1. What is ETL
Answer: An ETL tool extracts the data from these heterogeneous data source, transform the data like applying some calculation, joining fields, keys, removing incorrect data fields etc. and a load it into a data warehouse.
2. What is the difference between ETL tool and OLAP tools
Answer:
ETL tool is meant for extraction data from the legacy systems and load into specified database with some process of cleansing data X Informatica data stage OLAP is meant for reporting purpose in OLAP data available in multi-directional model so that you can write simple query to extract data from the database X Business Objects Cognos
3. What is odes operation data source
Answer: ODS operational data store ODS comes between staging area and data warehouse the data is ODS will be at the low level of granularity once data was populated in ODS aggregated data will be loaded into EDW through ODS.
4. Where do we use connected and unconnected lookups
Answer: if returned port only 1 then we can go for unconnected more than 1 returned port is not possible with unconnected if more than one returned port then go for connected if you require dynamic cache an ie where your data will change dynamically then you can go for connected lookup if your data is static where your data won't change when the session loads you can go for unconnected lookups.
5. Where do we use semi and non-additive facts
Answer: Additive a measure can participate arithmetic calculations using all or any dimensions semi additive a measure can participate arithmetic calculations using some dimensions non-additive a measure can't participate arithmetic calculations using dimensions.
6. What is the latest version of power center power Mart?
Answer: the latest version is 7.2
7. What are the modules in power Mart?
Answer: Power mod designer server manager repository manager.
8. what are active transformation, passive transformations?
Answer: active transformation can change the number of rows that pass through it decrease or increase rows passive transformation cannot change the number of rows that pass through it
9. What are the different lookup methods used in Informatica
Answer: connected lookup connected look up will receive input from the pipeline and sends output to the pipeline and can return any number of values it does not contain return port unconnected lookup can return only one column it contained return port
10. Can Informatica load heterogeneous targets from heterogeneous sources
Answer: nor in Informatica 5.2 and yes in Informatica 6.1 and later
11. How do we call shell scripts from Informatica
Answer: specify the full path of the shell script a post session properties of session workflow.
12. what is Informatica metadata and where its stored.
Answer: Informatica metadata is data about data which stores in Informatica repositories.
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