SELECT 
	filename, 
	status, 
	bytes
FROM v$block_change_tracking;

SELECT 
	file#, 
	avg(datafile_blocks),
	avg(blocks_read),
	avg(blocks_read/datafile_blocks) * 100 AS PCT_READ_FOR_BACKUP,
	avg(blocks)
FROM 
	v$backup_datafile
WHERE 
	used_change_tracking = 'YES'
AND incremental_level > 0
GROUP BY file#;