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What is a Source Qualifier?
It represents all data queried from the source.
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sprajarajan- Member Since Mar-2008 | Aug 8th, 2008
Source Qualifier Is the default Transformation.
Through The source Qualifier Transformation Informatica Reads The Data.
We can Filter The Data.
We can sort the Data.
Its also Used to Join Homogeneous Source systems.
We can Join Any number of Sources in Singlae Source Qualifier.
We Can't Join the Flatfiles In sourcequalifier Because Flatfiles Are Heterogeneous When we open the Flatfiles At sourcequalifier At the time All The options are Disabled.joyfun23
- Jan 26th, 2010
1. Source Qualifier is the most important transformation which convert the source data type in to compatible NATIVE datatype of a mapping.2. Without a SQ a mapping can not be created,?after extractio...
venkat224
- Dec 24th, 2009
Source Qualifier is one of the transformations, which converts any type of data to the relational format. So that, can easily be used for any of the operations on the data.
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What is Data Transformation Manager?
After the load manager performs validations for the session, it creates the DTM process. The DTM process is the second process associated with the session run. The primary purpose of the DTM process is to create and manage threads that carry out the session tasks.· The DTM allocates process memory for the session and divide it into buffers. This is also known as buffer memory. It creates the main thread,...
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Goush- Member Since May-2007 | May 15th, 2007
When the workflow reaches a session, the Integration Service process starts
the DTM process. The DTM is the process associated with the session and it
performs the following tasks:
1. Retrieves and validates session information from the repository.
2. Performs pushdown optimization when the session is configured for
pushdown optimization.
3. Adds partitions to the session when the session is configured for dynamic
partitioning.
4. Forms partition groups when the session is configured to run on a grid.
5. Expands the service process variables, session, and mapping variables and
parameters.
6. Creates the session log.
7. Validates source and target code pages.
8. Verifies connection object permissions.
9. Runs pre-session shell commands, stored procedures and SQL.
10. Sends a request to start worker DTM processes on other nodes when the
session is configured to run on a grid.
11. Creates and runs mapping, reader, writer, and transformation threads to
extract, transform, and load data.
12. Runs post-session stored procedures, SQL, and shell commands
13. Sends post-session email.
jayapraveen
- Oct 4th, 2010
load manager creates the DTM(data transformation manager)in the work flow manager by the informatica server ,here DTM creates two threads 1.reader thread2.writer threadDTM reads the data from &nb...
chandrarekha
- Sep 6th, 2007
Load manager and DTM are the components of Informatica server. Load manager manages the load on the server by maintaining a queue of sessions and release the session based on first come and firs...
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Discuss the advantages & Disadvantages of star & snowflake schema?
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Answered by: swati
- Nov 5th, 2005
star schema consists of single fact table surrounded by some dimensional table.In snowflake schema the dimension tables are connected with some subdimension table.
In starflake dimensional ables r denormalized,in snowflake dimension tables r normalized.
star schema is used for report generation ,snowflake schema is used for cube.
The advantage of snowflake schema is that the normalized tables r easier to maintain.it also saves the storage space.
The disadvantage of snowflake schema is that it reduces the effectiveness of navigation across the tables due to large no of joins between them.
halgai
- Oct 8th, 2007
Snowflakes are an addition to the Kimball Dimensional system to enable that system to handle hierarchial data. When Kimball proposed the dimensional data warehouse it was not first recogonized t...
Richard
- Feb 2nd, 2006
It depends upon the clients which they are following, whether snowflake or star schema.
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What are Target Types on the Server?
Target Types are File, Relational and ERP.
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manojkumar_dwh- Member Since Apr-2007 | Apr 14th, 2007
PowerCenter can load data into the following targets:
- Relational. Oracle, Sybase, Sybase IQ, Informix, IBM DB2, Microsoft SQL Server, and Teradata.
- File. Fixed and delimited flat file and XML.
- Application. You can purchase additional PowerCenter Connect products to load data into SAP BW. You can also load data into IBM MQSeries message queues and TIBCO.
- Other. Microsoft Access.
You can load data into targets using ODBC or native drivers, FTP, or external loaders.
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What are Aggregate transformation?
Aggregator transformation allows you to perform aggregate calculations, such as averages and sums.
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Answered by: Praveen vasudev
- Sep 12th, 2005
Aggregator transform is m uch like the Group by clause in traditional SQL.
this particular transform is a connected/active transform which can take the incoming data form the mapping pipeline and group them based on the group by ports specified and can caculated aggregate funtions like ( avg, sum, count, stddev....e.tc) for each of those groups.
From a performanace perspective if your mapping has an AGGREGATOR transform use filters and sorters very early in the pipeline if there is any need for them.
veepee
sivakp
- Mar 13th, 2011
1. Aggrigator transformation allows to perform aggrigate calculation, such as SUM, MAX, MIN, FIRST, LAST2. Aggrigator transformation allows to perform aggrigate calculation of group.
shr_4
- Oct 27th, 2010
To perform Group by calculations we use Aggregator Transformation.It perform calculations similar to Expression Transformation.But difference between both is that Aggregator Transform...
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What is Load Manager?
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Answered by: Deb
- Jun 8th, 2005
I am providing the answer which I have taken it from Informatica 7.1.1 manual,
Ans: While running a Workflow,the PowerCenter Server uses the Load Manager process and the Data Transformation Manager Process (DTM) to run the workflow and carry out workflow tasks.When the PowerCenter Server runs a workflow, the Load Manager performs the following tasks:
1. Locks the workflow and reads workflow properties.
2. Reads the parameter file and expands workflow variables.
3. Creates the workflow log file.
4. Runs workflow tasks.
5. Distributes sessions to worker servers.
6. Starts the DTM to run sessions.
7. Runs sessions from master servers.
8. Sends post-session email if the DTM terminates abnormally.
When the PowerCenter Server runs a session, the DTM performs the following tasks:
1. Fetches session and mapping metadata from the repository.
2. Creates and expands session variables.
3. Creates the session log file.
4. Validates session code pages if data code page validation is enabled. Checks query
conversions if data code page validation is disabled.
5. Verifies connection object permissions.
6. Runs pre-session shell commands.
7. Runs pre-session stored procedures and SQL.
8. Creates and runs mapping, reader, writer, and transformation threads to extract,transform, and load data.
9. Runs post-session stored procedures and SQL.
10. Runs post-session shell commands.
11. Sends post-session email.raju4dw
- Aug 6th, 2010
Load Manager is responsible for dispatching the sessions and maintains Q of sessions based on first in and first out. Load Manager is also known as Master Processor (DTM) Data Transformation Manager.D...
Deb
- Jun 8th, 2005
I am providing the answer which I have taken it from Informatica 7.1.1 manual, Ans: While running a Workflow,the PowerCenter Server uses the Load Manager process and the Data Transformation...
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How do you identify existing rows of data in the target table using lookup transformation
Can identify existing rows of data using unconnected lookup transformation.
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Answered by: SK
- Aug 30th, 2007
There are two ways to lookup the target table to verify a row exists or not :
1. Use connect dynamic cache lookup and then check the values of NewLookuprow Output port to decide whether the incoming record already exists in the table / cache or not.
2. Use Unconnected lookup and call it from an expression trasformation and check the Lookup condition port value (Null/ Not Null) to decide whether the incoming record already exists in the table or not.doppalpaudi
- Jul 9th, 2010
Lookup Transformation is used to cheek weather the data is present in target or not.This transformation is of 2 types 1. Connected lookup transformation2. Unconnected lookup transformation.By using above both we can cheek the target for data .
svivekananda
- Jun 26th, 2010
We can use both connected and unconnected lookups to check the existing records in the target table.
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Mapplet Transformations
What are the transformations not used in mapplet and why?
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gazulas- Member Since Jan-2006 | Jul 2nd, 2008
The following should not include in a mapplet.
- Normalizer transformations
- Cobol sources
- XML Source Qualifier transformations
- XML sources
- Target definitions
- Pre- and post- session stored procedures
- Other mapplets
The exact reason i why these should not used i dont know.
sahan
- Jul 16th, 2009
Normalizer transformationXML source qualifierXML filesOther targets.If
you need to use sequence generator transformation use the reusable sequence gen t/rIf
you need to use stored procedure transformation, make the stored procedure type as normal. -
How many ways you can update a relational source definition ?
Two ways 1. Edit the definition 2. Reimport the defintion
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Sumithav29- Member Since Jun-2009 | Jun 12th, 2009
1. If you want to make minor changes to the source definition, you can edit the source definition (in source analyzer) then the Designer propagates the changes to all mappings using that source.
2. If the source changes are significant, re-import the source and giving replace option while re-importing will reflect the changes in all the mappings where the source is used.Sumithav29
- Jun 12th, 2009
1. If you want to make minor changes to the source definition, you can edit the source definition (in source analyzer) then the Designer propagates the changes to all mappings using that source.2. If ...
gazulas
- Jan 30th, 2006
in 2 ways we can do it 1) by reimport the source definition 2) by edit the source definition
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What is granularity in INFORMATICA? How should be the level of granularity for a fact table as well as for a dimension table?
P.Sivakumar
- Sep 12th, 2007
Granularity is a lowest level of information stored in databse that is called as granularity.
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Informatica Interview Questions
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