informaticafaq-6
20.How can U improve session performance in aggregator transformation? Use sorted input.
21.What is aggregate cache in aggregator transforamtion?
The aggregator stores data in the aggregate cache until it completes aggregate calculations.When u run a session that uses an aggregator transformation,the informatica server creates index and data caches in memory to process the transformation.If the informatica server requires more space,it stores overflow values in cache files.
22.What r the diffrence between joiner transformation and source qualifier transformation?
U can join hetrogenious data sources in joiner transformation which we can not achieve in source qualifier transformation.
U need matching keys to join two relational sources in source qualifier transformation.Where as u doesn't need matching keys to join two sources.
Two relational sources should come from same datasource in sourcequalifier.U can join relatinal sources which r coming from diffrent sources also.
23.In which condtions we can not use joiner transformation(Limitaions of joiner transformation)?
Both pipelines begin with the same original data source.
Both input pipelines originate from the same Source Qualifier transformation.
Both input pipelines originate from the same Normalizer transformation.
Both input pipelines originate from the same Joiner transformation.
Either input pipelines contains an Update Strategy transformation.
Either input pipelines contains a connected or unconnected Sequence Generator transformation.
24.what r the settiings that u use to cofigure the joiner transformation?
Master and detail source
Type of join
Condition of the join
25. What r the join types in joiner transformation?
Normal (Default)
Master outer
Detail outer
Full outer
26.What r the joiner caches?
When a Joiner transformation occurs in a session, the Informatica Server reads all the records from the master source and builds index and data caches based on the master rows.
After building the caches, the Joiner transformation reads records from the detail source and perform joins.
27.what is the look up transformation?
Use lookup transformation in u'r mapping to lookup data in a relational table,view,synonym.
Informatica server queries the look up table based on the lookup ports in the transformation.It compares the lookup transformation port values to lookup table column values based on the look up condition.
28.Why use the lookup transformation ?
To perform the following tasks.
Get a related value. For example, if your source table includes employee ID, but you want to include the employee name in your target table to make your summary data easier to read.
Perform a calculation. Many normalized tables include values used in a calculation, such as gross sales per invoice or sales tax, but not the calculated value (such as net sales).
Update slowly changing dimension tables. You can use a Lookup transformation to determine whether records already exist in the target.
29.What r the types of lookup? Connected and unconnected
30.Differences between connected and unconnected lookup?
Connected lookup Unconnected lookup
Receives input values diectly from Receives input values from the result of a
the pipe line. lkp expression in a another transformation.
U can use a dynamic or static cache U can use a static cache.
Cache includes all lookup columns Cache includes all lookup out put ports in the
used in the maping lookup condition and the lookup/return port.
Support user defined default values Does not support user defiend default values
31.what is meant by lookup caches?
The informatica server builds a cache in memory when it processes the first row af a data in a cached look up transformation.It allocates memory for the cache based on the amount u configure in the transformation or session properties.The informatica server stores condition values in the index cache and output values in the data cache.
32.What r the types of lookup caches?
Persistent cache: U can save the lookup cache files and reuse them the next time the informatica server processes a lookup transformation configured to use the cache.
Recache from database: If the persistent cache is not synchronized with he lookup table,U can configure the lookup transformation to rebuild the lookup cache.
Static cache: U can configure a static or readonly cache for only lookup table.By default informatica server creates a static cache.It caches the lookup table and lookup values in the cache for each row that comes into the transformation.when the lookup condition is true,the informatica server does not update the cache while it prosesses the lookup transformation.
Dynamic cache: If u want to cache the target table and insert new rows into cache and the target,u can create a look up transformation to use dynamic cache.The informatica server dynamically inerts data to the target table.
shared cache: U can share the lookup cache between multiple transactions.U can share unnamed cache between transformations inthe same maping.
33. Difference between static cache and dynamic cache
Static cache Dynamic cache
U can not inert or update the cache. U can insert rows into the cache as u pass
to the target
The informatic server returns a value from The informatic server inserts rows into cache
the lookup table opr cache when the condition when the condition is false.This indicates that
is true.When the condition is not true,the the row is not in the cache or target table.
informatica server returns the default value U can pass these rows to the target table.
for connected transformations and null for
unconnected transformations.
34.Which transformation should we use to normalize the COBOL and relational sources?
Normalizer Transformation.
When U drag the COBOL source in to the mapping Designer workspace,the normalizer transformation automatically appears,creating input and output ports for every column in the source.
35.How the informatica server sorts the string values in Ranktransformation?
When the informatica server runs in the ASCII data movement mode it sorts session data using Binary sortorder.If U configure the seeion to use a binary sort order,the informatica server caluculates the binary value of each string and returns the specified number of rows with the higest binary values for the string.
36.What r the rank caches?
During the session ,the informatica server compares an inout row with rows in the datacache.If the input row out-ranks a stored row,the informatica server replaces the stored row with the input row.The informatica server stores group information in an index cache and row data in a data cache.
37.What is the Rankindex in Ranktransformation?
The Designer automatically creates a RANKINDEX port for each Rank transformation. The Informatica Server uses the Rank Index port to store the ranking position for each record in a group. For example, if you create a Rank transformation that ranks the top 5 salespersons for each quarter, the rank index numbers the salespeople from 1 to 5:
38.What is the Router transformation?
A Router transformation is similar to a Filter transformation because both transformations allow you to use a condition to test data. However, a Filter transformation tests data for one condition and drops the rows of data that do not meet the condition. A Router transformation tests data for one or more conditions and gives you the option to route rows of data that do not meet any of the conditions to a default output group.
If you need to test the same input data based on multiple conditions, use a Router Transformation in a mapping instead of creating multiple Filter transformations to perform the same task.
39.What r the types of groups in Router transformation?
Input group Output group
The designer copies property information from the input ports of the input group to create a set of output ports for each output group.
Two types of output groups
User defined groups
Default group
U can not modify or delete default groups.
21.What is aggregate cache in aggregator transforamtion?
The aggregator stores data in the aggregate cache until it completes aggregate calculations.When u run a session that uses an aggregator transformation,the informatica server creates index and data caches in memory to process the transformation.If the informatica server requires more space,it stores overflow values in cache files.
22.What r the diffrence between joiner transformation and source qualifier transformation?
U can join hetrogenious data sources in joiner transformation which we can not achieve in source qualifier transformation.
U need matching keys to join two relational sources in source qualifier transformation.Where as u doesn't need matching keys to join two sources.
Two relational sources should come from same datasource in sourcequalifier.U can join relatinal sources which r coming from diffrent sources also.
23.In which condtions we can not use joiner transformation(Limitaions of joiner transformation)?
Both pipelines begin with the same original data source.
Both input pipelines originate from the same Source Qualifier transformation.
Both input pipelines originate from the same Normalizer transformation.
Both input pipelines originate from the same Joiner transformation.
Either input pipelines contains an Update Strategy transformation.
Either input pipelines contains a connected or unconnected Sequence Generator transformation.
24.what r the settiings that u use to cofigure the joiner transformation?
Master and detail source
Type of join
Condition of the join
25. What r the join types in joiner transformation?
Normal (Default)
Master outer
Detail outer
Full outer
26.What r the joiner caches?
When a Joiner transformation occurs in a session, the Informatica Server reads all the records from the master source and builds index and data caches based on the master rows.
After building the caches, the Joiner transformation reads records from the detail source and perform joins.
27.what is the look up transformation?
Use lookup transformation in u'r mapping to lookup data in a relational table,view,synonym.
Informatica server queries the look up table based on the lookup ports in the transformation.It compares the lookup transformation port values to lookup table column values based on the look up condition.
28.Why use the lookup transformation ?
To perform the following tasks.
Get a related value. For example, if your source table includes employee ID, but you want to include the employee name in your target table to make your summary data easier to read.
Perform a calculation. Many normalized tables include values used in a calculation, such as gross sales per invoice or sales tax, but not the calculated value (such as net sales).
Update slowly changing dimension tables. You can use a Lookup transformation to determine whether records already exist in the target.
29.What r the types of lookup? Connected and unconnected
30.Differences between connected and unconnected lookup?
Connected lookup Unconnected lookup
Receives input values diectly from Receives input values from the result of a
the pipe line. lkp expression in a another transformation.
U can use a dynamic or static cache U can use a static cache.
Cache includes all lookup columns Cache includes all lookup out put ports in the
used in the maping lookup condition and the lookup/return port.
Support user defined default values Does not support user defiend default values
31.what is meant by lookup caches?
The informatica server builds a cache in memory when it processes the first row af a data in a cached look up transformation.It allocates memory for the cache based on the amount u configure in the transformation or session properties.The informatica server stores condition values in the index cache and output values in the data cache.
32.What r the types of lookup caches?
Persistent cache: U can save the lookup cache files and reuse them the next time the informatica server processes a lookup transformation configured to use the cache.
Recache from database: If the persistent cache is not synchronized with he lookup table,U can configure the lookup transformation to rebuild the lookup cache.
Static cache: U can configure a static or readonly cache for only lookup table.By default informatica server creates a static cache.It caches the lookup table and lookup values in the cache for each row that comes into the transformation.when the lookup condition is true,the informatica server does not update the cache while it prosesses the lookup transformation.
Dynamic cache: If u want to cache the target table and insert new rows into cache and the target,u can create a look up transformation to use dynamic cache.The informatica server dynamically inerts data to the target table.
shared cache: U can share the lookup cache between multiple transactions.U can share unnamed cache between transformations inthe same maping.
33. Difference between static cache and dynamic cache
Static cache Dynamic cache
U can not inert or update the cache. U can insert rows into the cache as u pass
to the target
The informatic server returns a value from The informatic server inserts rows into cache
the lookup table opr cache when the condition when the condition is false.This indicates that
is true.When the condition is not true,the the row is not in the cache or target table.
informatica server returns the default value U can pass these rows to the target table.
for connected transformations and null for
unconnected transformations.
34.Which transformation should we use to normalize the COBOL and relational sources?
Normalizer Transformation.
When U drag the COBOL source in to the mapping Designer workspace,the normalizer transformation automatically appears,creating input and output ports for every column in the source.
35.How the informatica server sorts the string values in Ranktransformation?
When the informatica server runs in the ASCII data movement mode it sorts session data using Binary sortorder.If U configure the seeion to use a binary sort order,the informatica server caluculates the binary value of each string and returns the specified number of rows with the higest binary values for the string.
36.What r the rank caches?
During the session ,the informatica server compares an inout row with rows in the datacache.If the input row out-ranks a stored row,the informatica server replaces the stored row with the input row.The informatica server stores group information in an index cache and row data in a data cache.
37.What is the Rankindex in Ranktransformation?
The Designer automatically creates a RANKINDEX port for each Rank transformation. The Informatica Server uses the Rank Index port to store the ranking position for each record in a group. For example, if you create a Rank transformation that ranks the top 5 salespersons for each quarter, the rank index numbers the salespeople from 1 to 5:
38.What is the Router transformation?
A Router transformation is similar to a Filter transformation because both transformations allow you to use a condition to test data. However, a Filter transformation tests data for one condition and drops the rows of data that do not meet the condition. A Router transformation tests data for one or more conditions and gives you the option to route rows of data that do not meet any of the conditions to a default output group.
If you need to test the same input data based on multiple conditions, use a Router Transformation in a mapping instead of creating multiple Filter transformations to perform the same task.
39.What r the types of groups in Router transformation?
Input group Output group
The designer copies property information from the input ports of the input group to create a set of output ports for each output group.
Two types of output groups
User defined groups
Default group
U can not modify or delete default groups.
posted by dwhfaq | 11:00 AM
0 Comments:
Post a Comment
<< Home