面试题与答案

Informatica PowerCenter is an ETL (Extract, Transform, Load) tool used for data integration and warehousing.

A session in Informatica is a task that represents the execution of a workflow. It is the smallest unit of work in a workflow.

A repository in Informatica is a relational database that stores metadata and configuration information about the various objects managed by Informatica.

A workflow in Informatica is a set of instructions for the integration service to execute the tasks defined in a mapping.

The Aggregator transformation in Informatica is used to perform aggregate calculations such as sum, average, minimum, maximum, etc., on groups of data.

The Sequence Generator transformation in Informatica is used to generate unique sequence numbers for rows in a data set.

Informatica supports various transformations, including Aggregator, Filter, Router, Lookup, Expression, Joiner, and many others.

The Source Qualifier transformation in Informatica is used to specify properties for reading data from a relational or flat file source.

A Filter transformation in Informatica is used to filter rows based on specified conditions, allowing only the required rows to pass through.

A Parameter File in Informatica is a text file that contains parameter values used to replace placeholders in session and workflow properties at runtime.

A Router transformation in Informatica is used to filter data rows to different output groups based on specified conditions.

A reusable session in Informatica can be created by defining the session as reusable in the session properties and saving it to the repository for use in multiple workflows.

Null values in Informatica can be handled using functions like ISNULL and COALESCE, or through the use of NULL indicator ports in transformations.

A Joiner transformation in Informatica is used to combine rows from two heterogeneous sources based on a common column, similar to an SQL join operation.