Question { Dmss, 12888 }

How to improve the performance of Aggregate
transformation?

Answer

1.Use sorted data and enable option 'sorted i/p'
2.By using incremental aggregation
3.group by simple columns like numeric columns
4.use filter transformation before aggregator to avoid
unnecessary aggregation on unwanted columns.

Question { Wipro, 24289 }

what is the difference between static and dynamic

Answer

static cache:

1.static cache remains same during the session run
2.static can be used to relational and falt file lookup
types
3.static cache can be used to both unconnected and
connected lookup transformation
4.we can handle multiple matches in static cache
5.we can use other than relational operators like <,>,<=,>=
&=

Dynamic cache:

1.dynamic cache changes durig session run
2.dynamic cache can be used to only relational lookup types
3.Dynamic cache can be used to only connetced lookups
4.we cannot multiple matches in dynamic cache
5.we can use only = operator with dynamic cache.

Question { Wipro, 24289 }

what is the difference between static and dynamic

Answer

there is a correction in dynamic cache: 3rd point

dynamic cache can be used to unconnected tr.provided
unconnected lkp based on relational type.

Question { CTS, 28372 }

how to load only the first and last record of a flat file
into the target?

Answer

we will get the result with answer # 4

Question { HSBC, 20644 }

if we r using aggregator we enabled sorted input but the
records r not sorted what happen?

Answer

If u enable the 'sorted I/p'option in AGG tranformation,
power center server assumes that all data is sorted by
group.
If u use sorted i/p and dont use the sorted data session
fails.

Question { HSBC, 20383 }

we r using aggregator with out using groupby?

Answer

answer #1 is correct

Question { 11206 }

How will you display "Mr" for male & "Mrs" for female in
target table?

Answer

Here the question is to just display value 'MR'for
males 'MR'for males , not to modify the data in the table
as 'MR'for males 'MR'for males

we can do it by many ways, one among those ........

select decode(column_name, 'male','MR','female','MRS')

this query displays MR for all males and MRS for all females

Question { 17528 }

Hi can any one tell me the difference between persistence
and dynamic caches? On which conditions we are using these
caches?

Answer

few more additions to the above answer.....

1.Dynamic lookup allows to modify cache where as
persistentlookup does not allow us to modify cache.

2.Dynamic lookup use 'newlookup row', a default port in the
cache but persistent does use any default ports in cache.

3.As session completes dynamic cache removed but the
persistent cache saved in informatica power centre server.

Question { BirlaSoft, 13856 }

I have Employee table, 10 cols are connected to next
transformation, only 4 cols are selected in SQL override.
What would be passed to next col.

Answer

no rows from the source qualifier transformation.It gives
an error like" query should return exactly 10 fields to
match fields projected from the source qualifier." .
Because number of rows selected in sql override must eqal
to number of rows connected to the next transformation from
source qulifier.

Question { BirlaSoft, 13856 }

I have Employee table, 10 cols are connected to next
transformation, only 4 cols are selected in SQL override.
What would be passed to next col.

Answer

few more addition to the above answer......

If you ignore to validate sql query in source qualifier
transformation mapping validates but at workflow level
sessiom fails with as error"variable not in select
list......."

Question { Wipro, 16150 }

What are set operators in Oracle

Answer

fOLLOWING are the set operators in oracle
UNION
UNION ALL
MINUS
INTERSECT

Question { Deloitte, 17318 }

How to create a mapping ?

id date
101 2/4/2008
101 4/4/2008
102 6/4/2008
102 4/4/2008
103 4/4/2008
104 8/4/2008

O/P - shud have only one id with the min(date)
How to create a mapping for this

Answer

Hi Achoudhr,

here u go,

sq--->agg----->target

In agg dont use group by on any port and take output
columns for both id & date ports, use 'min' function in
outpput expression and connect output ports to desired
target columns.you will get only one output row that is 101
2/4/2008.

note: if u use group by mapping outputs 3 rows.

Question { Patni, 17434 }

What is Target Update Override? What is the Use ?

Answer

Thaks Srinu & Himanshu for posting answers.

Question { Infotech, 35059 }

Please explain in detail with example about
1.Confirmed Dimension.
2.Junk Dimension.
3.Degenerated Dimension.
4.Slowly changing Dimensions

Answer

Few more additions to the above answers.....

Confirmed dimension: Dimesion which can be 100 % sharable
with other star schemas. In other terms it is connected to
more than one one fact table .

Ex: time dimension

Junk dimesion: stores low cordinality values (repeated
values),flagged values.
Ex: details of gender information(male/female)

Degenerated Dimension:The attribute in the fact table
directly comes from the source table not from any
dimensions called degenerated dimensions. these are also
called neither a dimension nor a perfect fact.

Ex:attribute order_no, comes from source

Slowly changing Dimensions:Dimesions which are changing
over a period of time called slowly changing dimensions.

Ex:salary of employee.

Question { CTS, 44087 }

What is ThroughPut in Informatica, How it works, Where I
can find this option to check ?

Answer

thoughtput is the rate at which power centre server read
the rows in bytes from source or write the rows in bytes
into the target per second.

U can find this option in workflow monitor.
right click on session choose properties and transformation
statictics tab u can find thoughtput details fro each
instance of source and target.