Rules and Guidelines for Mappings on the Databricks Spark Engine
Rules and Guidelines for Mappings on the Databricks Spark Engine
A non-native environment like Databricks Spark 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 runtime engine might not be able to determine the order in which the data originated. So, when you run a mapping in a non-native environment and you run the same mapping in the native environment, both mappings return correct results, but the results might not be identical. For more information, see the
Consider the following run-time differences on the Databricks Spark engine:
When you use the auto optimizer level, the early selection optimization method is enabled if the mapping contains any data source that supports pushing filters to the source on Spark or Databricks Spark engines. For more information about optimizer levels, see the
Informatica Developer Mapping Guide
.
Databricks Spark performs auto-optimization on jobs based on configuration settings for the cluster. If you set optimization through the Spark.default.parallelism property, the Databricks Spark engine ignores this setting. As a consequence, it is not possible to configure optimization on the job level.