Default: n
To import only data (no metadata) from a dump file, specify DATA_ONLY=y.
When you specify DATA_ONLY=y, any import parameters related to metadata that are entered on the command line (or in a parameter file) become invalid. This means that no metadata from the dump file will be imported.
The metadata-related parameters are the following: COMPILE, CONSTRAINTS, DATAFILES, DESTROY, GRANTS, IGNORE, INDEXES, INDEXFILE, ROWS=n, SHOW, SKIP_UNUSABLE_INDEXES, STATISTICS, STREAMS_CONFIGURATION, STREAMS_INSTANTIATION, TABLESPACES, TOID_NOVALIDATE, TRANSPORT_TABLESPACE, TTS_OWNERS.