informatica faq-9
80.When the informatica server marks that a batch is failed?
If one of session is configured to "run if previous completes" and that previous session fails.
81. What is a command that used to run a batch? pmcmd is used to start a batch.
82. What r the different options used to configure the sequential batches? Two options
Run the session only if previous session completes sucessfully. Always runs the session.
83. In a sequential batch can u run the session if previous session fails?
Yes.By setting the option always runs the session.
84. Can u start a batches with in a batch?
U can not. If u want to start batch that resides in a batch,create a new independent batch and copy the necessary sessions into the new batch.
85. Can u start a session inside a batch idividually?
We can start our required session only in case of sequential batch.in case of concurrent batch
we cant do like this.
86. How can u stop a batch? By using server manager or pmcmd.
87. What r the session parameters?
Session parameters r like maping parameters,represent values U might want to change between
sessions such as database connections or source files.
Server manager also allows U to create userdefined session parameters.Following r user defined
session parameters.
Database connections
Source file names: use this parameter when u want to change the name or location of
session source file between session runs
Target file name : Use this parameter when u want to change the name or location of
session target file between session runs.
Reject file name : Use this parameter when u want to change the name or location of
session reject files between session runs.
88. What is parameter file?
Parameter file is to define the values for parameters and variables used in a session.A parameter
file is a file created by text editor such as word pad or notepad.
U can define the following values in parameter file
Maping parameters
Maping variables
session parameters
89. How can u access the remote source into U'r session?
Relational source: To acess relational source which is situated in a remote place ,u need to
configure database connection to the datasource.
FileSource : To access the remote source file U must configure the FTP connection to the
host machine before u create the session.
Hetrogenous : When U'r maping contains more than one source type,the server manager creates
a hetrogenous session that displays source options for all types.
90. What is difference between partioning of relatonal target and partitioning of file targets?
If u parttion a session with a relational target informatica server creates multiple connections
to the target database to write target data concurently.If u partition a session with a file target
the informatica server creates one target file for each partition.U can configure session properties
to merge these target files.
91. what r the transformations that restricts the partitioning of sessions?
Advanced External procedure tranformation and External procedure transformation: This
transformation contains a check box on the properties tab to allow partitioning.
Aggregator Transformation: If u use sorted ports u can not parttion the assosiated source
Joiner Transformation : U can not partition the master source for a joiner transformation
Normalizer Transformation
XML targets.
92. Performance tuning in Informatica?
The goal of performance tuning is optimize session performance so sessions run during the available load window for the Informatica Server.Increase the session performance by following.
The performance of the Informatica Server is related to network connections. Data generally moves across a network at less than 1 MB per second, whereas a local disk moves data five to twenty times faster. Thus network connections ofteny affect on session performance.So aviod netwrok connections.
Flat files: If u'r flat files stored on a machine other than the informatca server, move those files to the machine that consists of informatica server.
Relational datasources: Minimize the connections to sources ,targets and informatica server to
improve session performance.Moving target database into server system may improve session
performance.
Staging areas: If u use staging areas u force informatica server to perform multiple datapasses.
Removing of staging areas may improve session performance.
U can run the multiple informatica servers againist the same repository.Distibuting the session load to multiple informatica servers may improve session performance.
Run the informatica server in ASCII datamovement mode improves the session performance.Because ASCII datamovement mode stores a character value in one byte.Unicode mode takes 2 bytes to store a character.
If a session joins multiple source tables in one Source Qualifier, optimizing the query may improve performance. Also, single table select statements with an ORDER BY or GROUP BY clause may benefit from optimization such as adding indexes.
We can improve the session performance by configuring the network packet size,which allows
data to cross the network at one time.To do this go to server manger ,choose server configure database connections.
If u r target consists key constraints and indexes u slow the loading of data.To improve the session performance in this case drop constraints and indexes before u run the session and rebuild them after completion of session.
Running a parallel sessions by using concurrent batches will also reduce the time of loading the
data.So concurent batches may also increase the session performance.
Partittionig the session improves the session performance by creating multiple connections to sources and targets and loads data in paralel pipe lines.
In some cases if a session contains a aggregator transformation ,u can use incremental aggregation to improve session performance.
Aviod transformation errors to improve the session performance.
If the sessioin containd lookup transformation u can improve the session performance by enabling the look up cache.
If U'r session contains filter transformation ,create that filter transformation nearer to the sources
or u can use filter condition in source qualifier.
Aggreagator,Rank and joiner transformation may oftenly decrease the session performance .Because they must group data before processing it.To improve session performance in this case use sorted ports option.
92. What is difference between maplet and reusable transformation?
Maplet consists of set of transformations that is reusable.A reusable transformation is a
single transformation that can be reusable.
If u create a variables or parameters in maplet that can not be used in another maping or maplet.Unlike the variables that r created in a reusable transformation can be usefull in any other maping or maplet.
We can not include source definitions in reusable transformations.But we can add sources to a maplet.
Whole transformation logic will be hided in case of maplet.But it is transparent in case of reusable transformation.
We cant use COBOL source qualifier,joiner,normalizer transformations in maplet.Where as we can make them as a reusable transformations.
93. Define informatica repository?
The Informatica repository is a relational database that stores information, or metadata, used by the Informatica Server and Client tools. Metadata can include information such as mappings describing how to transform source data, sessions indicating when you want the Informatica Server to perform the transformations, and connect strings for sources and targets.
The repository also stores administrative information such as usernames and passwords, permissions and privileges, and product version.
Use repository manager to create the repository.The Repository Manager connects to the repository database and runs the code needed to create the repository tables.Thsea tables
stores metadata in specific format the informatica server,client tools use.
94. What r the types of metadata that stores in repository?
Following r the types of metadata that stores in the repository
Database connections
Global objects
Mappings
Mapplets
Multidimensional metadata
Reusable transformations
Sessions and batches
Short cuts
Source definitions
Target defintions
Transformations
95. What is power center repository?
The PowerCenter repository allows you to share metadata across repositories to create a data mart domain. In a data mart domain, you can create a single global repository to store metadata used across an enterprise, and a number of local repositories to share the global metadata as needed.
96. How can u work with remote database in informatica?did u work directly by using remote
connections?
To work with remote datasource u need to connect it with remote connections.But it is not
preferable to work with that remote source directly by using remote connections .Instead u bring that source into U r local machine where informatica server resides.If u work directly with remote source the session performance will decreases by passing less amount of data across the network in a particular time.
97. What r the new features in Informatica 5.0?
U can Debug U'r maping in maping designer
U can view the work space over the entire screen
The designer displays a new icon for a invalid mapings in the navigator window
U can use a dynamic lookup cache in a lokup transformation
Create maping parameters or maping variables in a maping or maplet to make mapings more
flexible
U can export objects into repository and import objects from repository.when u export a repository object,the designer or server manager creates an XML file to describe the repository metadata.
The designer allows u to use Router transformation to test data for multiple conditions.Router transformation allows u route groups of data to transformation or target.
U can use XML data as a source or target.
Server Enahancements:
U can use the command line program pmcmd to specify a parameter file to run sessions or batches.This allows you to change the values of session parameters, and mapping parameters and variables at runtime.
If you run the Informatica Server on a symmetric multi-processing system, you can use multiple CPUs to process a session concurrently. You configure partitions in the session properties based on source qualifiers. The Informatica Server reads, transforms, and writes partitions of data in parallel for a single session. This is avialable for Power center only.
Informatica server creates two processes like loadmanager process,DTM process to run the sessions.
Metadata Reporter: It is a web based application which is used to run reports againist repository metadata.
U can copy the session across the folders and reposotories using the copy session wizard in the informatica server manager
With new email variables, you can configure post-session email to include information, such as the mapping used during the session
98. what is incremantal aggregation?
When using incremental aggregation, you apply captured changes in the source to aggregate calculations in a session. If the source changes only incrementally and you can capture changes, you can configure the session to process only those changes. This allows the Informatica Server to update your target incrementally, rather than forcing it to process the entire source and recalculate the same calculations each time you run the session.
99. What r the scheduling options to run a sesion?
U can shedule a session to run at a given time or intervel,or u can manually run the session.
Different options of scheduling
Run only on demand: server runs the session only when user starts session explicitly
Run once: Informatica server runs the session only once at a specified date and time.
Run every: Informatica server runs the session at regular intervels as u configured.
Customized repeat: Informatica server runs the session at the dats and times secified in the repeat dialog box.
If one of session is configured to "run if previous completes" and that previous session fails.
81. What is a command that used to run a batch? pmcmd is used to start a batch.
82. What r the different options used to configure the sequential batches? Two options
Run the session only if previous session completes sucessfully. Always runs the session.
83. In a sequential batch can u run the session if previous session fails?
Yes.By setting the option always runs the session.
84. Can u start a batches with in a batch?
U can not. If u want to start batch that resides in a batch,create a new independent batch and copy the necessary sessions into the new batch.
85. Can u start a session inside a batch idividually?
We can start our required session only in case of sequential batch.in case of concurrent batch
we cant do like this.
86. How can u stop a batch? By using server manager or pmcmd.
87. What r the session parameters?
Session parameters r like maping parameters,represent values U might want to change between
sessions such as database connections or source files.
Server manager also allows U to create userdefined session parameters.Following r user defined
session parameters.
Database connections
Source file names: use this parameter when u want to change the name or location of
session source file between session runs
Target file name : Use this parameter when u want to change the name or location of
session target file between session runs.
Reject file name : Use this parameter when u want to change the name or location of
session reject files between session runs.
88. What is parameter file?
Parameter file is to define the values for parameters and variables used in a session.A parameter
file is a file created by text editor such as word pad or notepad.
U can define the following values in parameter file
Maping parameters
Maping variables
session parameters
89. How can u access the remote source into U'r session?
Relational source: To acess relational source which is situated in a remote place ,u need to
configure database connection to the datasource.
FileSource : To access the remote source file U must configure the FTP connection to the
host machine before u create the session.
Hetrogenous : When U'r maping contains more than one source type,the server manager creates
a hetrogenous session that displays source options for all types.
90. What is difference between partioning of relatonal target and partitioning of file targets?
If u parttion a session with a relational target informatica server creates multiple connections
to the target database to write target data concurently.If u partition a session with a file target
the informatica server creates one target file for each partition.U can configure session properties
to merge these target files.
91. what r the transformations that restricts the partitioning of sessions?
Advanced External procedure tranformation and External procedure transformation: This
transformation contains a check box on the properties tab to allow partitioning.
Aggregator Transformation: If u use sorted ports u can not parttion the assosiated source
Joiner Transformation : U can not partition the master source for a joiner transformation
Normalizer Transformation
XML targets.
92. Performance tuning in Informatica?
The goal of performance tuning is optimize session performance so sessions run during the available load window for the Informatica Server.Increase the session performance by following.
The performance of the Informatica Server is related to network connections. Data generally moves across a network at less than 1 MB per second, whereas a local disk moves data five to twenty times faster. Thus network connections ofteny affect on session performance.So aviod netwrok connections.
Flat files: If u'r flat files stored on a machine other than the informatca server, move those files to the machine that consists of informatica server.
Relational datasources: Minimize the connections to sources ,targets and informatica server to
improve session performance.Moving target database into server system may improve session
performance.
Staging areas: If u use staging areas u force informatica server to perform multiple datapasses.
Removing of staging areas may improve session performance.
U can run the multiple informatica servers againist the same repository.Distibuting the session load to multiple informatica servers may improve session performance.
Run the informatica server in ASCII datamovement mode improves the session performance.Because ASCII datamovement mode stores a character value in one byte.Unicode mode takes 2 bytes to store a character.
If a session joins multiple source tables in one Source Qualifier, optimizing the query may improve performance. Also, single table select statements with an ORDER BY or GROUP BY clause may benefit from optimization such as adding indexes.
We can improve the session performance by configuring the network packet size,which allows
data to cross the network at one time.To do this go to server manger ,choose server configure database connections.
If u r target consists key constraints and indexes u slow the loading of data.To improve the session performance in this case drop constraints and indexes before u run the session and rebuild them after completion of session.
Running a parallel sessions by using concurrent batches will also reduce the time of loading the
data.So concurent batches may also increase the session performance.
Partittionig the session improves the session performance by creating multiple connections to sources and targets and loads data in paralel pipe lines.
In some cases if a session contains a aggregator transformation ,u can use incremental aggregation to improve session performance.
Aviod transformation errors to improve the session performance.
If the sessioin containd lookup transformation u can improve the session performance by enabling the look up cache.
If U'r session contains filter transformation ,create that filter transformation nearer to the sources
or u can use filter condition in source qualifier.
Aggreagator,Rank and joiner transformation may oftenly decrease the session performance .Because they must group data before processing it.To improve session performance in this case use sorted ports option.
92. What is difference between maplet and reusable transformation?
Maplet consists of set of transformations that is reusable.A reusable transformation is a
single transformation that can be reusable.
If u create a variables or parameters in maplet that can not be used in another maping or maplet.Unlike the variables that r created in a reusable transformation can be usefull in any other maping or maplet.
We can not include source definitions in reusable transformations.But we can add sources to a maplet.
Whole transformation logic will be hided in case of maplet.But it is transparent in case of reusable transformation.
We cant use COBOL source qualifier,joiner,normalizer transformations in maplet.Where as we can make them as a reusable transformations.
93. Define informatica repository?
The Informatica repository is a relational database that stores information, or metadata, used by the Informatica Server and Client tools. Metadata can include information such as mappings describing how to transform source data, sessions indicating when you want the Informatica Server to perform the transformations, and connect strings for sources and targets.
The repository also stores administrative information such as usernames and passwords, permissions and privileges, and product version.
Use repository manager to create the repository.The Repository Manager connects to the repository database and runs the code needed to create the repository tables.Thsea tables
stores metadata in specific format the informatica server,client tools use.
94. What r the types of metadata that stores in repository?
Following r the types of metadata that stores in the repository
Database connections
Global objects
Mappings
Mapplets
Multidimensional metadata
Reusable transformations
Sessions and batches
Short cuts
Source definitions
Target defintions
Transformations
95. What is power center repository?
The PowerCenter repository allows you to share metadata across repositories to create a data mart domain. In a data mart domain, you can create a single global repository to store metadata used across an enterprise, and a number of local repositories to share the global metadata as needed.
96. How can u work with remote database in informatica?did u work directly by using remote
connections?
To work with remote datasource u need to connect it with remote connections.But it is not
preferable to work with that remote source directly by using remote connections .Instead u bring that source into U r local machine where informatica server resides.If u work directly with remote source the session performance will decreases by passing less amount of data across the network in a particular time.
97. What r the new features in Informatica 5.0?
U can Debug U'r maping in maping designer
U can view the work space over the entire screen
The designer displays a new icon for a invalid mapings in the navigator window
U can use a dynamic lookup cache in a lokup transformation
Create maping parameters or maping variables in a maping or maplet to make mapings more
flexible
U can export objects into repository and import objects from repository.when u export a repository object,the designer or server manager creates an XML file to describe the repository metadata.
The designer allows u to use Router transformation to test data for multiple conditions.Router transformation allows u route groups of data to transformation or target.
U can use XML data as a source or target.
Server Enahancements:
U can use the command line program pmcmd to specify a parameter file to run sessions or batches.This allows you to change the values of session parameters, and mapping parameters and variables at runtime.
If you run the Informatica Server on a symmetric multi-processing system, you can use multiple CPUs to process a session concurrently. You configure partitions in the session properties based on source qualifiers. The Informatica Server reads, transforms, and writes partitions of data in parallel for a single session. This is avialable for Power center only.
Informatica server creates two processes like loadmanager process,DTM process to run the sessions.
Metadata Reporter: It is a web based application which is used to run reports againist repository metadata.
U can copy the session across the folders and reposotories using the copy session wizard in the informatica server manager
With new email variables, you can configure post-session email to include information, such as the mapping used during the session
98. what is incremantal aggregation?
When using incremental aggregation, you apply captured changes in the source to aggregate calculations in a session. If the source changes only incrementally and you can capture changes, you can configure the session to process only those changes. This allows the Informatica Server to update your target incrementally, rather than forcing it to process the entire source and recalculate the same calculations each time you run the session.
99. What r the scheduling options to run a sesion?
U can shedule a session to run at a given time or intervel,or u can manually run the session.
Different options of scheduling
Run only on demand: server runs the session only when user starts session explicitly
Run once: Informatica server runs the session only once at a specified date and time.
Run every: Informatica server runs the session at regular intervels as u configured.
Customized repeat: Informatica server runs the session at the dats and times secified in the repeat dialog box.
posted by dwhfaq | 11:07 AM
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