Interview Questions Answers in Informatica

Questions / { rayudu }

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Answers / { rayudu }

Which one is better performance wise connected/un-connected
lkp?why?

Answer

Connected lookup is used to lookup on each and every row
bjut unconnected lookup is used to lookup only when the
condition is true i,e unconnetcec is used only for selectetd
rows so obviously unconnected is faster .

Regards,
rayudu.

Is This Answer Correct ?

18 Yes

3 No

Question { Syntel, 21303 }

Can we insert and update a target table without using update
strategy transformation?How?

Answer

Yes By default if we wont use update stratagey t/r it will
insert the record by default .And if we want to update
without using update stratagey give the property UPDATE for
TreatSource rows at session level and in target properties
give updateas Update so that we can update without using UPD
T/r.

Regards,
rayudu.

Is This Answer Correct ?

10 Yes

2 No

Question { Syntel, 7688 }

Can any one describe what is audit table briefly?how does it
look like
and what are the columns in it?

Answer

Audit Table is nothing but the table which contains abouut
your workflow names and session names .It contains
information abt workflow and session status and their details.

Regards,
rayudu

Is This Answer Correct ?

4 Yes

0 No

Question { Syntel, 7688 }

Can any one describe what is audit table briefly?how does it
look like
and what are the columns in it?

Answer

WKFL_RUN_ID
WKFL_NME
START_TMST
END_TMST
ROW_INSERT_CNT
ROW_UPDATE_CNT
ROW_DELETE_CNT
ROW_REJECT_CNT

Above are the some of the sample columns

regards,
rayudu

Is This Answer Correct ?

0 Yes

0 No

Question { TCS, 8363 }

When will u go for Dynamic Cache and Persistent Cache? Pls
explain with an example?

Answer

If the lookup cache doesnt change between mutiple runs and
if we know that the lookup data doesnt change then we will
go for Persistant cache.

If the loopup cache changes between multiple session runs
and to keep the target table and lookup cache synchronized
we will use dynamic lookup cache .

regards,
rayudu.

Is This Answer Correct ?

7 Yes

4 No

Question { 6776 }

When will u go for (which means situation) Connected Lookup and Connected Lookup? Pls explain with an example?

Answer

When we want to return multiple ports from a mapping we wil
use connected lookup.

An connected lookup returns only one port from the t/r. If
we want to use lookup multiple times in a mapping and if we
want to lookup data only when the condition is true we will
use unconnected lookup. (if we dont want to look up all the
records and only some records)

regards,
rayudu

Is This Answer Correct ?

2 Yes

3 No

Question { IBM, 15768 }

Why do flat file load is faster if you compare that with
table load ?
Please answer me.

Advance Thanks,
Manojkumar

Answer

hi,

Flat file doesn't contain any indexes or keys so it will
directly load into it. whereas in a table it will first
check for indexes and keys while loading into table so it is
slow when compared to flat file loading.

Regards,
rayudu.

Is This Answer Correct ?

4 Yes

1 No

Question { IBM, 15768 }

Why do flat file load is faster if you compare that with
table load ?
Please answer me.

Advance Thanks,
Manojkumar

Answer

another reason is that when we load the data into table
integration service also verifies data type and will do
parsing if needed. But in case of flat file there is no need
of parsing and checking data types.

Is This Answer Correct ?

3 Yes

1 No

Question { IBM, 15768 }

Why do flat file load is faster if you compare that with
table load ?
Please answer me.

Advance Thanks,
Manojkumar

Answer

One more thing is while loading the data into table
,informatica writes the data into database logs before
loading into target ,and this cant be done while loading a
flat file.

Is This Answer Correct ?

7 Yes

1 No

Question { 5511 }

What are the types of error logs available in Informatica?

Answer

There are two types of error logs
1.Relational error logs.
2.File Error logs.

Rgds,
rayudu

Is This Answer Correct ?

1 Yes

0 No

Question { 4112 }

Define error Threshold?

Answer

The number of errors at which the integration service stops the session .The value which we will give to stop the session
is called error threshold value

Is This Answer Correct ?

3 Yes

0 No

Question { Cap Gemini, 20737 }

Examples of Fatal & Non-Fatal error?

Answer

Non-Fatal_Errors are the errors that doesnot force the session to stop when it encounters errors .

Fatal Errors are the errors that occurs when the connections to source ,targets and to the database is failed .

Rgds,
rayudu

Is This Answer Correct ?

19 Yes

2 No

Question { 6190 }

My source contains 10 records with 5 columns.What happens if I
select group by all columns in Aggregator T/R?

Answer

If you select groupby on all the ports you will get distinct records only.

Is This Answer Correct ?

22 Yes

0 No

Question { 5917 }

i have two coloumn
emp_no sal
1 3000
2 3000
3 3000
4 4000
5 5000
6 2700
7 4500
i just need output by removing duplicate.my answer should be
emp_no sal
1 3000
2 4000
3 5000
and so on.please tel me the transformation to use and if variable is used in expression then how can i give variable expression

Answer

First in the pre_session command task remove the duplicates
using the following

cut -d "," -f2 filename|uniq

Now in the file you will have

3000
4000
5000
2700
4500

now after source qualifier keep a expression and generate
the sequence.

Hope it clarifies

Regards,
rayudu

Is This Answer Correct ?

3 Yes

0 No

Question { Cap Gemini, 11340 }

in my source table one of column contains the data like
vishnraju@gmail.com,suresh@yahoo.com,krishna@hotmail.com these
records i need to send in target table as below format.
vishnuraju,suresh,krishna

Answer

HI ,

By using substr and instr we can retrive only the name part from the entire string and send to target.

Regrds,
rayudu

Is This Answer Correct ?

8 Yes

2 No