Tuesday, February 19, 2008

Informatica Frequently asked questions with answers

Sl. No. Subject Complexity Questions Answers
1 Informatica simple What is sql override ? Overriding a SQL in source qualifier or lookup for additional logic.
2 Informatica simple Can we have multiple conditions in a Lookup? Yes
3 Informatica simple Can we have multiple conditions in a Filter? Yes
4 Informatica simple How the flags are called in Update strategy? 0 - DD_INSERT , 1- DD_UPDATE , 2- DD_DELETE , 3- DD_REJECT
5 Informatica simple Is it possible to run the session other than Server manager? If so how? YES USING PMCMD
6 Informatica simple What is diff. Things u can do using PMCMD? Start, Stop and abort the session
7 Informatica average/simple What is the use of power plug? For 3rd party connectors to sap, mainframe, Peoplesoft
8 Informatica average/simple What kind of Test plan? What kind of validation you do? In Informatica we create some test SQL to compare the number or records and validate scripts if the data in the warehouse is loaded for the logic incorporated.
9 Informatica simple What is the usage of unconnected/connected look up? We use a lookup for connecting to a table in the source or a target. There are 2 ways in which a lookup can be configured i.e. connected or unconnected
10 Informatica simple What is the difference between Connected and Unconnected Lookups ? Connected Lookup Receives input values directly from the pipeline. Unconnected Lookup Receives input values from the result of a :LKP expression in another transformation. Connected Lookup You can use a dynamic or static cache. Unconnected Lookup You can use a static cache. Connected Lookup Cache includes all lookup columns used in the mapping (that is, lookup table columns included in the lookup condition and lookup table columns linked as output ports to other transformations). Unconnected Lookup Cache includes all lookup/output ports in the lookup condition and the lookup/return port.Connected Lookup Can return multiple columns from the same row or insert into the dynamic lookup cache. Unconnected Lookup The dynamic lookup cache, Designate one return port (R). Returns one column from each row. Connected Lookup If there is no match for the lookup condition, the Informatica Server returns the default value for all output ports. If you configure dynamic caching, the Informatica Server inserts rows into the cache. Unconnected Lookup If there is no match for the lookup condition, the Informatica Server returns NULL. Connected Lookup Pass multiple output values to another transformation. Link lookup/output ports to another transformation. Unconnected Lookup Pass one output value to another transformation. The lookup/output/return port passes the value to the transformation calling: LKP expression.Connected Lookup Supports user-defined default values. Unconnected Lookup Does not support user-defined default values
11 Informatica simple If u have data coming from diff. sources what transformation will u use in your designer? Joiner Transformation
12 Informatica simple What are different ports in Informatica? Input, Output, Variable, Return/Rank, Lookup and Master.
13 Informatica simple What is a Variable port? Why it is used? Variable port is used to store intermediate results. Variable ports can reference input ports and variable ports, but not output ports.
14 Informatica average Diff between Active and passive transormation ? "Transf can be active or passive , activ tranf can change the no of rec passed th it, a passive tranf can never change the rec cnt, Active trsnf that might change the rec cnt are advan ext proc, aggrega, filter,joiner,normalizer, rank , updte strategy, source qualifier, if u use powerconnect to access erp sources, erp source quail is also an active tranfor
Passive tranf :- lookup, expression, external procedure, seq generator, stored procedure
U can connect only 1 active tranf to the same tranf or target can connect any no of pass tranf
"
15 Informatica simple What are Mapplet? A mapplet is a reusable object that represents a set of transformations. It allows you to reuse transformation logic and can contain as many transformation as you need.
16 Informatica simple What is Aggregate transformation An aggregator transformation allows you to perform aggregate calculations, such as average and sums. The Aggregator transformation is unlike the Expression transformation, in that you can use the Aggregator transformation to perform calculations on groups.
17 Informatica simple What is Router Transformation? How is it different from Filter transformation? A Router transformation is similar to a Filter transformation because both transformations allow you to use a condition to test data. A Filter transformation tests data for one condition and drops the rows of data that do not meet the condition. However, 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 default output group.
18 Informatica simple What are connected and unconnected transformations? "Connected transformations are the transformation, which are in the data flow, whereas unconnected transformation will not be in the data flow.
These are dealt in Lookup and Stored procedure transformations.
"
19 Informatica simple What is Normalizer transformation? Normalizer transformation normalizes records from COBOL and relational sources allowing you to organize the data according to your needs. A normalizer transformation can appear anywhere in a data flow when you normalize a relational source.
20 Informatica simple How to use a sequence created in Oracle in Informatica? By using Stored procedure transformation.
21 Informatica simple What are source qualifier transformations? The source qualifier represents the records that the Informatica Server reads when it runs a session.
22 Informatica simple What are cache and their types in Informatica? The Informatica server creates index and data cache for aggregator, Rank, joiner and Lookup transformations in a mapping. The Informatica server stores key values in the index cache and output values in the data cache.
23 Informatica simple What is an incremental aggregation? In 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 calculation each time you run the session.
24 Informatica complex What is Reject loading? "During a session, the Informatica server creates a reject file for each target instance in the mapping. If the writer or the target rejects data, the Informatica server writes the rejected row into reject file.
The reject file and session log contain information that helps you determine the cause of the reject. You can correct reject files and load them to relational targets using the Informatica reject load utility. The reject loader also creates another reject file for the data that the writer or target reject during the reject loading.
"
25 Informatica average WHAT IS SESSION and BATCHES? "SESSION - A Session Is A set of instructions that tells the Informatica Server How And When To Move Data From Sources To Targets. After creating the session, we can use either the server manager or the command line program pmcmd to start or stop the session.
BATCHES - It Provides A Way to Group Sessions For Either Serial Or Parallel Execution By The Informatica Server. There Are Two Types Of Batches :
1. SEQUENTIAL - Run Session One after the Other.
2. CONCURRENT - Run Session At The Same Time.
"
26 Informatica simple Significance of Source Qualifier Transformation "When you add a relational or a flat file source definition to a mapping, you need to connect it to a Source Qualifier transformation. The Source Qualifier represents the records that the Informatica Server reads when it runs a session. · To join data originating from the same DB.
· Filter records in the Source itself.
· To specify an outer join instead of a default inner join.
· To specify sorter ports.
· To select distinct values from the source.
· To create a custom query to issue a special select statement for the Informatica server to read source data. For example, we might use a custom query to perform aggregate calculations or execute a stored procedure.
"
27 Informatica average What are 2 modes of data movement in Informatica Server? "The data movement mode depends on whether Informatica Server should process single byte or multi-byte character data. This mode selection can affect the enforcement of code page relationships and code page validation in the Informatica Client and Server. a) Unicode – IS allows 2 bytes for each character and uses additional byte for each non-ascii character (such as Japanese characters)
b) ASCII – IS holds all data in a single byte
"
28 Informatica simple Why we use lookup transformations? "Lookup Transformations can access data from relational tables that are not sources in mapping. With Lookup transformation, we can accomplish the following tasks:
a) Get a related value - Get the Employee Name from the Employee table based on the Employee ID
b) Perform Calculation
Update slowly changing dimension tables - We can use unconnected lookup transformation to determine whether the records already exist in the target or not.
"
29 Informatica simple What are confirmed dimensions Confirmed dimensions are linked to multiple fact tables
30 DataWarehousing simple What is Data warehousing "A DW is a DB used for query,analysis and reporting . By definition DW is a subject oriented, intergrated, non volatile and time variant
Subject Oriented:- Represents a subject Aread like sales, Mktg
Integrated :- Data Colleted from multiple source systems integrated into a user readable unique format
Ex:- male, female ,0,1, M,F, T, F
Non Volatile :- Dw stores historical data
Time Variant :- Stores data timewise like weekly,monthly,quarterly, yearly
"
31 Informatica simple What is a reusable transf.. What is a mapplet . Explain diff. Bet them "Reusable tranformation:- if u want to create tranfor that perform common tasks such as avg sal in a dept
Mapplet:- Is a reusuable object that represents a set of transformations
"
32 Informatica simple What happens when u use the delete or update or reject or insert statement in your update strategy? Inserts:- treats all records as inserts , while inserting if the record violates primary, foreign key or foreign key in the database it rejects the record
33 Informatica simple Where do u design ur mappings designer
34 Informatica simple Where do u define users and privileges in Informatica Repository manager
35 Informatica simple How do u debug the data in Informatica tool Use debugger in designer
36 Informatica simple when u run the session does debugger loads the data to target ? If you select the option discard target data then it will not load to target
37 Informatica simple Can u use flat file and table (relational) as source together ? yes
38 Informatica simple suppose I need to separate the data for delete and insert to target depending on the codition, which transformation u use ? Router or filter
39 Informatica average What is the difference between lookup Data cache and Index cache. "Index cache:Contains columns used in condition
Data cache: :Contains other output columns than the condition columns.
"
40 Informatica average What is an indicator file and how it can be used. Indicator file is used for Event Based Scheduling when you don’t know when the Source Data is availaible., A shell command ,script or a batch file creates and send this indicator file to the directory local to the Informatica Server.Server waits for the indicator file to appear before running the session.
41 Informatica simple Different Tools in Designer "· Source Analyzer
· Warehouse designer
· Transformation Developer
· Maplet designer
· Mapping designer
"
42 Informatica simple Components of Informatica "· Designer
· Workflow Manager
· Workflow Monitor
"
43 Informatica simple Different Tools in Workflow Manager "· Task Developer
· Worklet designer
· Workflow Designer
"
44 Informatica simple What is overview window ? Why it is used ? It’s a window in which you can see all the transformations that are used for a mapping.
45 Informatica simple · While using Debugger, how will you fined out which transformation is currently running ? The left hand corner of the transformation that has an arrow looks like moving.
46 Informatica simple How do u load the data using Informatica? Using workflow manager
47 Informatica simple What is an Filter Transformation? or what options u have in Filter Transformation? The Filter transformation provides the means for filtering records in a mapping. You pass all the rows from a source transformation through the Filter transformation, then enter a filter condition for the transformation. All ports in a Filter transformation are input/output, and only records that meet the condition pass through the Filter transformation.
48 Informatica simple What happens to the discarded rows in Filter Transformation. Discarded rows do not appear in the session log or reject files
49 Informatica average What are the two programs that communicate with the Informatica Server? "Informatica provides Server Manager and pmcmd programs to communicate with the Informatica Server:
Server Manager. A client application used to create and manage sessions and batches, and to monitor and stop the Informatica Server. You can use information provided through the Server Manager to troubleshoot sessions and improve session performance.
pmcmd. A command-line program that allows you to start and stop sessions and batches, stop the Informatica Server, and verify if the Informatica Server is running.
"
50 Informatica simple What u can do with Designer ? "The Designer client application provides five tools to help you create mappings:
Source Analyzer. Use to import or create source definitions for flat file, Cobol, ERP, and relational sources.
Warehouse Designer. Use to import or create target definitions.
Transformation Developer. Use to create reusable transformations.
Mapplet Designer. Use to create mapplets.
Mapping Designer. Use to create mappings.
"
51 Informatica avrage What are different types of Tracing Levels u hv in Transformations? "Tracing Levels in Transformations :-
Level Description

Terse Indicates when the Informatica Server initializes the session and its components. Summarizes session results, but not at the level of individual records.
Normal Includes initialization information as well as error messages and notification of rejected data.
Verbose initialization Includes all information provided with the Normal setting plus more extensive information about initializing transformations in the session.
Verbose data Includes all information provided with the Verbose initialization setting.

Note: By default, the tracing level for every transformation is Normal.

To add a slight performance boost, you can also set the tracing level to Terse, writing the minimum of detail to the session log
when running a session containing the transformation.
"
52 Informatica simple What is Mapplet and how do u create Mapplet? "A mapplet is a reusable object that represents a set of transformations. It allows you to reuse transformation logic and can contain as many transformations as you need. Create a mapplet when you want to use a standardized set of transformation logic in several mappings. For example, if you have a several fact tables that require a series of dimension keys, you can create a mapplet containing a series of Lookup
transformations to find each dimension key. You can then use the mapplet in each fact table mapping, rather than recreate the
same lookup logic in each mapping.
"
53 Informatica simple If data source is in the form of Excel Spread sheet then how do use? "PowerMart and PowerCenter treat a Microsoft Excel source as a relational database, not a flat file. Like relational sources, the Designer uses ODBC to import a Microsoft Excel source. You do not need database permissions to import Microsoft Excel sources.
To import an Excel source definition, you need to complete the following tasks:
· Install the Microsoft Excel ODBC driver on your system.
· Create a Microsoft Excel ODBC data source for each source file in the ODBC 32-bit Administrator.
· Prepare Microsoft Excel spreadsheets by defining ranges and formatting columns of numeric data.
· Import the source definitions in the Designer.
Once you define ranges and format cells, you can import the ranges in the Designer. Ranges display as source definitions
when you import the source.
"
54 Informatica simple When do u use connected lookup n when do u use unconnected lookup? "A connected Lookup transformation is part of the mapping data flow. With connected lookups, you can have multiple return values. That is, you can pass multiple values from the same row in the lookup table out of the Lookup transformation.
Common uses for connected lookups include:
=> Finding a name based on a number ex. Finding a Dname based on deptno
=> Finding a value based on a range of dates
=> Finding a value based on multiple conditions
Unconnected Lookups : -
An unconnected Lookup transformation exists separate from the data flow in the mapping. You write an expression using
the :LKP reference qualifier to call the lookup within another transformation.
Some common uses for unconnected lookups include:
=> Testing the results of a lookup in an expression
=> Filtering records based on the lookup results
=> Marking records for update based on the result of a lookup (for example, updating slowly changing dimension tables)
=> Calling the same lookup multiple times in one mapping
"
55 Informatica simple How many values it (informatica server) returns when it passes thru Connected Lookup n Unconncted Lookup? Connected Lookup can return multiple values where as Unconnected Lookup will return only one values that is Return Value.
56 Informatica simple What kind of modifications u can do/perform with each Transformation? "Using transformations, you can modify data in the following ways:
----------------- ------------------------
Task Transformation
----------------- ------------------------
Calculate a value Expression
Perform an aggregate calculations Aggregator
Modify text Expression
Filter records Filter, Source Qualifier
Order records queried by the Informatica Server Source Qualifier
Call a stored procedure Stored Procedure
Call a procedure in a shared library or in the External Procedure
COM layer of Windows NT
Generate primary keys Sequence Generator
Limit records to a top or bottom range Rank
Normalize records, including those read Normalizer
from COBOL sources
Look up values Lookup
Determine whether to insert, delete, update, Update Strategy
or reject records
Join records from different databases Joiner
or flat file systems
"
57 Informatica simple Expressions in Transformations, Explain briefly how do u use? "Expressions in Transformations
To transform data passing through a transformation, you can write an expression. The most obvious examples of these are the
Expression and Aggregator transformations, which perform calculations on either single values or an entire range of values
within a port. Transformations that use expressions include the following:
--------------------- ------------------------------------------
Transformation How It Uses Expressions
--------------------- ------------------------------------------
Expression Calculates the result of an expression for each row passing through the transformation, using values from one or more ports.
Aggregator Calculates the result of an aggregate expression, such as a sum or average, based on all data passing through a port or on groups within that data.
Filter Filters records based on a condition you enter using an expression.
Rank Filters the top or bottom range of records, based on a condition you enter using an expression.
Update Strategy Assigns a numeric code to each record based on an expression, indicating whether the Informatica Server should use the information in the record to insert, delete, or update the target.

In each transformation, you use the Expression Editor to enter the expression. The Expression Editor supports the transformation language for building expressions. The transformation language uses SQL-like functions, operators, and other components to build the expression. For example, as in SQL, the transformation language includes the functions COUNT and SUM. However, the PowerMart/PowerCenter transformation language includes additional functions not found in SQL.

When you enter the expression, you can use values available through ports. For example, if the transformation has two input ports representing a price and sales tax rate, you can calculate the final sales tax using these two values. The ports used in the expression can appear in the same transformation, or you can use output ports in other transformations.

"
58 Informatica average In case of Flat files (which comes thru FTP as source) has not arrived then what happens U get a fatal error which cause server to fail/stop the session.
59 Informatica average What does a load manager do ? "The Load Manager is the primary PowerCenter Server process. It accepts requests from the PowerCenter Client and from pmcmd. The Load Manager runs and monitors the workflow. It performs the following tasks: Starts the session, creates DTM process and sends pre & post session emails.
1.Manages the session and batch scheduling
2.locks the session and reads the session properties.
3. expands the session and server variables and parameters
4. validates the source and target code pages
5. verifies the permissions and privileges
6. creates session log file
7. creates DTM process which executes the session

"
60 Informatica simple What is a cache Temporary memory area used to store intermediate results
61 Informatica simple What is an Expression transformation? "Expression transformation is used to calculate expressions on a row by row basis. Total_sal = Com * sal

"
62 Informatica simple I have two sources S1 having 100 records and S2 having 10000 records, I want to join them, using joiner transformation. Which of these two sources (S1,S2) should be master to improve my performance? Why? S1 should be the master as it contains few records so that the usage of cache can be reduced , S2 should be detail.
63 Informatica average I have a source and I want to generate sequence numbers using mappings in informatica. But I don’t want to use sequence generator transformation. Is there any other way to do it? YES, Write a stored procedure and use Stored Procedure Transformation
64 Informatica average What is a bad file? Bad file is the file which contains the data rejected by the writer or target.
65 Informatica average What is the first column of the bad file? "Record / Row indicator
0,1,2,3
0 – insert -- Rejected by writer/target
1- update -- Rejected by writer/target
2- delete -- Rejected by writer/target
3-reject -- Rejected by writer --- coz update st. has marked it for reject.

"
66 Informatica average What are the contents of the cache directory in the server Index cache files and Data caches
67 Informatica simple Is lookup a Active transformation or Passive transformation ? Passive.
68 Informatica simple What is a Mapping? Mapping Represent the data flow between source and target
69 Informatica simple What are the types of transformations Passive and active
70 Informatica simple If a sequence generator (with increment of 1) is connected to (say) 3 targets and each target uses the NEXTVAL port, what value will each target get? Each target will get the value in multiple of 3
71 Informatica average Have you used the Abort, Decode functions? "Abort can be used to Abort / stop the session on an error condition.
If the primary key column contains NULL, and you need to stop the session from continuing then you may use ABORT function in the default value for the port. It can be used with IIF and DECODE function to Abort the session.
"
72 Informatica average What do you know about the Informatica server architecture? Load Manager, DTM, Reader, Writer, Transformer "o Load Manager is the first process started when the session runs. It checks for validity of mappings, locks sessions and other objects.
o DTM process is started once the Load Manager has completed its job. It starts a thread for each pipeline.
o Reader scans data from the specified sources.
o Writer manages the target/output data.
o Transformer performs the task specified in the mapping.

"
73 Informatica simple What are the default values for variables? String = Null, Number = 0, Date = 1/1/1753
74 Informatica simple How many ways you can filter the records? "1. Source Qualifier
2. Filter transformation
3. Router transformation
4. Ranker
5. Update strategy
"
75 Informatica complex · How do you identify the bottlenecks in Mappings? "Bottlenecks can occur in
1. Targets
The most common performance bottleneck occurs when the informatica server writes to a target database. You can identify target bottleneck by configuring the session to write to a flat file target.
If the session performance increases significantly when you write to a flat file, you have a target bottleneck.
Solution :
Drop or Disable index or constraints
Perform bulk load (Ignores Database log)
Increase commit interval (Recovery is compromised)
Tune the database for RBS, Dynamic Extension etc.,

2. Sources
Set a filter transformation after each SQ and see the records are not through.
If the time taken is same then there is a problem.
You can also identify the Source problem by
Read Test Session – where we copy the mapping with sources, SQ and remove all transformations and connect to file target. If the performance is same then there is a Source bottleneck.
Using database query – Copy the read query directly from the log. Execute the query against the source database with a query tool. If the time it takes to execute the query and the time to fetch the first row are significantly different, then the query can be modified using optimizer hints.
Solutions:
Optimize Queries using hints.
Use indexes wherever possible.

3. Mapping
If both Source and target are OK then problem could be in mapping.
Add a filter transformation before target and if the time is the same then there is a problem.
(OR) Look for the performance monitor in the Sessions property sheet and view the counters.
Solutions:
If High error rows and rows in lookup cache indicate a mapping bottleneck.
Optimize Single Pass Reading:
Optimize Lookup transformation :
1. Caching the lookup table:
When caching is enabled the informatica server caches the lookup table and queries the cache during the session. When this option is not enabled the server queries the lookup table on a row-by row basis.
Static, Dynamic, Shared, Un-shared and Persistent cache
2. Optimizing the lookup condition
Whenever multiple conditions are placed, the condition with equality sign should take precedence.
3. Indexing the lookup table
The cached lookup table should be indexed on order by columns. The session log contains the ORDER BY statement
The un-cached lookup since the server issues a SELECT statement for each row passing into lookup transformation, it is better to index the lookup table on the columns in the condition

Optimize Filter transformation:
You can improve the efficiency by filtering early in the data flow. Instead of using a filter transformation halfway through the mapping to remove a sizable amount of data.
Use a source qualifier filter to remove those same rows at the source,
If not possible to move the filter into SQ, move the filter transformation as close to the source qualifier as possible to remove unnecessary data early in the data flow.
Optimize Aggregate transformation:
1. Group by simpler columns. Preferably numeric columns.
2. Use Sorted input. The sorted input decreases the use of aggregate caches. The server assumes all input data are sorted and as it reads it performs aggregate calculations.
3. Use incremental aggregation in session property sheet.
Optimize Seq. Generator transformation:
1. Try creating a reusable Seq. Generator transformation and use it in multiple mappings
2. The number of cached value property determines the number of values the informatica server caches at one time.
Optimize Expression transformation:
1. Factoring out common logic
2. Minimize aggregate function calls.
3. Replace common sub-expressions with local variables.
4. Use operators instead of functions.

4. Sessions
If you do not have a source, target, or mapping bottleneck, you may have a session bottleneck.
You can identify a session bottleneck by using the performance details. The informatica server creates performance details when you enable Collect Performance Data on the General Tab of the session properties.
Performance details display information about each Source Qualifier, target definitions, and individual transformation. All transformations have some basic counters that indicate the Number of input rows, output rows, and error rows.
Any value other than zero in the readfromdisk and writetodisk counters for Aggregate, Joiner, or Rank transformations indicate a session bottleneck.
Low bufferInput_efficiency and BufferOutput_efficiency counter also indicate a session bottleneck.
Small cache size, low buffer memory, and small commit intervals can cause session bottlenecks.
5. System (Networks)
"
76 Informatica complex How to improve the Session performance? "1 Run concurrent sessions
2 Partition session (Power center)
3. Tune Parameter – DTM buffer pool, Buffer block size, Index cache size, data cache size, Commit Interval, Tracing level (Normal, Terse, Verbose Init, Verbose Data)
The session has memory to hold 83 sources and targets. If it is more, then DTM can be increased.
The informatica server uses the index and data caches for Aggregate, Rank, Lookup and Joiner transformation. The server stores the transformed data from the above transformation in the data cache before returning it to the data flow. It stores group information for those transformations in index cache.
If the allocated data or index cache is not large enough to store the date, the server stores the data in a temporary disk file as it processes the session data. Each time the server pages to the disk the performance slows. This can be seen from the counters .
Since generally data cache is larger than the index cache, it has to be more than the index.
4. Remove Staging area
5. Tune off Session recovery
6. Reduce error tracing
"
77 Informatica What is Business components ? Where it exists ? "It is available in navigator inside the folder.

"
78 Informatica complex What are Short cuts ? Where it is used ? "Shortcuts allow you to use metadata across folders without making copies, ensuring uniform metadata. A shortcut inherits all properties of the object to which it points. Once you create a shortcut, you can configure the shortcut name and description.
When the object the shortcut references changes, the shortcut inherits those changes. By using a shortcut instead of a copy, you ensure each use of the shortcut matches the original object. For example, if you have a shortcut to a target definition, and you add a column to the definition, the shortcut inherits the additional column.
· Scenario1
Here is a table with Single Row, in a target table the same row should be populated 10 times.
Using Normalizer, we can do it. Hint : Normalizer / Occurs make it 10 and
Have 10 inputs and a output. You will get 10 rows.
"
79 Informatica simple While importing the relational source definition from database, what are the meta data of source U import? "Source name
Database location
Column names
Data types
Key constraints
"
80 Informatica simple . How many ways U can update a relational source definition and what r they? "Two ways
1. Edit the definition
2. Re-import the definition

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81 Informatica simple How many ways u create ports? "Two ways
1. Drag the port from another transformation
2. Click the add button on the ports tab.

"
82 Informatica average .What r the unsupported repository objects for a mapplet? " COBOL source definition
Joiner transformations
Normalizer transformations
Non reusable sequence generator transformations.
Pre or post session stored procedures
Target definitions
Power mart 3.5 style Look Up functions
XML source definitions
IBM MQ source definitions
"
83 Informatica simple What r the mapping parameters and mapping variables? "Mapping parameter represents a constant value that U can define before running a session. A mapping parameter retains the same value throughout the entire session.
When u use the mapping parameter ,U declare and use the parameter in a mapping or maplet. Then define the value of parameter in a parameter file for the session.
Unlike a mapping parameter, a mapping variable represents a value that can change throughout the session. The informatica server saves the value of mapping variable to the repository at the end of session run and uses that value next time U run the session.

"
84 Informatica simple Can U use the mapping parameters or variables created in one mapping into another mapping? "NO.
We can use mapping parameters or variables in any transformation of the same mapping or mapplet in which U have created mapping parameters or variables.

"
85 Informatica simple Can u use the mapping parameters or variables created in one mapping into any other reusable transformation? Yes. Because reusable transformation is not contained with any maplet or mapping.
86 Informatica simple How can U improve session performance in aggregator transformation? Use sorted input.
87 Informatica simple .What r the difference between joiner transformation and source qualifier transformation? " U can join heterogeneous 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 data source in sourcequalifier. U can join relational sources which r coming from different sources also.

"
88 Informatica simple In which conditions we can not use joiner transformation(Limitations 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.
"
89 Informatica simple What r the settings that u use to configure the joiner transformation? "Master and detail source
Type of join
Condition of the join

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90 Informatica simple What r the join types in joiner transformation? "Normal (Default)
Master outer
Detail outer
Full outer
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91 Informatica simple How the informatica server sorts the string values in Rank transformation? "When the informatica server runs in the ASCII data movement mode it sorts session data using Binary sort order. If U configure the session to use a binary sort order, the informatica server calculates the binary value of each string and returns the specified number of rows with the highest binary values for the string.

"
92 Informatica simple What is the Rank index in Rank transformation? "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:

"
93 Informatica simple What is the Router transformation? "Input group
Output group
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
"
94 Informatica simple What r the types of groups in Router transformation? " 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.
"
95 Informatica simple Why we use stored procedure transformation? " For populating and maintaining data bases.

"
96 average What r the types of data that passes between informatica server and stored procedure? "3 types of data
Input/Out put parameters
Return Values
Status code.

"
97 Informatica average What is the status code? "Status code provides error handling for the informatica server during the session. The stored procedure issues a status code that notifies whether or not stored procedure completed sucessfully. This value can not seen by the user. It only used by the informatica server to determine whether to continue running the session or stop.

"
98 Informatica simple What r the tasks that source qualifier performs? "Join data originating from same source data base.
Filter records when the informatica server reads source data.
Specify an outer join rather than the default inner join
specify sorted records.
Select only distinct values from the source.
Creating custom query to issue a special SELECT statement for the informatica server to read
source data.
"
99 Informatica simple What is the default join that source qualifier provides? Inner equi join.
100 Informatica simple . What r the basic needs to join two sources in a source qualifier? "Two sources should have primary and Foreign key relation ships.
Two sources should have matching data types.

"
101 Informatica simple what is update strategy transformation ? " This transformation is used to maintain the history data or just most recent changes in to target
table.
"
102 Informatica simple Describe two levels in which update strategy transformation sets? Within a session. When you configure a session, you can instruct the Informatica Server to either treat all records in the same way (for example, treat all records as inserts), or use instructions coded into the session mapping to flag records for different database operations. Within a mapping. Within a mapping, you use the Update Strategy transformation to flag records for insert, delete, update, or reject.
103 Informatica average What is the default source option for update strategy transformation? Data driven.
104 Informatica average What is Data driven? " The informatica server follows instructions coded into update strategy transformations with in the session mapping determine how to flag records for insert, update, delete or reject.
If u do not choose data driven option setting, the informatica server ignores all update strategy transformations in the mapping.

"
105 Informatica simple "What r the options in the target session of update strategy transformation?

" " Insert
Delete
Update
Update as update
Update as insert
Update else insert
Truncate table
"
106 Informatica simple What r the types of mapping wizards that r to be provided in Informatica? "The Designer provides two mapping wizards to help you create mappings quickly and easily. Both wizards are designed to create mappings for loading and maintaining star schemas, a series of dimensions related to a central fact table. Getting Started Wizard. Creates mappings to load static fact and dimension tables, as well as slowly growing dimension tables.
Slowly Changing Dimensions Wizard. Creates mappings to load slowly changing dimension tables based on the amount of historical dimension data you want to keep and the method you choose to handle historical dimension data.

"
107 Informatica simple What r the types of mapping in Getting Started Wizard? "Simple Pass through mapping :

Loads a static fact or dimension table by inserting all rows. Use this mapping when you want to drop all existing data from your table before loading new data.

Slowly Growing target :

Loads a slowly growing fact or dimension table by inserting new rows. Use this mapping to load new data when existing data does not require updates.

"
108 Informatica avrage What r the mappings that we use for slowly changing dimension table? "Type1: Rows containing changes to existing dimensions are updated in the target by overwriting the existing dimension. In the Type 1 Dimension mapping, all rows contain current dimension data.
Use the Type 1 Dimension mapping to update a slowly changing dimension table when you do not need to keep any previous versions of dimensions in the table.

Type 2: The Type 2 Dimension Data mapping inserts both new and changed dimensions into the target. Changes are tracked in the target table by versioning the primary key and creating a version number for each dimension in the table.
Use the Type 2 Dimension/Version Data mapping to update a slowly changing dimension table when you want to keep a full history of dimension data in the table. Version numbers and versioned primary keys track the order of changes to each dimension.

Type 3: The Type 3 Dimension mapping filters source rows based on user-defined comparisons and inserts only those found to be new dimensions to the target. Rows containing changes to existing dimensions are updated in the target. When updating an existing dimension, the Informatica Server saves existing data in different columns of the same row and replaces the existing data with the updates

"
109 Informatica average What r the different types of Type2 dimension mapping? "Type2 Dimension/Version Data Mapping: In this mapping the updated dimension in the source will gets inserted in target along with a new version number. And newly added dimension
in source will insert into target with a primary key.

Type2 Dimension/Flag current Mapping: This mapping is also used for slowly changing dimensions. In addition it creates a flag value for changed or new dimension.
Flag indicates the dimension is new or newly updated. Recent dimensions will gets saved with current flag value 1. And updated dimensions r saved with the value 0.

Type2 Dimension/Effective Date Range Mapping: This is also one flavor of Type2 mapping used for slowly changing dimensions. This mapping also inserts both new and changed dimensions in to the target. And changes r tracked by the effective date range for each version of each dimension.

"
110 Informatica average How can u recognize whether or not the newly added rows in the source r gets insert in the target ? "In the Type2 mapping we have three options to recognize the newly added rows
Version number
Flag value
Effective date Range

"
111 Informatica average What r two types of processes that informatica runs the session? "Load manager Process: Starts the session, creates the DTM process, and sends post-session email when the session completes.
The DTM process. Creates threads to initialize the session, read, write, and transform data, and handle pre- and post-session operations.
"
112 Informatica What r the features of the server manager in the informatica 5.0? " U can use command line arguments for a session or batch. This allows U to change the values of session parameters, and mapping parameters and mapping variables.

Parallel data processing: This feature is available for power center only. If we use the informatica server on a SMP system, U can use multiple CPU's to process a session concurrently.

Process session data using threads: Informatica server runs the session in two processes. Explained in previous question.

"
113 Informatica simple Can u generate reports in Informatica? "Yes. By using Metadata reporter we can generate reports in informatica.

"
114 Informatica simple What is metadata reporter? "It is a web based application that enables you to run reports against repository metadata.
With a meta data reporter, u can access information about Ur repository with out having knowledge of sql, transformation language or underlying tables in the repository.

"
115 Informatica simple Define mapping and sessions? "Mapping: It is a set of source and target definitions linked by transformation objects that define the rules for transformation.
Session : It is a set of instructions that describe how and when to move data from source to targets.
"
116 Informatica simple Which tool U use to create and manage sessions and batches and to monitor and stop the informatica server? Informatica server manager.
117 Informatica simple Why we use partitioning the session in informatica? " Partitioning achieves the session performance by reducing the time period of reading the source and loading the data into target.

"
118 Informatica simple To achieve the session partition what r the necessary tasks u have to do? "Configure the session to partition source data.

Install the informatica server on a machine with multiple CPU's.

"
119 Informatica avrage How the informatica server increases the session performance through partitioning the source? " For relational sources informatica server creates multiple connections for each partition of a single source and extracts separate range of data for each connection. Informatica server reads multiple partitions of a single source concurently. Similarly for loading also informatica server creates multiple connections to the target and loads partitions of data concurrently.

For XML and file sources, informatica server reads multiple files concurrently. For loading the data informatica server creates a separate file for each partition(of a source file).U can choose to merge the targets.

"
120 Informatica simple . Why u use repository connectivity? " When u edit, schedule the session each time, informatica server directly communicates the repository to check whether or not the session and users r valid. All the metadata of sessions and mappings will be stored in repository.

"
121 Informatica average What r the tasks that Load manger process will do? "Manages the session and batch scheduling: When u start the informatica server the load manager launches and queries the repository for a list of sessions configured to run on the informatica server. When u configure the session the load manager maintains list of list of sessions and session start times. When u start a session load manger fetches the session information from the repository to perform the validations and verifications prior to starting DTM processLocking and reading the session: When the informatica server starts a session load manager locks the session from the repository. Locking prevents U starting the session again and again.

Reading the parameter file: If the session uses a parameter files, load manager reads the parameter file and verifies that the session level parameters are declared in the file

Verifies permission and privileges: When the session starts load manger checks whether or not the user have privileges to run the session.

"
122 Informatica average What is DTM process? "After the load manger performs validations for session, it creates the DTM process. DTM is to create and manage the threads that carry out the session tasks. I creates the master thread. Master thread creates and manages all the other threads.

"
123 Informatica average What r the different threads in DTM process? "Master thread: Creates and manages all other threads

Mapping thread: One mapping thread will be creates for each session. Fetches session and mapping information.

Pre and post session threads: This will be created to perform pre and post session operations.

Reader thread: One thread will be created for each partition of a source. It reads data from source.

Writer thread: It will be created to load data to the target.

Transformation thread: It will be created to transform data.

"
124 Informatica average What r the data movement modes in informatica? " Data movement modes determines how informatica server handles the character data. U choose the data movement in the informatica server configuration settings. Two types of data movement modes available in informatica.

ASCII mode
Uni code mode.

"
125 Informatica average What r the out put files that the informatica server creates during the session running? "Informatica server log: Informatica server(on UNIX) creates a log for all status and error messages(default name: pm.server.log).It also creates an error log for error messages. These files will be created in informatica home directory.

Session log file: Informatica server creates session log file for each session. It writes information about session into log files such as initialization process, creation of sql commands for reader and writer threads, errors encountered and load summary. The amount of detail in session log file depends on the tracing level that u set.

Session detail file: This file contains load statistics for each target in mapping. Session detail include information such as table name, number of rows written or rejected. U can view this file by double clicking on the session in monitor window

Performance detail file: This file contains information known as session performance details which helps U where performance can be improved. To generate this file select the performance detail option in the session property sheet.

Reject file: This file contains the rows of data that the writer does not write to targets.

Control file: Informatica server creates control file and a target file when U run a session that uses the external loader. The control file contains the information about the target flat file such as data format and loading instructions for the external loader.

Post session email: Post session email allows U to automatically communicate information about a session run to designated recipients. U can create two different messages. One if the session completed successfully the other if the session fails.

Indicator file: If u use the flat file as a target, U can configure the informatica server to create indicator file. For each target row, the indicator file contains a number to indicate whether the row was marked for insert, update, delete or reject.

output file: If session writes to a target file, the informatica server creates the target file based on file properties entered in the session property sheet.

Cache files: When the informatica server creates memory cache it also creates cache files. For the following circumstances informatica server creates index and data cache files.

Aggregator transformation
Joiner transformation
Rank transformation
Lookup transformation

"
126 Informatica complex In which circumstances that informatica server creates Reject files? "When it encounters the DD_Reject in update strategy transformation.
Violates database constraint
Filed in the rows was truncated or overflowed.
"
127 Informatica average What is polling? " It displays the updated information about the session in the monitor window. The monitor window displays the status of each session when U poll the informatica server

"
128 Informatica average Can u copy the session to a different folder or repository? Yes. By using copy session wizard u can copy a session in a different folder or repository. But that target folder or repository should consists of mapping of that session. If target folder or repository is not having the mapping of copying session , u should have to copy that mapping first before u copy the session.
129 Informatica average . What is batch and describe about types of batches? "Grouping of session is known as batch. Batches r two types

Sequential: Runs sessions one after the other

Concurrent: Runs session at same time.

If u have sessions with source-target dependencies u have to go for sequential batch to start the sessions one after another. If u have several independent sessions u can use concurrent batches. Which runs all the sessions at the same time.

"
130 Informatica average Can u copy the batches? NO
131 Informatica average .How many number of sessions that u can create in a batch? "Any number of sessions.

"
132 Informatica simple 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.
133 Informatica simple . What is a command that used to run a batch pmcmd is used to start a batch.
134 Informatica simple What r the different options used to configure the sequential batches? "Two optionsRun the session only if previous session completes successfully.
Always runs the session.


"
135 Informatica simple In a sequential batch can u run the session if previous session fails? "Yes. By setting the option always runs the session.

"
136 Informatica average Can u start 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.
137 Informatica average Can u start a session inside a batch individually? "We can start our required session only in case of sequential batch. in case of concurrent batch
we can’t do like this.
"
138 Informatica average How can u stop a batch? "By using server manager or pmcmd.

"
139 Informatica simple What r the session parameters? "Session parameters r like mapping parameters, represent values U might want to change between
sessions such as database connections or source files.
Server manager also allows U to create user defined 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.

"
140 Informatica simple 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
Mapping parameters
Mapping variables
session parameters

"
141 Informatica simple How can u access the remote source into Ur session? "Relational source: To access relational source which is situated in a remote place ,u need to
configure database connection to the data source.

File Source : To access the remote source file U must configure the FTP connection to the
host machine before u create the session.

Heterogeneous : When Ur mapping contains more than one source type, the server manager creates
a heterogeneous session that displays source options for all types.

"
142 Informatica average What is difference between portioning of relational target and partitioning of file targets? "If u partition a session with a relational target informatica server creates multiple connections
to the target database to write target data concurrently. 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.
"
143 Informatica average what r the transformations that restricts the partitioning of sessions? " Advanced External procedure transformation 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 partition the associated source

Joiner Transformation : U can not partition the master source for a joiner transformation

Normalizer Transformation

XML targets.
"
144 Informatica complex ". 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 often affect on session performance. So avoid network connections.

Flat files: If ur flat files stored on a machine other than the informatica server, move those files to the machine that consists of informatica server.
Relational data sources: 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 data passes.
Removing of staging areas may improve session performance.

U can run the multiple informatica servers against the same repository. Distributing the session load to multiple informatica servers may improve session performance.

Run the informatica server in ASCII data movement mode improves the session performance. Because ASCII data movement 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 concurrent batches may also increase the session performance.

Partitioning the session improves the session performance by creating multiple connections to sources and targets and loads data in parallel pipe lines.

In some cases if a session contains an aggregator transformation ,u can use incremental aggregation to improve session performance.

Avoid transformation errors to improve the session performance.

If the session contained lookup transformation u can improve the session performance by enabling the look up cache.

If Ur session contains filter transformation ,create that filter transformation nearer to the sources
or u can use filter condition in source qualifier.

Aggregator, Rank and joiner transformation may often decrease the session performance .Because they must group data before processing it. To improve session performance in this case use sorted ports option.
"
145 Informatica simple 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.These tables
stores metadata in specific format the informatica server, client tools use.

"
146 Informatica simple "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 definitions
Transformations
"
147 Informatica simple 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.
148 Informatica average How can u work with remote database in informatica? did u work directly by using remote "To work with remote data source 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 fewer amounts of data across the network in a particular time.

"
149 Informatica average what is incremental 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.
150 Informatica simple ". What r the scheduling options to run a session?

" "U can schedule a session to run at a given time or interval, or u can manually run the session.

Different options of scheduling

Run only on demand: Informatica 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 intervals as u configured.
Customized repeat: Informatica server runs the session at the dates and times specified in the repeat dialog box.

"
151 Informatica simple What is tracing level and what r the types of tracing level? "Tracing level represents the amount of information that informatica server writes in a log file.
Types of tracing level

Normal
Verbose
Verbose init
Verbose data
"
152 Informatica simple What is difference between stored procedure transformation and external procedure transformation? In case of stored procedure transformation procedure will be compiled and executed in a relational data source. U need data base connection to import the stored procedure in to ur maping. Where as in external procedure transformation procedure or function will be executed out side of data source. ie u need to make it as a DLL to access in u r mapping. No need to have data base connection in case of external procedure transformation.
153 Informatica complex Explain about Recovering sessions? " If you stop a session or if an error causes a session to stop, refer to the session and error logs to determine the cause of failure. Correct the errors, and then complete the session. The method you use to complete the session depends on the properties of the mapping, session, and Informatica Server configuration.
Use one of the following methods to complete the session:
· Run the session again if the Informatica Server has not issued a commit.
· Truncate the target tables and run the session again if the session is not recoverable.
· Consider performing recovery if the Informatica Server has issued at least one commit.
"
154 Informatica complex If a session fails after loading of 10,000 records in to the target. How can u load the records from 10001st record when u run the session next time? "As explained above informatica server has 3 methods to recovering the sessions. Use performing recovery to load the records from where the session fails.

"
155 Informatica complex Explain about perform recovery? "When the Informatica Server starts a recovery session, it reads the OPB_SRVR_RECOVERY table and notes the row ID of the last row committed to the target database. The Informatica Server then reads all sources again and starts processing from the next row ID. For example, if the Informatica Server commits 10,000 rows before the session fails, when you run recovery, the Informatica Server bypasses the rows up to 10,000 and starts loading with row 10,001.
By default, Perform Recovery is disabled in the Informatica Server setup. You must enable Recovery in the Informatica Server setup before you run a session so the Informatica Server can create and/or write entries in the OPB_SRVR_RECOVERY table.
"
156 Informatica complex How to recover the standalone session? "A standalone session is a session that is not nested in a batch. If a standalone session fails, you can run recovery using a menu command or pmcmd. These options are not available for batched sessions.

To recover sessions using the menu:
1. In the Server Manager, highlight the session you want to recover.
2. Select Server Requests-Stop from the menu.
3. With the failed session highlighted, select Server Requests-Start Session in Recovery Mode from the menu.

To recover sessions using pmcmd:
1.From the command line, stop the session.
2. From the command line, start recovery.
"
157 Informatica complex How can u recover the session in sequential batches? " If you configure a session in a sequential batch to stop on failure, you can run recovery starting with the failed session. The Informatica Server completes the session and then runs the rest of the batch. Use the Perform Recovery session property

To recover sessions in sequential batches configured to stop on failure:

1.In the Server Manager, open the session property sheet.
2.On the Log Files tab, select Perform Recovery, and click OK.
3.Run the session.
4.After the batch completes, open the session property sheet.
5.Clear Perform Recovery, and click OK.

If you do not clear Perform Recovery, the next time you run the session, the Informatica Server attempts to recover the previous session.
If you do not configure a session in a sequential batch to stop on failure, and the remaining sessions in the batch complete, recover the failed session as a standalone session.

"
158 Informatica complex How to recover sessions in concurrent batches? "If multiple sessions in a concurrent batch fail, you might want to truncate all targets and run the batch again. However, if a session in a concurrent batch fails and the rest of the sessions complete successfully, you can recover the session as a standalone session.
To recover a session in a concurrent batch:
1.Copy the failed session using Operations-Copy Session.
2.Drag the copied session outside the batch to be a standalone session.
3.Follow the steps to recover a standalone session.
4.Delete the standalone copy.

"
159 Informatica complex How can u complete unrecoverable sessions? Under certain circumstances, when a session does not complete, you need to truncate the target tables and run the session from the beginning. Run the session from the beginning when the Informatica Server cannot run recovery or when running recovery might result in inconsistent data.
160 Informatica complex What r the circumstances that informatica server results an unrecoverable session? "The source qualifier transformation does not use sorted ports.
If u change the partition information after the initial session fails.
Perform recovery is disabled in the informatica server configuration.
If the sources or targets changes after initial session fails.
If the mapping consists of sequence generator or normalizer transformation.
If a concurrent batch contains multiple failed sessions.
"
161 Informatica average If i've done any modifications for my table in back end does it reflect in informatica warehouse or mapping designer or source analyzer? "NO. Informatica is not at all concern with back end data base. It displays u all the information
that is to be stored in repository. If want to reflect back end changes to informatica screens,
again u have to import from back end to informatica by valid connection. And u have to replace the existing files with imported files.

"
162 Informatica average After dragging the ports of three sources(sql server,oracle,informix) to a single source qualifier, can u map these three ports directly to target? NO. Unless and until u join those three ports in source qualifier u cannot map them directly.
163 Informatica Server Variables "1. $PMRootDir
2. $PMSessionLogDir
3. $PMBadFileDir
4. $PMCacheDir
5. $PMTargetFileDir
6. $PMSourceFileDir
7. $PMExtProcDir
8. $PMTempDir
9. $PMSuccessEmailUser
10. $PMFailureEmailUser
11. $PMSessionLogCount
12. $PMSessionErrorThreshold
13. $PMWorkflowLogDir
14. $PMWorkflowLogCount
15. $PMLookupFileDir"
164 Informatica Folders "Folders provide a way to organize and store all metadata in the repository, including mappings, schemas, and sessions. Folders are designed to be flexible, to help you logically organize the repository. Each folder has a set of configurable properties that help you define how users access the folder. For example, you can create a folder that allows all repository users to see objects within the folder, but not to edit them. Or, you can create a folder that allows users to share objects within the folder. You can create shared and non-shared folders.

Note: You must create a folder in a repository before you can connect to the repository using the Designer or Workflow Manager.
You create and maintain folders in the Repository Manager. In the Repository Manager, you can view the users accessing folders and the objects within each folder. You can also copy and replace folders within the repository or across repositories.
"
165 Informatica Multiple Servers Register multiple PowerCenter Servers. When you register multiple PowerCenter Servers, choose the PowerCenter Server for a workflow in the workflow properties.

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