOYEES, …

• Profiles• CERN_DEV_PROFILE: 10 concurrent sessions

• CERN_APP_PROFILE: 400 concurrent sessions

• Space quota on tablespaces

23 April 2013

Introduction to Oracle 30

Database vs Schema

A Schema?• Collection of objects• Owned by a database user and has the

same name as that user• Each user owns a single schema.• Good programming practice is to prefix

objects by schema name

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select name from hr.employees where id=7;

Introduction to Oracle 31

Connecting to Oracle Database

23 April 2013

Listenerport 10121

sqlplus username@

’( DESCRIPTION=

(ADDRESS= (PROTOCOL=TCP)

(HOST=node1.cern.ch) (PORT=10121))

(CONNECT_DATA= (SID=DEVDB11)))’

SGA

Instance SID: DEVDB11

PGA

node1

Data Files Control Files Online Redo Logs

Introduction to Oracle 32

node2-v

Connecting to RAC Database

23 April 2013

Data Files Control Files Online Redo Logs

SGA

PGA

sqlplus username@ ( DESCRIPTION=

(ADDRESS= (PROTOCOL=TCP) (HOST=node2-v.cern.ch) (PORT=10121))

(ADDRESS= (PROTOCOL=TCP) (HOST=node1-v.cern.ch) (PORT=10121)) (LOAD_BALANCE=off) (CONNECT_DATA= (SERVER=DEDICATED) (SERVICE_NAME=CERN_SRV1.cern.ch) ))’

Listener

SGA

PGA

Listener

CERN_SRV1CERN_SRV3CERN_SRV2

node1.cern.ch node2.cern.ch

node1-v Clusterware Clusterware

Introduction to Oracle 33

Local naming method

Based on tnsnames.ora

/afs/cern.ch/project/oracle/admin

\\cern.ch\dfs\Applications\Oracle\ADMIN

23 April 2013

( DESCRIPTION=

(ADDRESS= (PROTOCOL=TCP) (HOST=node2-v.cern.ch) (PORT=10121))

(ADDRESS= (PROTOCOL=TCP) (HOST=node1-v.cern.ch) (PORT=10121)) (LOAD_BALANCE=off) (CONNECT_DATA= (SERVER=DEDICATED) (SERVICE_NAME=CERN_SRV1.cern.ch) ))’

cerndb1 =

sqlplus username@

Introduction to Oracle 3423 April 2013

Oracle Database

Oracle Instance

Real Application Clusters (RAC)

SQL statements processing

Working with Oracle Database

Introduction to Oracle 35

SQL Statements Processing

23 April 2013

SQL Statement

Syntax Check

Semantic Check

Shared Pool Check

Optimization

Row Source Generation

Execution

Parsing

Soft Parse

Hard Parse

select * from hr.employees;

select * from hr.employees;sql_id = 8k3hpjw6yjup5

select name from hr.employees where id=:id_val;

Introduction to Oracle 36

Summary

23 April 2013

Introduction to Oracle 37

Documentation• Oracle Database Concepts

http://docs.oracle.com/cd/E11882_01/server.112/e25789/toc.htm

• Oracle 11g documentation• http://www.oracle.com/pls/db112/portal.all_books

• Architecture poster

23 April 2013

Introduction to Oracle 38

Thank you!

23 April 2013