Consider the following rules and guidelines for Cassandra Connector:
Transformation errors appear in the session log even if the mapping does not contain any transformations.
Workaround: You can ignore the transformation errors.
Column names of a MongoDB data object cannot exceed 255 characters.
When you refresh a MongoDB data source in the
Import Tables
dialog box, the dropped MongoDB collections still appear.
The virtual tables appear in the
Import Tables
dialog box only when you import the table metadata.
When you create a mapping and specify special characters or white spaces in the source or target name, the mapping fails.
When you run a mapping with a Joiner transformation to read from a MongoDB database prior to version 2.6.3, the following error might appear in the mapping log even if the nested element is not null: LEFT_SUBFIELD only supports Object.