Explain error handling in informatica with examples?
There is one file called the bad file which generally has the format as *.bad and it contains the records rejected by informatica server. There are two parameters one for the types of row and other for the types of columns. The row indicators signify what operation is going to take place (i.e. insertion, deletion, updating etc.). The column indicators contain information regarding why the column has been rejected. (Such as violation of not null constraint, value error, overflow etc.) If one rectifies the error in the data present in the bad file and then reloads the data in the target, then the table will contain only valid data.
What is power center repository?
Standalone repository: A repository that functions individually, unrelated and unconnected to
other repositories.
Global repository: (Power Center only.) The centralized repository in a domain, a group of
connected repositories. Each domain can contain one global repository. The global repository can contain common objects to be shared throughout the domain through global shortcuts.
Local repository. (Power Center only.) A repository within a domain that is not the global repository. Each local repository in the domain can connect to the global repository and use objects in its shared folders.
Explain difference between static and dynamic cache with one example?
Static Cache: Once the data is cached, it will not change. Example unconnected lookup uses
static cache.
Dynamic Cache: The cache is updated as to reflect the update in the table (or source) for
which it is referring to. (Ex. connected lookup).
What is update strategy transformation?
The model you choose constitutes your update strategy, how to handle changes to existing rows. In Power Center and Power Mart, you set your update strategy at two different levels:
Within a session. When you configure a session, you can instruct the Informatica Server to either treat all rows in the same way (for example, treat all rows as inserts), or use instructions coded into the session mapping to flag rows for different database operations.
Within a mapping. Within a mapping, you use the Update Strategy transformation to flag rows for insert, delete, update, or reject.
Explain Informatica server Architecture?
Informatica server, load manager/rs,data transfer manager,reader,temp server and writer are the components of informatica server. First load manager sends a request to the reader if the reader is ready to read the data from source and dump into the temp server and data transfer manager manages the load and it send the request to writer as per first in first out process and writer takes the data from temp server and loads it into the target.
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 you do not choose data driven option setting, the informatica server ignores all update strategy
transformations in the mapping.
How the informatica server sorts the string values in Rank transformation?
We can run informatica server either in UNICODE data moment mode or ASCII data moment mode.
Unicode mode: In this mode informatica server sorts the data as per the sorted order in
session.
When do you use an unconnected lookup and connected lookup?
Or
what is the difference between dynamic and static lookup?
Or
Why and when do we use dynamic and static lookup?
In static lookup cache, you cache all the lookup data at the starting of the session. In dynamic lookup cache, you go and query the database to get the lookup value for each record which needs the lookup. Static lookup cache adds to the session run time, but it saves time as
informatica does not need to connect to your database every time it needs to lookup. Depending on how many rows in your mapping needs a lookup, you can decide on this. Also remember that static lookup eats up space. so remember to select only those columns which are needed.
How do we do unit testing in informatica? How do we load data in informatica?
Unit testing in informatica are of two types 1. Quantitative testing
2. Qualitative testing
Steps:
1. First validate the mapping
2.Create session on the mapping and then run workflow.
Once the session is succeeded then right click on session and go for statistics tab.There you can see how many numbers of source rows are applied and how many number of rows loaded in to targets and how many number of rows rejected. This is called Quantitative testing.
If once rows are successfully loaded then we will go for qualitative testing.
Steps:
1.Take the DATM (DATM means where all business rules are mentioned to the corresponding source columns) and check whether the data is loaded according to the DATM in to target table. If any data is not loaded according to the DATM then go and check in the code and rectify it.
This is called Qualitative testing.This is what a developer will do in Unit Testing.