Teradata Interview Questions and Answers

Teradata Interview Questions and answers

Question.1 What is the diference between FastLoad and MultiLoad? Answer: FastLoad uses multiple sessions to quickly load large amount of data on empty table. MultiLoad is used for high-volume maintenance on tables and views. It works with non-empty tables also. Maximum  tables can be used in MultiLoad. Question.2 Which is aster? Answer: FastLoad. Question.3 Diference between nner !oin and outer !oin? Answer: !n inner "oin gets data from both tables where the speci#ed data exists in both tables. !n outer "oin gets data from the source table at all times$ and returns data from the outer "oined table %&L' if it matches the criteria.(sociallocker) Question." What is #ulti nsert? Answer: Inserting data records into the table using multiple insert statements. *utting a semi colon in front of the key word I&+, in the next statement rather than terminating the #rst statement with a semi colon achieves it. Insert into +ales /select 0 from customer1 Insert into Loan /select 0 from customer12 Question.$ s #ulti insert A%& standard? Answer: &o. Question.' (o (ow w do )o )ou u cr crea eate te a ta tabl ble e wi with th an e* e*is isti tin+ n+ st stru ruct ctur ure e o  another table with data and with no data? Answer: 3reate table 3ustomer dummy as 3ustomer with data 4 with no data2 Question., What is the o-enin+ ste- in asic /eradata /eradata Quer) scri-t? Answer: Logon tdipid4username$ password. Question.0    ou ou are callin+ a te scri-t which dro-s a table table and creates a table. t will throw an error i the table does not e*ist. (ow can )ou do it without throwin+ the error? Answer: ' Answer:  'ou ou can it by setting error level to 5ero before dropping and resetting the error level to 6 after dropping. Question.4 56676L585L 930,; Answer: +,7,I' 62 Question.1 e) b) -uttin+ eualit) on that >e)? Answer: &o. Question.11 Did )ou write stored -rocedures in /eradata?

Answer: &o$ because they become a single amp operation and my company didn8t encourage that. Question.12 What is the use o hain+ inde*@s on table? Answer: For faster record search. Question.13 Did )ou use Quer) #an or &QL assistance? Answer: +9L assistant :.; Question.1".  a# u-dat u-datin in+ + a ta tabl ble e in t te e.. t ha has s to uu-da date te a la lar+ r+e e nu#ber o rows so it@s reall) slow. What do )ou su++est? Answer: In eradata eradata it is not recommended to update more than ; million rows due to "ournal space problems$ if it is less than that and it8s slow in the month from ?. +ame thing for year or day.%r hour or minutes if it8s a time stamp >select extract >minute from column name?. Question.1, What@s the s)nta* o sub strin+? Answer: +=<+I&@ >stringAexpression$ >stringAexpression$ n; (nB)? Question.10 Did )ou use
Informatica ,L Interview 9uestions and !nswers Question.1
Question.3 What are stored -rocedure transor#ations. ur-ose o s- trar sor#ation. (ow did )ou +o about usin+ )our -ro!ect? Answer: 3onnected and unconnected stored stored procedure. procedure. =nconnected stored procedure used for data base level activities such as pre and post load 3onnected stored procedure used in informatica level for example passing one parameter as input and capturing return value from the stored procedure. procedure.  &ormal  row wise check *re-Load *re-Loa d +ource  >3apture source incremental data for incremental aggregation? aggregation? *ost-Load +ource  >Eelete emporary tables? *re-Load arget  >3heck dick space available? *ost-Load arget G >Erop and recreate index? Question." What is loo>u- and diference between /)-es /)-es o loo>u-. What e*actl) ha--ens when a loo>u- is cached. (ow does a d)na#ic: loo>ucache wor>. Answer: Loo Lookup kup transforma transformation tion used for check values in the source and target tabl ta bles es>p >pri rima mary ry key va valu lues es?. ?. h her ere e ar are e B ty type pe co conne nnect cted ed an and d unc uncon onne nect cted ed transformation 3onnected lookup returns multiple values if condition true Chere as unconnected return a single values through return port. 3onnected lookup return return default user value if the condition does not mach Chere as unconnected return null values Lookup cache doesH ead the source4target table and stored in the lookup cache . Question.$ (ow did )ou )ou schedule sessions in )our -ro!ect? -ro!ect? Answer: un once >set B parameter date and and time when session should start? start? un ,ver ,v ery y >I >Inf nfor orma mati tica ca se serve rverr run se sess ssio ion n at re regu gula larr int inter erva vall as we co con#g n#gur ured ed$$ parameter Eays$ hour$ minutes$ end on$ end after$ forever? 3ustom 3us tomi5e i5ed d re repea peatt > >epe epeat at eve every ry B day days$ s$ dai daily ly fr frequ equenc ency y hr$ min min$$ eve every ry wee week$ k$ every month? un only on demand>Manually run? this not session scheduling. Question.' 5*-lain loo>u- cache cache arious caches? Answer: Loo Lookup kup transform transformation ation used for check values in the source and target tables>primary key values?. 7arious 3achesH *ersistent cache >we can save the lookup cache #les and reuse them the next time process the lookup transformation? e-cache from database >if the persistent cache not synchroni5ed with lookup table you can- con#gure the lookup transformation transformation to rebuild the lookup cache? +tatic cache >Chen the lookup condition is true$ Informatica server return a value from lookup cache and it8s does not update the cache while it processes the lookup transformation? Eynamic cache >Informatica server dynamically inserts new rows or update existing rows in the cache and the target. +uppose if we want lookup a target table we can use dynamic cache?

+ha harred cac ache he >we can sh sha are lo look okup up tra rans nsfo forrma mati tio on bet etw ween mu mult ltip iple le transf tra nsfor ormat mation ions s in a map mappin ping.B g.B loo looku kup p in a map mappin ping g ca can n sha share re sin single gle loo looku kup p cache? . Question., Which -ath will the cache be created? Answer: =ser speci#ed speci#ed directory directory. If we say cH all the cache #les created created in this directory. Question.0 where do )ou s-eci) all the -ara#eters or loo>u- caches? Answer: Look Lookup up property property sheet4tab. Question.4 (ow do )ou re#oe the cache =les ater the transor#ation? Answer: !f !fter ter session complete$ EM remove remove cache memory and deletes caches caches #les. In case using persistent cache and Incremental aggregation then caches #les will be saved. Question.1 What is the use o a++re+ator transor#ation? Answer: o perform !ggregate !ggregate calculation =se conditional clause to #lter data data in the expression +um>commission$ 3ommission JBKKK? =se non-aggregate function if  >max>quantity? J K$ Max>quantity?$ K?? Question.11 What are the contents o inde* and cache =les? Answer: Inde Index x caches #les hold unique unique group values values as determined determined by group group by portt in Ath por Athe e tra transf nsfor ormat mation ion.. Eat Eata a cac caches hes #le #les s hol hold d ro row w dat data a unt until il it per perfor forms ms necessary calculation. Question.12 (ow do )ou call a store -rocedure within a transor#ation? Answer: In the expr expressio ession n transformatio transformation n cre create ate new out port in the expr expression ession writeH sp. stored procedure name >arguments?. Question.1 Quest ion.13 3 s there an) -eror#ance -eror#ance issue in conne connected cted E uncon unconnecte nected d loo>u-?  )es (ow? Answer: 'es =nconnected =nconnected lookup much more faster than connected connected lookup why because in unconnected not connected to y other transformation we are calling it from other transformation so it minimi5e lookup cache value Chere as connected transformation connected to other transformation so it keeps values in the lookup cache. Question.1" What is d)na#ic loo>u-? Answer: Chen we use targ target et lookup lookup table$ Informati Informatica ca server dynamically dynamically insert new values or it updates if the values exist and passes to target table. Question. Quest ion. 1$ (ow lncr#atica lncr#atica read data i sourc source e hae one relat relational ional and at =le? Answer: =s =se e "o "oiine nerr tra rans nsfo forrma mati tion on af afte terr so sour urc ce qua ualli# i#er er be befo forre ot othe herr transformation. Questi Que stion. on.1' 1' (ow )ou wil willl loa load d uni uniue ue rec record ord int into o tar tar+et +et at =le ro ro# # source 13t =les has du-licate data? Answer: her here e are B we can can de this either either we can use . . ink transform transformation ation or oracle external table in rank transformation using group by port >@roup it e records? and then set no. of rank ;. ank transformation return one value from the group.  hat the values wit Ee a unique one.

Question.1,
Informatica Interview Questions with answers Question.1 What are the diferent uses o a re-ositor) #ana+er? Answer: eposito epository ry manager used to create repository which contains metadata the informatca uses to transform data to from source to target. !nd also it u se to create inforrnatica user8s and folders and copy$ backup and restore tie repository . Question.2 (ow do )ou ta>e care o securit) usin+ a re-ositor) #ana+er? Answer: =sing repository privileges$ folder permission and locking. epository privileges>+ession operator. operator. =se designer$ owner$ groups$ users? . Locking> Locking>ead$ ead$ Crite$ ,xecute$ Fetch$ +ave? . (sociallocker) Question.3 What is a older? Answer: Folder contains repository ob"ects such as sources$ targets$ mappings$ transformation which are helps logically$ organi5e our data warehouse. Question." Local and global? Local Local used in local repository repository and global used in global repository. repository. he advantage is reusing an ob"ect without creating multiple ob"ects. +ay for example a source de#nition want to use in ;K mappings in ;K diOerent folders without creating ;K multiple source you create ;K shortcuts. Question.' how do )ou increase the -eror#ance o #a--in+s? Answer: =se single pass read>use one source quali#er instead of multiple +% for same table? Minimi5e data type conversion >Integer to Eecimal again back to Integer? %ptimi5e transformation>when you use Look Lookup$ up$ aggregator$ #lter$ rank and  "oiner?.

=se caches for lookup !ggregator !ggregator use presorted port$ increase cache si5e$ minimi5e input4out port as much as possible =se Filter Filter wherever possible to avoid unnecessary data ow ow.. Question., 5*-lain lnor#atica Architecture? Answer: Informatica consist of client and server server.. 3lient tools such as epository -manager$ Eesigner$ +erver manager. epository epository data base contains metadata it read by inforrnatica server used read data from source$ transforming and loading into target. Question.0 What are the constants used in u-date strate+)? Answer: %EAI&+,$ EEA=*E!,$ EEAE,L,,$ EE ,P,3. Question.4 what is diference between connected and unconnected loo>utransor#ation? Answer: 3onnected lookup return multiple values to other transformation Chere as unconnected lookup return one values If lookup condition matches 3onnected lookup return user de#ned default values Chere as unconnected lookup return null values 3onnected supports dynamic caches where as unconnected supports static. Question.1 What Question.1  What )ou will do in session leel or u-date strate+) transor#ation? Answer: In session property sheet set reat rows as /Eata Eriven1 . Question.11 What are the -ort aailable or u-date strate+)  seuence +enerator Loo>u- stored -rocedure transor#ation? +enerator Answer:  ransformations   ransformations *ort •

=pdate strategy +equence @enerator Lookup

Input$ %utput %utput only Input$ %utput$ Lookup$ eturn

+tored *roced *rocedure ure

Input$ %utput

Question.12 what is an actie and -assie transor#ation? Question.12 what Answer: !ctive transformation change the no. of records when passing to targe>example targe>exam ple #lter? where as passive transformation will not change the transformation>example transformation>exa mple expression? . Question.13 What are the tracin+ leel? Answer: &ormal  It contains only session initiali5ation details and transformation details no. records re"ected$ applied  erse   erse  %nly initiali5ation initiali5ation details will be there 7erbose 7erbose Initiali5ation Initiali5ation G &ormal setting information plus detailed information about the transformation. 7erbcse data G 7erbose in it. +ettings and all information about the session . Question.1"

(ow will )ou #a>e records in +rou-s?

Answer: =sing group by port in aggregator . Question.1$ %eed to store alue li>e 1"$ into tar+et when )ou use a++re+ator how will )ou do that? Answer: =se ound>? function Question.1' (ow will )ou #oe #a--in+s ro#  ro# deelo-#ent to -roduction database? Answer: 3opy all the mapping from development repository and paste production repository while paste it will prompt whether you want replace4rename. If say replace informatica informatica replace all the source tables with repository database. Question.1, What is diference between a++re+ator and e*-ression? Answer: !ggregator Answer:  !ggregator is active transformation and expression is passive transformation !ggregator transformation used to perform aggregate calculation on group of records really Chere as expression used perform calculation with single record. Question.10 What Question.10  What are 6outer transor#ation? Answer: outer transformation is an !ctive and 3onnected transformation. It is similar to #lter transformation. he only diOerence is$ #lter transformation drops the data that do not meet the condition whereas router has an option to capture the data that do not meet the condition. It is useful to test multiple mu ltiple conditions. Question.14 What are &orter transor#ation? Answer: +orter transformation is a 3onnected and an !ctive transformation. It allows to sort data either in ascending or descending order according according to a speci#ed #eld.(4sociallocker)

Informatica Interview Questions experienced Question.1 (o (ow w to Ho Hoin in 2 ta tabl bles es co conn nnec ecte ted d to a &o &our urce ce Qu Qual ali= i=er er wI wIo o hain+ an) relationshi- de=ned . Answer: if no relationship at oracle level? % arget Load Loa d *lan >if only only ; source source quali#er quali#er for other tabl tables? es? % select select #rst the header header target table and then the detail table while dragging them in mapping.(sociallocker) mapping.(sociallocker) Question.3 A #a--in+ !ust ta>e 1 seconds to run it ta>es a source =le and an d in inse sert rt in into to ta tar+ r+et et bu butt be beo ore re th that at th ther ere e is a &t &tor ored ed r roc oced edur ure e transor#a trans or#ation tion which ta>es around $ #inu #inutes tes to run and +ies out-ut J@ or J% J%@. @.   th then en co cont ntin inue ue e eed ed or el else se st stoo- th the e e eed ed.. 9( 9(in int: t: si sinc nce e & transor#ation ta>es #ore ti#e co#-ared to the #a--in+ it shouldn@t run row wise;.

Answer: here is an an option to run the stored procedure before starting starting to load the rows. Question." What is diference between iew and #aterialiCed iew? Answer: 7iews contains query whenever execute views it has read from base table Chere Cher e as M views loading loading or replicated replicated tak takes es place only once$ once$ which gives you bett be tter er qu quer ery y pe perf rfor orma manc nce e .r .ref efre resh sh m vi view ews s ;. ;.on on co comm mmit it an and d B. on de dema mand nd >3omplete$ never$ fast$ force? . Question.$ What is bit#a- inde* wh) it@s used or DW(? Answer: bitmap for each key value replaces a list of rowids. e sche#a? Answer:  he center of the star consists of a large fact table and the points of the star are the dimension dimension tables. snowake schemas schemas normali5ed dimension dimension tables to eliminate redundancy. hat is$ the Eimension data has been grouped into multiple tables instead of one large table. +tar schema contains demorali5ed dimension tables and fact table$ each primary key values in dimension table associated with foreign key of fact tables. Rere a fac Rere factt tab table le co conta ntains ins all bus busine iness ss mea measur sures es >no >norm rmall ally y num numeri eric c dat data? a? and foreig for eign n key val values ues$$ and dim dimens ension ion tab tables les has det detail ails s abo about ut the sub sub"ec "ectt ar area. ea. +nowake schema basically a normali5ed dimension tables to reduce redundancy in the dimension tables . Question., Wh) need sta+in+ area database or DW(? Answer: +taging area needs to clean operational data before loading into data warehouse. cleaning in the sense your merging data which comes from diOerent source . Question.0 What are the ste-s to create a database in #anuall)? Answer: create %+ service and create init #le and start data base no mount stage then give create data base command. Question.4 Diference between 7L/ and DW(? Answer: %L* system is basically application orientation >eg$ purchase order it is functionality of an application? Chere as in ECR concern is sub"ect orient >sub"ect in the sense customer$ product$ item$ time? . Question.1 What is the si+ni=cance o surro+ate >e)? Answer: +urrogat +urrogate e key used in slowly slowly changing dimension table table to track track old and new values and its derived from primary key. Question.11 What is slowl) chan+in+ di#ension. What >ind o scd used in )our -ro!ect?

Answer: Eimension attribute values may change constantly over the time. >+ay for examp ex ample le cus custom tomer er di dimens mension ion has cus custom tomerA erAid id $na $name$ me$ and add addre ress$ ss$ cus custom tomer er address may change over time. Question.12 6ow will )ou handle this situation? Answer:  here are S types$ one is we can overwrite the existing record$ second one is create additional new record at the time of change with the new attribute values. value s. hir hird d one is cre create ate new #eld to ke keep ep new values in the origi original nal dimension dimension table. Question.13 Wh What at is di dife fere renc nce e be betw twee een n -r -ri# i#ar ar) ) >e) an and d un uni iue ue >e) constraints? Answer: *rimary key maintains uniqueness and not null values Chere as unique constrains maintain unique values and null values Question.1" What are the t)-es o inde*? And is the t)-e o inde* used in )our -ro!ect? Answer: name? a$ set a.empnoT;K where enameT8!shok8 Question.1' When )ou +ie an u-date state#ent how #e#or) ow will ha--en and how oracles allocate #e#or) or that? Answer: %racle #rst checks in +hared sql area whether same +ql statement is available if it is there it uses. %therwise allocate memory in shared sql area and then create run time memory in *rivate sql area to create parse tree and execution plan. %nce it completed stored in the shared sql area wherein previously allocated memory . Question.1, Write a uer) to =nd out $th #a* salar)? n 7racle D2 &QL &erer Answer: +el +elect ect >l >list ist the col columns umns you wan want? t? fr from om >se >selec lectt sal salary ary fr from om emp employ loyee ee order by salary? Chere rownumU Question.10 Wh When en )o )ou u +i +ie e an uu-da date te st stat ate# e#en entt ho how w un undo doIr Irol ollb lbac ac>  >  se+#ent will wor>Iwhat are the ste-s? Answer: %racle keep old values in undo segment and new values in redo entries. Chen you say rollback it replace old values from undo segment. Chen you say commit erase the undo segment values and keep new vales in permanent. Question.14 What is D/M? (ow will )ou con=+ure it? Answer: E EM M tr tran ansf sfor orm m da data ta rec ecei eive ved d fr from om rea eade derr bu buOe Oerr an and d it its s mo move ves s transformation to transformation on row by row basis and it uses transformation caches when necessary.(4sociallocker)

Informatica Interview questions with answers Question.1 Wha Whatt are the co# co#-on -onent ents s o n nor# or#ati atica? ca? And wha whatt is the -ur-ose o each? Answer: Informatica Eesigner$ +erver Manager V eposito epository ry Manager. Manager. Eesigner for 3r 3reat eating ing +ou +ourc rce e V ar arget get de# de#nit nition ions$ s$ 3r 3reat eating ing Map Mapple plets ts and Map Mappin pings gs etc etc.. +erver Manager for creating sessions V batches$ +cheduling the sessions V batches$ Moni Mo nito tori ring ng th the e tr trig ig "e "ere red d se sess ssio ions ns an and d ba batc tche hes$ s$ gi givi ving ng po post st an and d pr pre e se sess ssio ion n commands$ comm ands$ cre creating ating data database base connec connections tions tc vario various us insta instances nces etc. e eposi pository tory Manage for 3reating and !dding repositories$ 3reating V editing folders within a repository$ ,stablishing users$ groups. privileges V folder permissions$ 3opy. delete$ bac Hup a repository$ 7iewing the history of sessions$ 7iewing the locks on various ob"ects and removing those locks etc. Question.2 What is a re-ositor)? And how to add it in an inor#atica client? Answer: It8s a location where where all the mappings and sessions related related information is stor st ored ed..
Question.' 5*-lain what is sl oerride or a source taLle in a #a--in+? Answer:  he +ource 9uali#er provides the +9L 9uery option to override the default query. query. 'ou 'ou can enter any +9L statement supported su pported by your source database.  'ou  ' ou might enter your own +,L,3 statement$ or have the database perform aggregate calculations$ or call a stored procedure or stored function to read the data and perform some tasks. Question., What is loo>u- oerride? Answer: !i !ils lsHH h his is fe feat atur ure e is si simi mila larr to enteri entering ng a cu cust stom om query query in a +o +our urce ce 9uali#er transformation. Chen entering a Lookup +9L %verride$ you can enter the entire override$ or generate and edit the default +9L statement.  he lookup query query override can include CR,, CR,, clause. Question.0 Wh What at ar are e #a #a---le lets ts? ? (o (ow w is it di dife fere ren nt r ro# o# a 6e 6eus usab able le /ransor#ation? Answer: ! mapplet is a reusable ob"ect ob"ect that represents a set of transformations. transformations. It allows you to reuse transformation logic and can contain as many transformations as you need. 'ou create mapplets in the Mapplet Eesigner. Its diO iOer eren entt tha han n a reu eusa sab ble tra rans nsfo forrma mati tio on as it may co cont nta ain a se sett of  transformations$ while a reusable transformation is a single one. Question.4 (ow to use an oracle seuence +enerator in a #a--in+? Answer: Ce have to write a stored procedure$ which can take the sequence name as input and dynamically generates a nextval from that sequence. hen in the mapping we can use that stored procedure through a procedure transformation. Question. 1 (ow to create the source and tar+et database connections in serer #ana+er? Answer: In the main men enu u of server manager ther ere e is menu /+erver 3on#guration1$ in that there is the menu /Eatabasesi connections1. From here you can create the +ource and arget database connections. Question. Quest ion. 11 Wh Wher ere e ar are e th the e so sour urce ce a att =l =les es >e >e-t -t be beor ore e ru runn nnin in+ + th the e session? Answer:  he source at #les can be kept in some folder on the Informatica server or any ether machine$ which is in its domain. Question. Quest ion. 12 What are the oracle DML co##ands -ossible throu+h an u-date strate+)? Answer: ddAinsert$ ddAupdate$ ddAdelete V ddAre"ec ddAre"ect. t. Question. 13 (ow to u-date or delete the rows in a tar+et which do not hae >e) =elds? Answer:    o o =pdate a table that does not have any Deys we can do a +9L %verride of the arget ransformation ransformation by>? specifying the CR,, conditions explicitly. explicitly. Eelete cannot be done this way way.. In this th is case you have to speci#cally mention mentio n the De Dey y for arg arget et tabl table e de#ni de#nition tion on the arge argett transf transforma ormation tion in the Carehouse Eesigner and delete the row using the =pdate +trategy transformation.

Question. 1" What is o-tion b) which we can run all the sessions in a batch si#ultaneousl)? Answer: In the batch edit box there is an opticn called concurrent. Ku-. Answer: !n unconnected Lookup transformation exists separate from the pipeline in the mapping. 'ou write an8" expression using the HLD* reference quali#er to call the lookup within another transformation. Chile the connected -lookup forms a part of the whole ow of mapping. Question. 10. 10. mainly to perform calculations on multiple rows or groups?.(4sociallocker) groups?.(4sociallocker)

Teradata Interview Questions and answers for Experienced Question.1 M) table +ot loc>ed durin+ ML7AD due to a ailed !ob. What do  do to -eror# other o-erations on it? Answer: =sing ,L,!+, ML%!E. It removes access locks from the target tables in  eradata.   eradata. It must be entered from <,9 and not from MultiLoad.    o o proceed$ you can do ,L,!+, ML%!E. Question.2 (ow to =nd du-licates in a table? Answer: @r @roup oup by tho those se #el #elds ds and select select id$ count>0? count>0? from from tab table le gr group oup by id having count >0? J ;. (sociallocker) (sociallocker) Question.3 (ow to )ou eri) a co#-licated &QL? Answer: I use explain statement to check if the query is doing what I wanted it to do. Question." Did u eer use 56 Function? Function?

Answer: =**, Function is used to convert all characters in a column to the same characters in upper case. Question.$ What does a L7W56 Function do? Answer: L%C, function is used to convert all characters in a column to the lower case characters. Question.' (ow do )ou see a DDL or an e*istin+ table? Answer: K? is 3R! >;Z? and IM,+!M* IM,+!M* >:? is 3R! >B:? ,verything is same except that IM,+!M* IM,+!M* >:? has microseconds too. Question.1 (ow do )ou deter#ine the nu#ber o sessions? Answer: [ eradata performance and workload [ 3lient platform type$ performance and workload [ 3hannel performance for channel attached systems [ &etwork topology and performance for network attached systems. [ 7olume of data to be processed by the application. Question.11 Wh What at is no node de? ? (o (ow w #a #an) n) no node des s an and d AM AM s us used ed in )o )our ur -reious -ro!ect? Answer: &ode is a database running in a server. Ce used S;6 nodes and each node has B to \ !M*+. Question.12 What is a cliue? Answer: 3lique is a group of disk arrays physically cabled to a group of nodes. Question.13 n nte ter rie iewer wer e* e*-l -lai aine ned d ab abou outt th thei eirr -r -ro! o!ec ectt 95 95n nir iron on#e #ent nt nature o wor>;? Answer: Listen to them carefully so that at the end of the interview you can ask questions about the pro"ect when you are given a chance to ask questions. of the pro"ect. Question.1"

What is the diference between FastLoad and MultiLoad?

Answer: FastLoad uses multiple sessions to quickly load large amount of data on empty table. MultiLoad is used for high-volume maintenance on tables and views. It works with non-empty tables also. Maximum  tables can be used in MultiLoad. Question.1$ (ae )ou used -rocedures? Answer: &o. I have not used procedures.
Informatica Interview Questions and answers for experienced

Question.1 What is the diference between connected and unconnected transor#ationW transor#ation W Answer: 3onnec 3onnected ted ransf ransforma ormationH tionH 3onnec 3onnected ted transf transform ormation ation is conne connected cted to other oth er tra transf nsfor ormat mation ions s or di dire rectl ctly y to tar target get tab table le in the map mappin ping. g. =nco =nconnec nnected ted  ransformationH   ransformationH !n unconnected transformation is not connected to other transf tra nsfor ormat mation ions s in the map mappin ping. g. It is cal called led wi withi thin n ano anothe therr tra transf nsfor ormat mation ion$$ and returns a value to that transformation. Question.2 What are arious t)-es o A++re+ation? Answer: 7arious types of aggregation are +=M !7@ v3%=& M!X MI& FI+ L!+ M,EI!& *,3,&IL, +EE,7 7!I!&3,. (sociallocker) Question.3 What are A++re+ator /ransor#ation? Answer: !ggregator transformation is an !ctive and 3onnected transformation.  his transformation is useful to perform calculations such as averages and sums >mainly to perform calculations on multiple rows or groups?. Question." What are 5*-ression transor#ation? Answer: ,xpression transformation is a *assive and 3onnected transformation.  his can be used to calculate calculate values in a single row row before writing writing to the target. Question.$ What are Filter transor#ation? Answer: Filter transformation is an !ctive and 3onnected transformation. his can be used to #lter rows in a mapping that do not meet the condition. Question.' What are Hoiner transor#ation? Answer:  Poiner ransformation is an !ctive and 3onnected transformation. his can be used to "oin two sources coming from two diOerent locations or from same location.

Question., Wh) we use loo>u- transor#ations? Answer: Lookup ransformations can access data from relational tables that are not sources in mapping. Question.0 What are %or#aliCer transor#ation? Answer: &ormali5er ransformation ransformation is an !ctive and 3onnected transformation. It is use used d ma main inly ly wi with th 3% 3%<% <%L L so sour urce ces s wh wher ere e mo most st of the ti time me da data ta is st stor ored ed in denor den ormal mali5e i5ed d for format mat.. !ls !lso$ o$ &or &ormal mali5e i5err tra transf nsfor ormat mation ion ca can n be use used d to cr creat eate e multiple rows from a single row of data. Question.4 What are 6an> transor#ation? Answer: ank transformatio transformation n is an !ct !ctive ive and 3onnec 3onnected ted trans transform formatio ation. n. It is used to select the top or bottom rank of data. Question.1 What are 6outer transor#ation? Answer: outer transformationis an !ctive and 3onnected transformation. It is similar to #lter transformation. he only diOerence is$ #lter transformation drops the data that do not meet the condition whereas router has an option to capture the data that do not meet the condition. It is useful to test multiple mu ltiple conditions. Question.11 What are &orter transor#ation? Answer: +orter transformation is a 3onnected and an !ctive transformation. It allows to sort data either in ascending or descending order according to a speci#ed #eld. Question.12 %a %a#e #e ou ourr ou outt-ut ut =l =les es th that at in ino or# r#at atio ion n se ser rer er cr crea eate tes s durin+ session runnin+? Answer: +ession Log Corkow Log ,rrors Log u>u- cac cache he and loo loo>u>uinde*? Answer: Look up 3ache contains Index cache and data cache. Index cache H 3ontains columns used in condition. Question.1" What are the diference between static cache and d)na#ic cache? Answer: Eyn Eynami amic c ca cache che dec decre rease ases s the per perfor forman mance ce in com compar pariso isons ns to sta static tic cache. +tatic cache do not see such things "ust insert data as many times as it is coming. Question.1$

De=ne #a-in+ and sessions?

Answer: MapingH It is a set of source and target de#nitions linked by transformation ob"ects ob"ects that de#ne the rules for for transformation. +ession H It is a set of instructions that describe how and when to move data from source to targets. Question.1' What is a co##and that used to run a batch? Answer: pmcmd is used to start a batch. Question.1, What is Datadrien? Answer:  he informatica server follows instructions coded into update strategy transformations with in the session maping determine how to ag records for insert$ update$ delete or re"ect. Question.10 What is -ower center re-ositor)? Answer:  he *ower 3enter repository allows you to share metadata across repositories to create a data mart domain. Question.14 What is -ara#eter =le? Answer: ! parameter #le is a #le created by text editor such as word pad or notepad. = can de#ne the following values in parameter #le. Maping parameters Maping variables session parameters.(4sociallo parameters.(4sociallocker) cker)

Informatica Interview Questions and Answers Question.1 What is Data warehouse? Answer: !ccording to operational data store? Eata Mart (sociallocker) Question.3 What is Data #art? Answer: ! Answer:  ! data mart is a subset of data warehouse that is designed for a particular line of business$ such as sales$ marketing$ or #nance. In a dependent data mart$ data can be derived from an enterprise wide data warehouse. In an independent data mart can be collected directly from sources. Question." What is star sche#a? Answer: ! st star ar sc sche hema ma is th the e si simp mple lest st fo form rm of da data ta wa warreho ehouse use sc schem hema a th that at consists of one or more dimensional and fact tables.

Question.$ What is snow a>e sche#a? Answer: ! Answer:  ! +nowake schema is nothing but one Fact table which is connected to a number of dimension tables$ he snowake and star schema are methods of storing data which are multidimensional in nature. n ature. Question.' What are 5/L /ools? Answer: ,L Answer:  ,L ools are stands for ,xtraction$ ransformation$ and Loading the data into the data warehouse for decision making. ,L refers to the methods involved in accessing and manipulating source data and loading it into target database. Question., What are Di#ensional table? Answer: Eimension tables contain attributes that describe fact records in the fact table. Question.0 What is data Modellin+? Answer: Eata Answer:  Eata Modeling is representing the real world set of data structures or entities and their relationship in their of data models$ required for a database.Eata Modelling consists of various types like 3onceptual data modeling Logical data modeling *hysical data modeling ,nterprise data modeling elation elatio n data modeling Eimensional data modeling. Question.4 What is &urro+ate >e)? Answer: +urrogate Answer:  +urrogate key is a substitution for the natural primary key. It is "ust a unique identi#er or number of each row that can be used for the primary key to the table. Question.1 What is Data Minin+? Answer: ! Eata Mining is the process of analy5ing data from diOerent perspectives and summari5ing it into useful information. Question.11 What is 7-erational Data &tore? Answer: ! Answer:  ! %E+ is an operational data store which comes as a second layer in a datawarehouse architecture. It has got the characteristics of both %L* and E++ systems. Question.12 What is the Diference between 7L/ and 7LA? Answer: %L %L* * is not nothin hing g but %nL %nLine ine ran ransac sactio tion n *r *roce ocessi ssing ng whi which ch co conta ntains ins a normalisedtables %nline !naltical *rogramming? contains the history of %L* data which is non-volatile acts as a Eecisions +upport +ystem. Question.13 (ow #an) t)-es o di#ensions are aailable in nor#atica? Answer: here Answer:  here are three three types of dimensions available available are H Punk dimension Eegenerative Eimension 3onformed Eimension

Question.1" What are the desi+ner tools or creatin+ tranor#ations? Answer: Mapping designer ransf ransformation ormation developer Mapplet designer Question.1$ What is the #a-let? Answer: Maplet Answer:  Maplet is a set of transformations that you build in the maplet designer and you can use in multiple mapings. Question. 1' What is &ession and atches? Answer: +essionH Answer:  +essionH ! session is a set of commands that describes the server to move data to the target.sessions$ ewent wait$ email$ command$ etc?. Question.1, What are slowl) chan+in+ di#ensions? Answer: Eim imen ensi sio ons th that at cha hang nge e ov over erti time me are ca call lled ed +lo low wly 3h 3han ang gin ing g Eimensions>+3E?. +lowly 3hanging Eimension-ype; H Chich has only current records. +lowly 3hanging Eimension-ypeB H Chich has current records records ] historical records. +lowly +low ly 3hang 3hanging ing Eimen Eimensionsion- ypeS H Chi Chich ch has cur curre rent nt re recor cords ds ] one pr previ evious ous records. Question.10 What are 2 #odes o data #oe#ent in nor#atica &erer? Answer: here Answer:  here are two modes of data movement areH &ormal Mode in which for every record a separate EML stmt will be prepared and executed.
Teradata Interview Questions and answers Question.1 What is the diference between FastLoad and MultiLoad? Answer: FastLoad uses multiple sessions to quickly load large amount of data on empty table. MultiLoad is used for high-volume maintenance on tables and views. It works with non-empty tables also. Maximum  tables can be used in MultiLoad. Question.2 Which is aster? Answer: FastLoad. Question.3 Diference between nner !oin and outer !oin?

Answer: !n inner "oin gets data from both tables where the speci#ed data exists in both tables. !n outer "oin gets data from the source table at all times$ and returns data from the outer "oined table %&L' if it matches the criteria.(sociallocker) Question." What is #ulti nsert? Answer: Inserting data records into the table using multiple insert statements. *utting a semi colon in front of the key word I&+, in the next statement rather than terminating the #rst statement with a semi colon achieves it. Insert into +ales /select 0 from customer1 Insert into Loan /select 0 from customer12 Question.$ s #ulti insert A%& standard? Answer: &o. Question.' (o (ow w do )o )ou u cr crea eate te a ta tabl ble e wi with th an e* e*is isti tin+ n+ st stru ruct ctur ure e o  another table with data and with no data? Answer: 3reate table 3ustomer dummy as 3ustomer with data 4 with no data2 Question., What is the o-enin+ ste- in asic /eradata /eradata Quer) scri-t? Answer: Logon tdipid4username$ password. Question.0    ou ou are callin+ a te scri-t which dro-s a table table and creates a table. t will throw an error i the table does not e*ist. (ow can )ou do it without throwin+ the error? Answer: ' Answer:  'ou ou can it by setting error level to 5ero before dropping and resetting the error level to 6 after dropping. Question.4 56676L585L 930,; Answer: +,7,I' 62 Question.1 e) b) -uttin+ eualit) on that >e)? Answer: &o. Question.11 Did )ou write stored -rocedures in /eradata? Answer: &o$ because they become a single amp operation and my company didn8t encourage that. Question.12 What is the use o hain+ inde*@s on table? Answer: For faster record search. Question.13 Did )ou use Quer) #an or &QL assistance? Answer: +9L assistant :.; Question.1".  a# u-dat u-datin in+ + a ta tabl ble e in t te e.. t ha has s to uu-da date te a la lar+ r+e e nu#ber o rows so it@s reall) slow. What do )ou su++est? Answer: In eradata eradata it is not recommended to update more than ; million rows due to "ournal space problems$ if it is less than that and it8s slow in the