Parameter and Command Reference > Parameters Common to CFS Connectors > General Connector Parameters > EnableExtractionCopy

Generally, this parameter is only relevant to the File System Connector, that is acting on the original documents instead of temporary copies. When performing extraction from certain file types, KeyView has side-effects that mean that the document is updated. This specifically causes the modified date to be updated and will thus cause the connector to re-ingest the document on the next synchronize action.
To avoid these modifications, the solution is to make a copy of the original document (by setting this parameter to True) and perform the extraction on the copy.
For other connectors, enabling this setting will have no effect, since the connectors will be downloading temporary copies and will have ownership of the files.