V$DATAFILE_HEADER displays datafile information from the datafile headers.

Column Datatype Description
FILE# NUMBER Datafile number (from control file)
STATUS VARCHAR2(7) ONLINE | OFFLINE (from control file)
ERROR VARCHAR2(18) NULL if the datafile header read and validation were successful. If the read failed then the rest of the columns are NULL. If the validation failed then the rest of columns may display invalid data. If there is an error then usually the datafile must be restored from a backup before it can be recovered or used.
FORMAT NUMBER Indicates the format for the header block. The possible values are 6, 7, 8, or 0.

6 - indicates Oracle Version 6

7 - indicates Oracle Version 7

8 - indicates Oracle Version 8

0 - indicates the format could not be determined (for example, the header could not be read)

RECOVER VARCHAR2(3) File needs media recovery (YES | NO)
FUZZY VARCHAR2(3) File is fuzzy (YES | NO)
CREATION_CHANGE# NUMBER Datafile creation change#
CREATION_TIME DATE Datafile creation timestamp
TABLESPACE_NAME VARCHAR2(30) Tablespace name
TS# NUMBER Tablespace number
RFILE# NUMBER Tablespace relative datafile number
RESETLOGS_TIME DATE Resetlogs timestamp
CHECKPOINT_CHANGE# NUMBER Datafile checkpoint change#
CHECKPOINT_TIME DATE Datafile checkpoint timestamp
CHECKPOINT_COUNT NUMBER Datafile checkpoint count
BYTES NUMBER Current datafile size in bytes
BLOCKS NUMBER Current datafile size in blocks
NAME VARCHAR2(513) Datafile name
SPACE_HEADER VARCHAR2(40) The amount of space currently being used and the amount that is free, as identified in the space header
LAST_DEALLOC_SCN VARCHAR2(16) Last deallocated SCN