This function provides a way to add a new segment to the index referenced by the Handle parameter based on the $ROWID$ field:
ctdbAddRowIdSegment(CTHANDLE Handle);
This allows a part of the index to include a segment containing the internal ROWID field value.
Once such a segment exists, the table creation may fail with error CTDBRET_ROWIDSEG indicating an attempt to create an index with ROWID reference on a table with no ROWID support.