Seminar Report - Teradata is a Relational Database Managemen

8/13/2019 Seminar Report - Teradata is a Relational Database Managemen

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1. INTRODUCTION

Teradata is a relational database management system (RDBMS) that drives a

company's data warehouse. Teradata provides the oundation to give a company the power

to grow! to compete in today's dynamic mar"etplace! to achieve the goal o #Transorming

Transactions into Relationships# and to evolve the business by getting answers to a new

generation o $uestions. Teradata's scalability allows the system to grow as the business

grows! rom gigabytes to terabytes and beyond. Teradata's uni$ue technology has been

proven at customer sites across industries and around the world.

Teradata is an open system! compliant with %&S standards. t is currently

available on & M*+R%S and ,indows - operating systems. Teradata is a large

database server that accommodates multiple client applications ma"ing in$uiries against it

concurrently. /arious client platorms access the database through a T0*+* connection

across an BM mainrame channel connection. The ability to manage large amounts o data

is accomplished using the concept o parallelism! wherein many individual processors

perorm smaller tas"s concurrently to accomplish an operation against a huge repository o

data. To date! only parallel architectures can handle databases o this si1e.

2. What is Teradata ?

Teradata is a relational database management system initially created by

the irm with the same name! ounded in 2343. Teradata is part o the &0R 0orporation

which ac$uired the Teradata company on 5ebruary -6! 2332. t is a massively parallel

processing system running a shared nothing architecture. The main point with the

Teradata DBMS is that it's linearly and predictably scalable in all dimensions o a

database system wor"load (data volume! breadth! number o users! comple7ity o

$ueries)! e7plaining its popularity or enterprise data warehousing applications.

Teradata is oered on ntel servers interconnected by the B8&9T messaging abric.

Teradata systems are oered with either 9ngenio or 9M0 dis" arrays or database

storage.

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Teradata offers a choice of several operating systes

&0R & S/R: M*+R%S! a variant o System / & rom %T;T

Microsot ,indows - and ,indows Server -< SS9 =inu7 on >:+bit ntel

servers has been pre+announced or ->. Teradata 9nterprise Data ,arehouses are

oten accessed via ?DB0 or @DB0 by applications running on operating system such as

Microsot ,indows or lavors o &. The warehouse typically sources data rom

operational systems via a combination o batch and tric"le loads.

The largest and most prominent customer o this DBMS is ,al+Mart!

which runs its central inventory and other inancial systems on Teradata. ,al+Mart's

Teradata Data ,arehouse is generally regarded by the DBS industry as being the

largest data warehouse in the world. ?ther Teradata customers include companies li"e

%T;T (ormerly SB0)! Dell! 0ontinental %irlines! &ational %ustralia Ban"! 5ed97!

/odaone! Aap nc! Saeway nc! eBay and aiser *ermanente.

Teradata's main competitors are other high+end solutions such as ?racle

and BM's DB-.

!. Why Teradata?

Teradata is the world's leading 9nterprise Data ,arehousing solutions

provider . Today! more than >C o the world's most admired global companies use

Teradata technology! including

3C o the Top Alobal Telecommunications 0ompanies

EC o the Top Alobal Retailers

4C o the Top Alobal %irlines

>C o the Top Alobal Transportation =ogistics 0ompanies :C o the Top Alobal 0ommercial and Savings Ban"s

%long with our proven! time+tested leadership in data warehousing! Teradata

oers a wide variety o solutions or 0ustomer Relationship Management! Supply and

Demand 0hain Management! 5inancial Services! 9nterprise Ris" Management and much

more. %dd accolades and awards rom Aartner! ntelligent 9nterprise! DM Review and

many other industry e7perts! and Teradata is clearly the best choice.

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". #dvantages $ Disadvantages

#dvantages

2) Teradata data%ase is &inearly scala%le ',e can e7pand the database capacity by Fust

adding more nodes to the e7isting database. the data volume grows we can add more

hardware and e7pand the database capacity.

-) ()tensive parallel processing 'Teradata has a e7tensive parallel processing capacity! it

can handle multiple adhoc re$uests and many concurrent users.


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,. *cala%ility

-ig+re ' 1 *cala%ility

#=inear scalability# means that as you add components to the system! the

perormance increase is linear. %dding components allows the system to accommodate

increased wor"load without decreased throughput. Teradata was the irst commercialdatabase system to scale to and support a trillion bytes o data. The origin o the name

Teradata is #tera+!# which is derived rom Aree" and means #trillion.#

The chart below lists the meaning o the prei7es

refi) ()ponent /eaning

"ilo+ 2 2!! (million)giga+ 23 2!!! (billion)

tera' 1012 1000000000000 trillion3

peta+ 22E 2!!!!! ($uadrillion)

e7a+ 226 2!!!!!! ($uintillion)

Table 2

Teradata can scale rom 2 gigabytes to over 2 terabytes o data on a

single system without losing any perormance capability. Teradata's scalability provides

investent protectionor customer's growth and application development. Teradata is the

only database that is tr+ly scala%le! and this e7tends to data loading with the use o parallel

loading utilities. Teradata is scalable in multiple ways! including hardware! comple7ity! and

concurrent users.

4ard5are

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Arowth is a undamental goal o business. % Teradata M** system easily

accommodates that growth whenever it happens. The Teradata Database runs on highly

optimi1ed &0R servers in the ollowing conigurations

*/ + Symmetric multiprocessing platorms manage gigabytes o data to support an

entry+level data warehousing system.

/ + Massively parallel processing systems can manage hundreds o terabytes o

data. 8ou can start small with a couple o nodes! and later e7pand the system as

your business grows.

,ith Teradata! you can increase the si1e o your system without replacing

Data%ases ',hen you e7pand your system! the data is automatically redistributed

through the reconiguration process! without manual interventions such as sorting!

unloading and reloading! or partitioning.

latfors ' Teradata's modular structure allows you to add components to your

e7isting system.

Data odel ' The physical and logical data models remain the same regardless o

data volume.

#pplications

%pplications you develop or Teradata conigurations will continue to wor"

as the system grows! protecting your investment in application development

Cople)ity

Teradata is adept at comple7 data models that satisy the inormation needs

throughout an enterprise. Teradata eiciently processes increasingly sophisticated business

$uestions as users reali1e the value o the answers they are getting. t has the ability to

perorm large aggregations during $uery run time and can perorm up to >: Foins in a single

$uery.

Conc+rrent Users

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%s is proven in every benchmar" Teradata perorms! Teradata can handle the

most concurrent users! who are oten running +ltiple cople) 6+eries. Teradata has the

proven ability to handle rom hundreds to thousands o users on the system simultaneously.

%dding many concurrent users typically reduces system perormance. Iowever! adding

more components can enable the system to accommodate the new users with e$ual or evenbetter perormance.

7. Teradata /anagea%ility

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?ne o the "ey beneits o Teradata is its manageability. The list o tas"s that

Teradata Database %dministrators do not have to do is long! and illustrates why the

Teradata system is so easy to manage and maintain compared to other databases.

Things Teradata Data%ase #dinistrators Never 4ave to Do

Teradata DB%s never have to do the ollowing tas"s

Reorgani1e data or inde7 space.

*re+allocate tableJinde7 space and ormat partitioning. ,hile it is possible to have

partitioned inde7es in Teradata! they are not re$uired.

*re+prepare data or loading (convert! sort! split! etc.).

nloadJreload data spaces due to e7pansion. ,ith Teradata! the data can beredistributed on the larger coniguration with no oloading and reloading re$uired.

,rite or run programs to split input source iles into partitions or loading.

,ith Teradata! the wor"load or creating a table o 2 rows is the same as

creating a table with 2!!! rows. Teradata DB%s "now that i data doubles! the

system can e7pand easily to accommodate it. Teradata provides huge cost advantages!

especially when it comes to staing Database %dministrators. 0ustomers tell us that their

DB% sta re$uirements or administering non+Teradata databases are three to 2 times

higher.

4o5 Other Data%ases *tore Ro5s and /anage Data

9ven data distribution is not easy or most databases to do. Many databases

use range distri%+tion! which creates intensive maintenance tas"s or the DB%. ?thers

may use inde)esas a way to select a small amount o data to return the answer to a $uery.

They use them to avoid accessing the underlying tables i possible. The assumption is that

the inde7 will be smaller than the tables so they will ta"e less time to read. Because they

scan inde7es and use only part o the data in the inde7 to search or answers to a $uery! they

can carry e7tra data in the inde7es! duplicating data in the tables. This way they do not have

to read the table at all in some cases. %s you will see! this is not nearly as eicient as

Teradata's method o data storage and access.

?ther DB%s have to as" themselves $uestions li"e Iow should partition the dataK

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Iow large should ma"e the partitionsK

,here do have data contentionK

Iow are the users accessing the dataK

Many other databases re$uire the DB%s to an+ally partition the data.

They might place an entire table in a single partition. The disadvantage o this approach is it

creates a bottlenec" or all $ueries against that data. t is not the most eicient way to either

store or access data rows.

,ith other databases! adding! updating and deleting data aects manual data

distribution schemes thereby reducing $uery perormance and re$uiring reorgani1ation. %

Teradatasystem provides high perormance because it distributes the data evenly across

the %M*s or parallel processing. No partitioning or data re'organi8ations are needed.

,ith Teradata! your DB% can spend more time with users developing strategic applications

to beat your competition

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9. Unconditional arallelis

-ig+re '2 Unconditional arallelis

Teradata provides e7ceptional perormance using parallelism to achieve a

single answer aster than a non+parallel system. *arallelism uses multiple processors

wor"ing together to accomplish a tas" $uic"ly.

%n e7ample o parallelism can be seen at an amusement par"! as guests stand

in line or an attraction such as a roller coaster. %s the line approaches the boarding

platorm! it typically will split into multiple! parallel lines. That way! groups o people can

step into their seats simultaneously. The line moves aster than i the guests step onto the

attraction one at a time. %t the biggest amusement par"s! the parallel loading o the rides

becomes essential to their successul operation.

*arallelism is evident throughout a Teradata system! rom the architecture to

data loading to comple7 re$uest processing. Teradata processes re$uests in parallel without

mandatory $uery tuning. Teradata's parallelism does not depend on limited data $uantity!

column range constraints! or speciali1ed data models ++ Teradata has :+nconditional

parallelis.:

;. #%ility to /odel the


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-ig+re ' !

% data warehouse built on a business model contains inormation rom

across the enterprise. ndividual departments can use their own assumptions and views o

the data or analysis! yet these varying perspectives have a common basis or a #singleversion o the truth.#

,ith Teradata's centrally located! logical architecture! companies can get a

cohesive view o their operations across unctional areas to

5ind out which divisions share customers.

Trac" products throughout the supply chain! rom initial manuacture! to inventory!

to sale! to delivery! to maintenance! to customer satisaction.

%naly1e relationships between results o dierent departments.

Determine i a customer on the phone has used the company's website.

/ary levels o service based on a customer's proitability.

8ou get consistent answers rom the dierent viewpoints above using a

single business model! not unctional models or dierent departments. n a unctional

model! data is organi1ed according to what is done with it. But what happens i users later

want to do some analysis that has never been done beoreK ,hen a system is optimi1ed or

one department's unction! the other departments' needs (and uture needs) may not be met.

% Teradata system allows the data to represent a business model! with data

organi1ed according to what it represents! not how it is accessed! so it is easy to understand.

The data model should be designed with regard to usage and be the same regardless o data

volume. ,ith Teradata as the enterprise data warehouse! users can as" new $uestions o the

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data that were never anticipated! throughout the business cycle and even through changes in

the business environment.

% "ey Teradata strength is its ability to model the customer's business.

Teradata's business modelsare truly normali1ed! avoiding the costly star schema and

snowla"e implementations that many other database vendors use. Teradata can do Star

Schema and other types o relational modeling! but Third &ormal 5orm is the methodology

Teradata recommends to customers. Teradata's competitors typically implement Star

Schema or Snowla"e models either because they are implementing a set o "nown $ueries

in a transaction processing environment! or because their architecture limits them to that

type o model. &ormali1ation is the process o reducing a comple7 data structure into a

simple! stable one. Aenerally this process involves removing redundant attributes! "eys! and

relationships rom the conceptual data model. Teradata supports normali1ed logical models

because Teradata is able to perorm 7" ta%le =oinsand large aggregations during $ueries.

/at+re arallel'#5are Optii8er

Teradata's ?ptimi1er is the most robust in the industry! able to handle

Multiple comple7 $ueries

@oins per $uery

nlimited ad+hoc processing

The ?ptimi1er is parallel+aware! meaning that it has "nowledge o system

components (how many nodes! vprocs! etc.). t determines the least e)pensive plan tie'

5ise3to process $ueries ast and in parallel.

(vol+tion to #ctive Data Wareho+sing>

Data Wareho+se Usage (vol+tion

There is an inormation evolution happening in the data warehouse

environment today. 0hanging business re$uirements have placed demands on data

warehousing technology to do more things aster. Data warehouses have moved rom bac"

room strategic decision support systems to operational! business+critical components o the

enterprise. %s your company evolves in its use o the data warehouse! what you need rom

the data warehouse evolves! too.

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-ig+re ' "

*tage 1 Reporting> The initial stage typically ocuses on reporting rom a single source o

truth to drive decision+ma"ing across unctional andJor product boundaries. Huestions are

usually "nown in advance! such as a wee"ly sales report.

*tage 2 #naly8ing>5ocus on why something happened! such as why sales went down or

discovering patterns in customer buying habits. sers perorm ad+hoc analysis! slicing and

dicing the data at a detail level! and $uestions are not "nown in advance.

*tage ! redicting> Sophisticated analysts heavily utili1e the system to leverage

inormation to predict what will happen ne7t in the business to proactively manage the

organi1ation's strategy. This stage re$uires data mining tools and building predictive models

using historical detail. %s an e7ample! users can model customer demographics or target

mar"eting.

*tage " Operationali8ing> *roviding access to inormation or immediate decision+ma"ing

in the ield enters the realm o active data warehousing. Stages 2 to < ocus on strategic

decision+ma"ing within an organi1ation. Stage : ocuses on tactical decision support..

Tactical decision support is not ocused on developing corporate strategy! but rather on

supporting the people in the ield who e7ecute it. 97amples 2) nventory management with

Fust+in+time replenishment! -) Scheduling and routing or pac"age delivery.


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as operational data store OD*3 level inforation. %nd or %oth strategic and tactical

decisionsto be useul to the business! today's data! this hour's data! even this minute's data

has to be at hand.

Teradata is positioned e7ceptionally well or stepping up to the challenges

related to high availability! large multi+user wor"loads! and handling cople) 6+eriesthat

are re$uired or an active data warehouse implementation. Teradata technology supports the

evolving business re$uirements by providing high perforance and scala%ilityor

Mi7ed wor"loads (both tactical and strategic $ueries) or mission critical

applications

=arge amounts o detail data

0oncurrent users

Teradata provides 9)2" availa%ility and relia%ility! as well as continuous

updating o inormation so data is al5ays fresh and acc+rate

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Teradata acts as a single data store! with multiple client applications ma"ing

in$uiries against it concurrently.

nstead o replicating a database or dierent purposes! with Teradata you

store the data once and use it or all clients. Teradata provides the same connectivity

or an entry+level system as it does or a massive enterprise data warehouse.

10. Teradata *yste

% Teradata system contains one or more nodes. % node is a term or a

processing unit under the control o a single operating system. The node is where the

processing occurs or the Teradata Database. There are two types o Teradata systems

Symmetric multiprocessing (SM*) + %n SM* Teradata system has a single node that

contains multiple 0*s sharing a memory pool.

Massively parallel processing (M**) + Multiple SM* nodes wor"ing together

comprise a larger! M** implementation o Teradata. The nodes are connected using

the B8&9T! which allows multiple virtual processors on multiple nodes to

communicate with each other.

-ig+re ' 9 Teardata *yste

To manage a Teradata system! you use

SM* system System 0onsole ("eyboard and monitor) attached directly to the SM*

node

M** system %dministration ,or"station (%,S)

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To access a Teradata system! a user typically logs on through one o multiple

client platorms (channel+attached mainrames or networ"+attached wor"stations). 0lient

access is discussed in the ne7t module.

Node Coponents

% node is a basic building bloc" o a Teradata system! and contains a large

number o hardware and sotware components. % conceptual diagram o a node and its

maFor components is shown below. Iardware components are shown on the let side o the

node and sotware components are shown on the right side.

-ig+re @ ; Node Coponent

*hared Nothing #rchitect+re

The Teradata vprocs (which are the *9sand %M*s) share the components

o the nodes (memory and cpu). The main component o the #shared+nothing# architecture

is that each %M* manages its own dedicated portion o the system's dis" space (called the

vdis") and this space is not shared with other %M*s. 9ach %M* uses system resources

independently o the other %M*s so they can all wor" in parallel or high system

perormance overall.

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Using the %n M** system typically has two B8&9T networ"s (B8&9T

and B8&9T 2). Because both networ"s in a system are active! the system beneits

rom having ull use o the aggregate bandwidth o both the networ"s.

-a+lt tolerant>9ach networ" has multiple connection paths. the B8&9T detects

an unusable path in either networ"! it will automatically reconigure that networ" so

all messages avoid the unusable path. %dditionally! in the rare case that B8&9T

cannot be reconigured! hardware on B8&9T is disabled and messages are re+

routed to B8&9T 2.

&oad %alanced>Traic is automatically and dynamically distributed between both

B8&9Ts.

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11. Teradata *oft5are

arsing (ngine

% *arsing 9ngine is a vproc that manages the dialogue between a client

application and the Teradata Database! once a valid session has been established.

9ach *9 can support a ma7imum o 120 sessions.

#/

The%M*is a vproc that controls its portion o the data on the system. The

%M*s wor" in parallel! each %M* anaging the data ro5s stored on its vdisB. %M*s are

involved in data distribution and data access in dierent ways.

Channel Driver

0hannel Driver sotware is the means o communication between an

application and the *9s assigned to channel+attached clients. There is one 0hannel Driver

per node.

Teradata ate5ay

Teradata Aateway sotware is the means o communication between an

application and the *9s assigned to networ"+attached clients. There is one Teradata

Aateway per node.

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12. Teradata Wareho+se


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-ig+re @ Teradata Wareho+se

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1!. What Is *&?

-ig+re @ 10 #ccessing of Teradata

Teradata is accessed using SH= (Structured Huery =anguage). SH= is the

industry standard access language or communicating with a relational database. SH= is a

set+oriented language or relational database management. % user or application can use

SH= statements to perorm operations on the data and deine how an answer set should be

returned rom an RDBMS.

Teradata supports two types o SH=

#N*I *&>Teradata SH= is compliant with %&S standards (an industry standard).

Teradata *& ()tensions>&0R has added Teradata SH= e7tensions above and

beyond standard SH= capabilities! including one+step SH= statements or comple7administrative operations.

Teradata *&


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Database! along with its automatic data distribution! balances the wor"load and

reduces bottlenec"s.

#N*I Copliant 'Teradata SH= is compliant with %&S standards. you have

programs already written with %&S+compliant SH= or a dierent relational

database! you can run them with Teradata! as well. 4igh'erforance ()tensions '&0R has added Teradata SH= e7tensions that are

above and beyond the standard SH= capabilities! including one+step SH= statements

or comple7 administrative operations.

User #ssistance *tateents and /odifiers

SH= user assistance statements (and modiiers) vary widely rom database

vendor to database vendor. Teradata's user assistance statements are commonly called

Teradata e7tensions. These Teradata e7tensions are additions to the DD=! DM=! and D0=

statements in standard SH=! and ma"e some operations less time consuming.

This page discusses the ollowing Teradata SH= user assistance commands

I9=*

I9=* S9SS?&

SI?,

This page also discusses the statement modiier

9*=%&

The 4(& *tateent

The I9=* statement is used to display inormation about database obFects.

8ou can get help on the ollowing

I9=* D%T%B%S9

I9=* S9R

I9=* T%B=9

I9=* /9,

I9=* M%0R?

I9=* TRAA9R

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I9=* *R?09DR9

I9=* 0?=M&

I9=* &D9

I9=* ST%TST0S

. . . and much moreL

()aple>

I9=* D%T%B%S9 databasename

Displays all the obFects in the speciied database.

The 4(& *(**ION *tateent

se the I9=* S9SS?& statement to see speciic inormation about your

SH= session.

()aple>

I9=* S9SS?&

Displays the user name with which you logged in! the log+on date and time!your deault database! and other inormation related to your current session.

The *4OW *tateent

se the SI?, statement to display the data deinition language (DD=)

associated with database obFects (tables! views! macros! triggers! or stored procedures). 8ou

can show the DD= or the ollowing

SI?, T%B=9

SI?, /9,

SI?, M%0R?

SI?, TRAA9R

SI?, *R?09DR9

SI?, @?& &D9

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()aple>

SI?, T%B=9 tablename

Displays the 0R9%T9 T%B=9 statement that was used to create the speciied table.

The (EIN /odifier

The 9*=%& modiier allows you to preview how Teradata will e7ecute an

SH= re$uest. t is a good way to see what database resources will be used in processing the

re$uest. se the 9*=%& modiier preceding any SH= statement to see a plan with

9nglish te7t describing a plan or how the statement will be processed.

%n estimate o the number o rows involved.

% relative cost o the re$uest.

The relative cost is shown in units o time! and should not be used to predict

actual response time or an SH= re$uest. This time estimate can be used to compare the

duration o re$uest processing relative to other plans.

,hen you e7ecute a re$uest preceded by the 9*=%& modiier! the re$uest is not

e7ecuted. nstead! the system

5ully parses the re$uest.

?ptimi1es the re$uest.

Reports the complete plan or e7ecuting the re$uest in readable 9nglish.

()aple>

9*=%& S9=90T N 5R?M tablename

Displays the steps involved in processing the re$uest! S9=90T N 5R?M

the speciied table.

1". # Teradata Data%ase

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n Teradata systems! the words #database# and #user# have speciic

deinitions.

Data%ase> The Teradata Definition

n Teradata! a #database# provides a logical grouping o inormation. %

Teradata Database also provides a "ey role in space allocation and access control. %

Teradata Database is a deined! logical repository that can contain obFects! including

Data%ases> % deined obFect that may contain a collection o Teradata obFects.

Users> Databases that each have a logon D and password or logging on to

Teradata.

Ta%les>Two+dimensional structures o columns and rows o data stored on the dis"

drives.

Fie5s> % virtual #window# to subsets o one or more tables or other views! pre+

deined using a single S9=90T statement.

/acros> Deinitions o one or more Teradata SH= and report ormatting

commands.

Triggers> ?ne or more Teradata SH= statements associated with a table and

e7ecuted when speciied conditions are met.

*tored roced+res>0ombinations o procedural and non+procedural statements run

using a single 0%== statement

Note>% Database 5ith no er *pacecan have views! macros! and triggers! but no

tables or stored procedures.

These Teradata obFects are created! maintained! and deleted using SH=! and

are described in urther detail in this section.User> # *pecial Gind of Data%ase

% ser can be thought o as a colllection o tables! views! macros! triggers!

and stored procedures. % ser is a speciic type o Database! and has attributes in addition

to the ones listed above

=ogon D

*assword

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up! a single $uery could temporarily use all available System Space to store its result

in spool. *ermanent Space not being used or tables is available or Spool Space.

Tep *pace>The amount o space used or global temporary tables! and these

results remain available to the user until the session is terminated. Tables created in

Temp Space will survive a restart. *ermanent Space not being used or tables isavailable or Temp Space as well as Spool Space.

1,. rotecting Data

Several types o data protection are available with Teradata. Some o them are +

Red+ndant #rray of Ine)pensive DisBs R#ID3 is a storage technology that

provides data protection at the dis" drive level.

-all%acBis a Teradata eature that protects data against %M* ailure. %s shown

later in this module! 5allbac" uses groups o %M*s that provide or data availability

and consistency i an %M* is unavailable.

&ocBingprevents multiple users who are trying to access or change the same data

simultaneously rom violating data integrity. This concurrency control is

implemented by loc"ing the target data. =oc"s are automatically ac$uired during theprocessing o a re$uest and released when the re$uest is terminated.

=oc"s may be applied at three levels

Data%ase &ocBs>%pply to all tables and views in the database.

Ta%le &ocBs>%pply to all rows in the table.

Ro5 4ash &ocBs>%pply to a group o one or more rows in a table

Temporary loc"s can be placed on data to prevent multiple users rom

simultaneously changing it

97clusive =oc"

,rite =oc"

Read =oc"

%ccess =oc"

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Ho+rnalscan be used or speciic types o data or process recovery

*ermanent @ournals

Recovery @ournals

Transient @ournal

*ermanent @ournals are an optional eature o Teradata to provide an

additional level o data protection. 8ou speciy the use o *ermanent @ournals at the table

level. t provides ull+table recovery to a speciic point in time. t also can reduce the need

or costly and time+consuming ull+table bac"ups. *ermanent @ournals are tables stored on

dis" arrays li"e user data is! so they ta"e up additional dis" space on the system. The

Teradata DB% (Database %dministrator) maintains the *ermanent @ournal entries (deleting!

archiving! and so on.)

The Teradata Database uses Recovery @ournals to automatically maintain data

integrity in the case o

%n interrupted transaction Transient Ho+rnal3

%n %M* ailure Do5n'#/ Recovery Ho+rnal3

Recovery @ournals are created! maintained! and purged by the system

automatically! so no DB% intervention is re$uired. Recovery @ournals are tables stored on

dis" arrays li"e user data is! so they ta"e up additional dis" space on the system.

% Transient @ournal maintains data integrity when in+light transactions are

interrupted (due to aborted transactions! system restarts! and so on). Data is ret+rned to its

original stateater transaction ailure. % Transient @ournal is used during normal system

operation to "eep #beore images# o changed rows so the data can be restored to its

previous state i the transaction is not completed. This happens on each #/as changes

occur. ,hen a transaction is started! the system a+toaticallystores a copy o all the rows

aected by the transaction in the Transient @ournal until the transaction is committed

(completed). ?nce the transaction is complete! the #beore images# are purged. n the event

o a transaction ailure! the #beore images# are reapplied to the aected tables and deleted

rom the Fournal! and the #rollbac"# operation is completed.

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17. Concl+sion

Teradata is the uture o the Data Mining. n uture everyone we start using

Teradata Database. &ow it is costly! wor"s are going on to reduce its cost. So! it will reach

to small business people also.

Reference>

2. www.teradata.com

-. www.google.com

Seminar Report - Teradata is a Relational Database Managemen

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Transcript of Seminar Report - Teradata is a Relational Database Managemen