Informatica Project Explonation

Project Explanation:

 I’m giving generic explanation of the project. Any project either banking or sales or insurance can use this explanation.

 First u have to start with

1) U have to first explain about objective of the project and what is client expectations

2)  U have to start where ur involvement and responsibility of ur job and limitations of job. Add some points from post Project Architecture reply like offshore and onsite model and team structure..etc., Main objective of this project is we are providing a system with all the information regarding Sales /Transactions (sales if sales domain / transactions if bank domain or insurance domain) of entire organizations all over the country US / UK (based on the client location US/UK/…..). we will get the daily transaction data from all branches at the end of the day. We have to validate the transactions and implement the business logic based on the transactions type or transaction code. We have to load all historical data into dwh and once finished historical data. We have to load Delta Loads. Delta load means last 24 hrs transactions captured from the source system. In other words u can call it as Change Data Capture (CDC). This Delta loads are scheduled daily basis. Pick some points from What is Target Staging Area Post.. Source to Staging mappings, staging to warehousing.. based on ur comfort level..Each transaction contains Transaction code.. based on the transaction code u can identify whether that transaction belongs to sales, purchase / car insurance, health insurance, / deposit , loan, payment ( u have to change the words based on the project..) etc., based on that code business logic will be change.. we validate and calculate the measure and load to database.

 One Mapping explanation: In Informatica mapping, we first lookup all the transaction codes with code master table to identify the transaction type to implement the correct logic and filter the unnecessary transactions.. because in an organization there are lot of transactions will be there but u have to consider only required transactions for ur project.. the transaction code exists in the code master table are only transactions u have to consider and other transactions load into one table called Wrap table and invalid records( transaction code missing, null, spaces) to error table. For each dimension table we are creating surrogate key and load into dwh tables.

SCD2 Mapping: We are implementing SCD2 mapping for customer dimension or account dimension to keep history of the accounts or customers. We are using SCD2 Date method. Before telling this u should know it clearly abt thisSCD2 method...Careful abt it...Responsibilities... pick from Project architecture Post and tell according ur comfortable level.. We are responsible for only development and testing and scheduling we are using third party tools..(Control M, AutoSys, Job Tracker, Tivoli or etc...) We simply give the dependencies between each mapping and runtime. Based on that Information scheduling tool team will schedule the mappings. We won’t schedule in Informatica... that’s it Finished…Please Let me know if u required more explanation regarding any point reply ……

Informatica Interview Questions

What are the differences between Connected and Unconnected Lookup?

Connected lookup participates in dataflow and receives input directly from the pipeline Unconnected lookup receives input values from the result of a LKP: expression in another transformation

Connected lookup can use both dynamic and static cache

Unconnected Lookup cache can NOT be dynamic Connected lookup can return more than one column value ( output port )

Unconnected Lookup can return only one column value i.e. output port

Connected lookup caches all lookup columns

Unconnected lookup caches only the lookup output ports in the lookup conditions and the return port Supports user-defined default values (i.e. value to return when lookup conditions Does not support user defined default values are not satisfied)

What is the difference between Router and Filter?

Router transformation divides the incoming records into multiple groups based on some condition. Such groups can be mutually inclusive (Different groups may contain same record) Filter transformation restricts or blocks the incoming record set based on one given condition. Router transformation itself does not block any record. If a certain record does not match any of the routing conditions, the record is routed to default group Filter transformation does not have a default group. If one record does not match filter condition, the record is blocked Router acts like CASE.. WHEN statement in SQL (Or Switch ()... Case statement in C) Filter acts like WHERE condition is SQL.

What can we do to improve the performance of Informatica Aggregator Transformation?

Aggregator performance improves dramatically if records are sorted before passing to the aggregator and "sorted input" option under aggregator properties is checked. The record set should be sorted on those columns that are used in Group By operation. It is often a good idea to sort the record set in database level e.g. inside a source qualifier transformation, unless there is a chance that already sorted records from source qualifier can again become unsorted before reaching aggregator 

What is the different lookup cache?

Lookups can be cached or un cached (No cache). Cached lookup can be either static or dynamic.

A static cache is one which does not modify the cache once it is built and it remains same during the session run. On the other hand,

 A dynamic cache is refreshed during the session run by inserting or updating the records in cache based on the incoming source data. A lookup cache can also be divided as persistent or non-persistent based on whether Informatica retains the cache even after session run is complete or not respectively

How can we update a record in target table without using Update strategy?

A target table can be updated without using 'Update Strategy'. For this, we need to define the key in the target table in Informatica level and then we need to connect the key and the field we want to update in the mapping Target. In the session level, we should set the target property as "Update as Update" and check the "Update" check-box. Let's assume we have a target table "Customer" with fields as "Customer ID", "Customer Name" and "Customer Address". Suppose we want to update "Customer Address "without an Update Strategy. Then we have to define "Customer ID" as primary key in Informatica level and we will have to connect Customer ID and Customer Address fields in the mapping. If the session properties are set correctly as described above, then the mapping will only update the customer address field for all matching customer IDs