Exports a table. The tables data is not exported, just table metadata and a list of files to distcp. The table being exported must be offline and stay offline for the duration of distcp. To avoid losing access to a table it can be cloned and the clone taken offline for export.
See docs/examples/README.export
@param tableName Name of the table to export.
@param exportDir An empty directory in HDFS where files containing table metadata and list of files to distcp will be placed.
@since 1.5.0