Tuesday 24 May 2011

Informatica Real time Scenarios.

Scenario 1: How can we load first and last record from a flat file source to target?

Solution:

Create two pipelines in a mapping

1st pipeline would capture the first record, and 2nd one for last record.

1st Pipeline:

src-> sq-> exp(take a variable port with numeric data type and pass through a output port 'O_Test')->filter(pass if only

O_Test =1)->tgt

2nd pipeline:

src->sq->agg(No group it will pass only last entry)->tgt

In session for 2nd instance of target enable 'Append if Exists' option

Scenario 2: How to find out nth row in flat file...we used to do top N analysis by using  rownum & some other functionalities  by using rowid when source is table .and my query is how to achieve the same functionalities when my source is flat file?

Solution: In the Mapping designer, go to Mappings-> Parameters and Variables.

Here we have two things - Parameters(constant values passed to the mapping) and variables which are dynamic and can be stored as a metadata for future runs(for example you want to do an incremental load into a table B from table A. So you can define a variable which holds the seqid from source. Before you write the data into target , create an expression and source the seqid from source as input and create a variable Max_seqid as output. Now update this value for each row. when the session finishes informatica saves the last read seqid and you can use this in your source qualifier when you run the mapping next time. Please see Infa doc for setmaxvaribale and setminvariables.

In this case, we have to just make use parameters to find the nth row.

Create a parameter(type) - Last_row_number and select datatype as integer or double.

Now you have to create a parameter file on unix box before you call the workflow.

something like this

echo '[<FOLDERNAME>.WF:<WorkflowName>.ST:<SessionName>]'

count=`wc -l filename`

echo "\$\$MappingVariable="$count

Name the parameter file as <workflowname>.par and copy the complete path of the file name and update the "Parameter filename" field under Properties tab in workflow edit tasks.

You can then use this variable in your mapping wherever you want. Just proceed it with two $$.

Scenario 3: How to create flat file dynamically?

SRC FILE             TRGT 1                                  Trgt 2

---------------- --------------------------------     --------------------------------------

Eid Name Sal      Eid Name Sal                          Eid Name Sal

10 a 100             10 a 100                                 20 b 100

20 b 100             10 c 200                                 20 d 300

10 c 200

20 d 300

Solution :

1. Sort the data coming from the source based on EID.

2. Create a variable in an expression transformation that would track the change in EID e.g. in your case if the data is sorted based on EID then it would look like

EID     Name      SAL     

10     a               100

10     c               200

20     b               100

20     d               300

Whenever there is a change in EID the variable would track it

variable1= IIF(EID = PREV_EID, 0, 1)

3. Add a transaction control transformation in the map with a similar condition

IIF(variable1 = 1, TC_COMMIT_BEFORE, TC_CONTINUE_TRANSACTION)

this would create a new file whenever there is a change in the EID value.

4. Add a "filename" port in the target and then pass on a value as per your requirement so that the filenames get generated dynamically as per your requirement.

Scenario 4: I HAVE A SOURCE FILE CONTAINING

1|A,1|B,1|C,1|D,2|A,2|B,3|A,3|B

AND IN TARGET I SHOULD GET LIKE

1|A+B+C+D

2|A+B

3|A+B

Solution:

Follow the logic given below in the expression and you will get your output.

Please ensure that all the ports you mentioned below are variable ports and the incoming data should be sorted by key,data

 

VarPorts

Assigned

Row1

Row2

Row3

Row4

V_CURNT

KEY

1

1

1

2

V_CURNT_DATA

DATA

a

b

c

d

v_OUT

(variable port)

IIF(isnull(v_PREV_DATA) or length(v_PREV_DATA)=5,v_CURNT_DATA,iif(V_CURNT = V_PREV, V_PREV_DATA||'~'||V_CURNT_DATA,NULL)

a

a~b

a~b~c

d

o_OUT

v_OUT

a

a~b

a~b~c

d

V_PREV

V_CURNT

null

1

1

1

V_PREV_DATA

v_OUT

null

a

a~b

a~b~c

And After the expression transformation, you have to add an aggregator tx with group by port as 'key'. this will return the last record with the key.

Hi all the above scenario’s have been taken from informatica communities.Incase any one needs any info about the scenarios discussed then they may contact for clarifications.

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