Informatica Interview Questions on Sequence Generator Transformation

1. What is a sequence generator transformation?

A Sequence generator transformation generates numeric values. Sequence generator transformation is a passive transformation.

2. What is the use of a sequence generator transformation?

A sequence generator is used to create unique primary key values, replace missing primary key values or cycle through a sequential range of numbers.

3. What are the ports in sequence generator transformation?

A sequence generator contains two output ports. They are CURRVAL and NEXTVAL.

4. What is the maximum number of sequence that a sequence generator can generate?

The maximum value is 9,223,372,036,854,775,807

5. When you connect both the NEXTVAL and CURRVAL ports to a target, what will be the output values of these ports?

The output values are
NEXTVAL  CURRVAL
1        2
2        3
3        4
4        5
5        6

6. What will be the output value, if you connect only CURRVAL to the target without connecting NEXTVAL?

The integration service passes a constant value for each row.

7. What will be the value of CURRVAL in a sequence generator transformation?

CURRVAL is the sum of "NEXTVAL" and "Increment By" Value.

8. What is the number of cached values set to default for a sequence generator transformation?

For non-reusable sequence generators, the number of cached values is set to zero.
For reusable sequence generators, the number of cached values is set to 1000.

9. How do you configure a sequence generator transformation?

The following properties need to be configured for a sequence generator transformation:

• Start Value
• Increment By
• End Value
• Current Value
• Cycle
• Number of Cached Values