When the Data Integration Service uses the Hive engine, it has a Hive executor that can process the mapping. The Hive executor simplifies the mapping to an equivalent mapping with a reduced set of instructions and generates a Hive execution plan.
The Hive execution plan is a series of Hive queries. The Hive execution plan contains tasks to start the mapping, run the mapping, and clean up the temporary tables and files. You can view the Hive execution plan that the Data Integration Service generates before you run the mapping.
When the Data Integration Service uses the Blaze engine, it has a Blaze engine executor that can process the mapping. The Blaze engine executor simplifies the mapping to segments and generates a Blaze engine execution plan. Each segment can contain multiple tasklets. Each tasklet can contain multiple partitions.
The Blaze engine execution plan contains tasks to start the mapping, run the mapping, and clean up the temporary tables and files. It contains the number of tasklets in a mapping, tasklet details, and the task recovery strategy. It also contains pre and post grid task preparation commands for each mapping before running the main mapping on a Hadoop cluster. A pre-grid task can include a task such as copying data to HDFS. A post-grid task can include tasks such as cleaning up temporary files or copying data from HDFS.