10 DataStage Interview Questions and Answers - Download PDF

10 DataStage Interview Questions and Answers

1) What is Datastage ?
2) What are the differences between Datastage and Informatica
3) How do you generate Sequence number in Datastage?
4) What are the components of DataStage?
5) What is a merge in DataStage?
6) What are system variables and sequencers in DataStage
7) What is the difference between operational data stage (ODS) and data warehouse?
8) Purpose of Pivot Stage and types of containers in DataStage
9) What can we do with DataStage Director?
10) What is the difference between data warehousing and OLAP?

1) What is Datastage ?

• Design jobs for Extraction, Transformation and Loading(ETL).
• Ideal tool data integration projects such as data warehouses, data marts and system migrations
• import, export, create and managed metadata for use within jobs.
• Schedule, run and monitor jobs all withinDatastge
• Adminsters your Datastage development and execution environments.

2) What are the differences between Datastage and Informatica

• Data stage supports parallel processing
• Links are treated as objects in Data Stage
• Links are port to port connectivity in Informatica
• The implementation of Slowly Changing Dimensions is easy in Informatica which are complex in Data Stage
• Complete error handling is not supported by informatica, which is supported Datastage.

3) How do you generate Sequence number in Datastage?

Sequence numbers can be generated in Datastage using certain routines. They are

• KeyMgtGetNextVal
• KeyMgtGetNextValConn

4) What are the components of DataStage?

Datastage has two components

• Client Components – Designer, Director, Manager and Administrator
• Server Components – Server, Repository and Plug-ins.

5) What is a merge in DataStage?

Merge in DataStage :

• is available in both parallel an server jobs as a specific stage
• is used for the purpose of joining two tables such as server/parallel or tables/datasets
• is done on a key field which is mandatory in both master and update dataset

6) What are system variables and sequencers in DataStage

 System variables:

• System variables are used to get system information
• They are accessed by a transformer or by a routine
• They have @ as prefix and are read only

Sequencers:

• Sequencers allows for synchronizing the control flow of various activities in a single sequence of jobs.
• The number of input and output triggers can be multiple

7) What is the difference between operational data stage (ODS) and data warehouse?

Data warehouse

• It is a decision support database system for the purpose of organizational needs. 
• It is non volatile, integrated and time variant collection of data

Operational Data Source

• It is an integrated collection of information. 
• It can contain 90 days of information at maximum.
• ODS supports dynamic data.

8) Purpose of Pivot Stage and types of containers in DataStage

What is the purpose of Pivot Stage?

Pivot Stage is used to convert columns to rows

What are the types of Containers?

There are two types of containers namely, Local Container and Shared Container

9) What can we do with DataStage Director?

• Validating
• Scheduling
• Executing
• Monitoring server jobs

10) What is the difference between data warehousing and OLAP?

• Data warehouse refers to organization and data storage from various resources
• Data warehousing is used for data analysis. 
• OLAP is to deal with data analysis with a software 
• OLAP is used for managing aggregations and information partition for in-depth analysis
• Business intelligence is performed with OLAP.