Transformations in the Native and Hadoop Environments
Mappings that run in the Hadoop environment can return different results than mappings that run in the native environment.
Consider the following processing differences:
- •Hadoop uses distributed processing and processes data on different nodes. Each node does not have access to the data that is being processed on other nodes. As a result, the Hadoop execution engine might not be able to determine the order in which the data originated. So, when you run a mapping in a Hadoop environment and you run the same mapping in the native environment, both mappings return correct results, but the results might not be identical.
- •Each of the run-time engines in the Hadoop environment can process mapping logic differently. In the Hadoop environment, Informatica transformations might be fully supported, supported with restrictions, or not supported. Similarly, in the native environment, some Informatica transformations and transformation behavior might not be supported.
Before you validate and run a mapping in the Hadoop environment, refer to the Big Data Management User Guide to learn about the transformations that are supported in the Hadoop environment and the processing restrictions.