Session 01 Oracle PLSQL Architecture

7/25/2019 Session 01 Oracle PLSQL Architecture

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Overview

Oracle 10G

LEVEL LEARNER


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Questions

Coding

Standards

2

Reference

Test Your

Understanding

Icon Used

Lend A

Hand

Hands on !ercise "oints To"onder

Su##ar

$

O%er%ie& O'(ecti%e C)ec* YourUnderstandi


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O%er%ie&

T)e session +ro%ides insig)t to&ards

O%er%ie&, ")$sical and Logical

-ata'ase Structures, A++licationArc)itecture, -ata'ase Securit$ and

Utilities of Oracle.

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O'(ecti%e

After co#+leting t)is session, +artici+ants

&ill 'e a'le to

Overview about Oracle.

Oracle's Physical and Logical Database

Structures.

Oracle Application Architecture.

How Oracle Works

Oracle !e"ory Architecture

Oracle Process Architecture

Oracle Database Security

Overview o# PL$S%L


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Oracle-ata'aseO%er%ie&

Oracle is an Relational Database Management Systemde%elo+ed'$ Oracle Cor+oration.

&T)e Oracle -ata'ase is co##onl$ referred to as OracleRDBMS .

&Oracle &as t)e 3rst data'ase +roduct to run on a %ariet$ of+latfor#s fro# #icro to #ainfra#e.

&An Oracle data'ase are #ade u+ of 3les na#el$ data ands$ste# 3les.

&A single Oracle Ser%er installation can )a%e one or #oredata'ase.


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Oracle-ata'aseandOracleInstance

very running database is associated with its own Oracle

instance.

When the database is started Oracle allocates a "e"ory areacalled SGA(Syste" Global Area) and starts "any oracle

process to "anage the database. *he co"bination o#

Oracle Process and S+A is called ,Oracle Instance-

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-ata'ase

Oracle data'ase is associated&it) an oracle instance

Oracle Instance

d d l


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Database Server CHN1234

UnderstandOracleInstancewith an!a#+le

Assu"e a ad"inistrator installs three databases in a database server (CHN1234) #or

three applications.& Banking application - anking

& Retail application - /etail

& Media application - !edia

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6an*ing

-ata'ase

Oracle 0nstance

Retail

-ata'ase

Oracle 0nstance

7edia

-ata'ase

Oracle 0nstance

8)en eac) data'ase isstarted an oracle instance&ill 'e started andassociated to t)e res+ecti%edata'ases.

So eac) data'ase &ill )a%e its o&n instance

created.


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Oracledata'asestructures

9

Oracle -ata'ase structure )as t&o classi3cations,

Logical Database

Structure

Physical Database

Structure

Oracle Database

Structure

Oracle logically divides the database

into s"aller units to "anage1 store1and retrieve data e##iciently.

Oracle database physically "aintains

data in one or "ore physical #ilesgrouped under physical data structure.


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Logical-ataStructure

T)e logical data structure includes t)e follo&ing,

:


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")$sical-ataStructure

T)e +)$sical data structure includes t)e follo&ing3les,

Oracle uses t)ese 3les for +)$sicall$ storing t)edata'ase data.10


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Accessingt)e-ata'ase

11

T)e data fro# t)e Oracle -ata'ase can 'e accessed, #odi3ed and re#o%ed'$ using SQL ;Structured Quer$ Language< &it) t)e )el+ of se%eral tools.

So#e of t)e tools &)ic) are co##onl$ used are

1. Oracle SQL="lus and iSQL="lus

2. T)ird>+art$ tools.

-ata'aseT)e SQL &ill 'e sent o%er TC"?I".

T)e SQL de%elo+edin client #ac)ine

T)e SQL e!ecutedin

T)e data'aseser%er.

T)e data retrie%ed is returned to t)eclient.


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OracleSQL="lusandiSQL="lus

12

SQL="lus

& SQL = "lus is a tool for accessing, u+dating and re#o%ing data

fro# Oracle -ata'ase.

& SQL = "lus is a co##and line tool &)ic) are used for e!ecuting SQL

@ueries.

iSQL*Plus:

& iSQL="lus is a 'ro&ser>'ased interface for accessing, u+dating and

re#o%ing data fro# Oracle -ata'ase.

& iSQL="lus ena'les $ou to use a &e' 'ro&ser to connect to Oracle

-ata'ase and +erfor# t)e sa#e actions as t)e co##and line

SQL="lus .


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SQL="lusToolscreens)ot

1/

SQL = "lus Login Screen

SQL = "lus ditor screen e!ecuting SQLs


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OracleiSQL="lusToolScreenS)ot

1

Accessing Oracle -ata'ase t)roug) iSQL="LUS tool


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8)atisinsideaOracleInstanceB

1

Oracle Instance internall$ )as t&o #a(or co#+onents for #anagingt)e data'ase,

&7e#or$ Structure&"rocess Structure

Memory structure refers to )o& t)e #e#or$ of t)e oracle data'aseis organied to ensure t)e #anage#ent of data'ase.

Process structure refers to t)e +rocesses running inside oracle#e#or$ for #anaging t)e functioning of data'ase.


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InsideanOracleInstance

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Oracle Instance

SGA

Da%a"ool

Large"ool

6uEerCac)e

Redo Log6uEer

S)ared"ool

Ser%er"rocess 1

"GA

Ser%er"rocess 2

"GA "7OF "GA

6ac*ground "rocess

"GA


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Oracle7e#or$structure

Oracle Memory Structure uses:

& Oracle creates and uses #e#or$ structures toco#+lete se%eral (o's.

& 7e#or$ stores +rogra# code 'eing run and datas)ared a#ong users.

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S$ste#Glo'alArea

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&T)e S$ste# Glo'al Area ;SGA< is a s)ared #e#or$ region t)atcontains data and control infor#ation for one Oracle instance.

&Oracle allocates t)e SGA &)en an instance starts anddeallocates it &)en t)e instance s)uts do&n.

&ac) instance )as its o&n SGA.

&All users currentl$ connected to an Oracle ser%er s)are t)edata in t)e SGA. So t)is is also referred as Shared Global Area.

&T)e SGAs +ur+ose is to s+eed u+ @uer$ +erfor#ance and toena'le a )ig) a#ount of concurrent data'ase acti%it$.


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S$ste#Glo'alArea

1:

S)ared Glo'al Area )as se%eral #e#or$ structures ,

SGA6uEerCac)e

Redo Log6uEer

S)ared"ool

T)e -ata'ase 'uEercac)e cac)es t)edata'ase data.

T)e redo log 'uEerstores redo entries,

a log of c)anges #adeto t)e data'ase.

Used to store #ostrecentl$ e!ecuted

SQL?"LSQLState#ents and data-e3nitions, li*e ta'le,

%ie&s etc.


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"rogra#Glo'alArea

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&T)e "GA is t)e area in t)e #e#or$ t)at contains t)e data and controlinfor#ation for one ser%er +rocess.

&ac) ser%er +rocess &ill )a%e its o&n "GA.

&A ser%er +rocess is started &)en a user logs into t)e data'ase toaccess it.&A ser%er +rocess is tagged to one or #ore user +rocess 'ased on

con3guration.

&"GA is allocated &)en a ser%er +rocess is created and deallocated

&)en t)e ser%er +rocess is ter#inated.

&"GA is not s)ara'le and used '$ onl$ one ser%er +rocess.

&T)e "GA is used to +rocess SQL state#ents 3red '$ users and to )oldlogon and ot)er session infor#ation.

&"GA can 'e d$na#icall$ resied.


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Oracle"rocessarc)itecture

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Aprocessis a t)read of control or a #ec)anis# in an o+erating s$ste#t)at can run a series of tas*s. A +rocess nor#all$ )as its o&n +ri%ate#e#or$ area in &)ic) it runs.

!a#+le Ti# a user connect to data'ase to e!ecuted a @uer$ and retrie%e

data. A +rocess &ill 'e created to )andle t)e user re@uest of connecting todata'ase and e!ecuting t)e @uer$. Here, connection establishment andquery eecutionare referred to as tas*s of t)e +rocess.

Ti#

-ata'ase

Connects to data'ase

!ecute SQL

*he process per#or"s the

tasks o# *i" na"ely1&2onnect to database.

&3ecute S%L.

"rocess Created and runsin data'ase ser%er


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"rocessT$+es

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Oracle processesare invoked by user

processes to per#or" #unctions on

behal# o# the invoking process.

Oracle creates a user process to run

the user's application

3a"ple4 5ser process created #or a

6ava progra" which tries to connectto database (or) a user tries to

connect to the database using S%L7

plus.


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"rocessIllustration

2/

Oracle Instance

SGA

Ser%er

"rocess

Reco%er

er

Ti# User"rocess

Ron User"rocess

Dac* User"rocess

"rocess

7onitor

S$ste#

7onitor

-ata'a

se8riter

Log

8riter

Arc)i%

er

Assu#e Ron, !im and "ac# )a%e connected to data'ase and @ueries t)edata'ase.

Oracle "rocesses

User "rocess created foreac) user login.


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8)atis-ata'aseSecurit$?

Oracle data'ase securit$ refers to t)e features t)at control )o&a data'ase is accessed and used.

&"re%ent unaut)oried data'ase access

&"re%ent unaut)oried access to sc)e#a o'(ects

&Audit user actions


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T$+esOf-ata'aseSecurit$.

*his is a "echanis"s that controls the

access and use o# the database at the

syste" level.

3a"ple4&5sing userna"e$password #or D login.

&Si8e o# disk space allocated to a user's

sche"a ob9ects.

*his is a "echanis"s that controls the

access and use o# the database at the

sche"a ob9ect level.

3a"ple4

&y giving access #or users to tables and

other sche"a ob9ects.

&Auditing users access to sche"a

ob9ects.

&ncrypting data to prevent unauthori8ed

access.


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Securit$7ec)anis#s

& Oracle database provides discretionary access control1 which

is a "eans o# restricting access to in#or"ation based on

privileges.

& Appropriate privilege should be assigned to users to access

sche"a ob9ects.

Example: Tomcan be given privilege to access Employeetable

but Roncan:t access it.

& Privileged users can grant other users privileges at their

discretion. ;or this reason it is re#erred as discretionary.

Example: Tomcan give privilege access #or Ronto access

Employee table.

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Securit$7ec)anis#s

Oracle "anages security using the #ollowing "echanis"s

& Database 5sers < Sche"as.

& Privileges

& /oles& Storage settings < %uotas

& Pro#iles< /esource Li"its.

& 5ser authentication

& 5ser Authori8ation

& Auditing

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8)atareOracle-ata'aseUtilities?

Oracle database utilities are tools supplied as part o# the

Oracle So#tware and need not have to be purchased or

downloaded separately.

*hey are used #or1

& Data access and "aintenance.

& Data Loading.

& Database ad"inistration

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Oracle-ata'aseUtilities

2:

5sed #or high=speed

"ove"ent o# data and

dictionary data #ro" one

database to another.

5sed #or >uerying redo

log #iles through a S%L

inter#ace.

5sed #or loading

database with data #ro"

#lat #iles. *he description

o# the data #ile will bestored in a control #ile.


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Introductionto"L?SQL

What is PL/SQL

"L stands for "rocedural LanguageJ and "L?SQL is t)e+rocedural e!tension to SQL &it) design features of an$+rogra##ing language.

!ew "etails a#out PL/SQL:

&"L?SQL allo&s to #i! SQL state#ents &it) "roceduralState#ents li*e IK state#ent, Loo+ing structures etc.

&"L?SQL allo&s --L,-7L,-QL,TCL and -CL State#ents of

SQL to 'e +art of t)e 'loc* structured unit of codes #a*ing"L?SQL a +o&erful transaction +rocessing language.

/0

--L-7L-QLLoo+s, IK etc.

"L?SQLCan Contain


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Introductionto"L?SQL(Cont)

& "L?SQL e!tends SQL '$ adding constructs found in ot)er+rocedural languages li*e

1. -e3ning %aria'les and t$+es

2. Using control structures ;IK>THF>LS

Documents

Session 01 Oracle PLSQL Architecture