| SNAP_ID | NUMBER |  | Unique snapshot ID | 
| DBID | NUMBER |  | Database ID for the snapshot | 
| INSTANCE_NUMBER | NUMBER |  | Instance number for the snapshot | 
| FILE# | NUMBER |  | File identification number | 
| CREATION_CHANGE# | NUMBER |  | Change number at which the datafile was created | 
| FILENAME | VARCHAR2(513) |  | Name of the datafile | 
| TS# | NUMBER |  | Tablespace number | 
| TSNAME | VARCHAR2(30) |  | Name of the tablespace | 
| BLOCK_SIZE | NUMBER |  | Block size of the datafile | 
| PHYRDS | NUMBER |  | Number of physical reads done | 
| PHYWRTS | NUMBER |  | Number of times DBWR is required to write | 
| SINGLEBLKRDS | NUMBER |  | Number of single block reads | 
| READTIM | NUMBER |  | Time (in hundredths of a second) spent doing reads if the TIMED_STATISTICSparameter istrue;0ifTIMED_STATISTICSisfalse | 
| WRITETIM | NUMBER |  | Time (in hundredths of a second) spent doing writes if the TIMED_STATISTICSparameter istrue;0ifTIMED_STATISTICSisfalse | 
| SINGLEBLKRDTIM | NUMBER |  | Cumulative single block read time (in hundredths of a second) | 
| PHYBLKRD | NUMBER |  | Number of physical blocks read | 
| PHYBLKWRT | NUMBER |  | Number of blocks written to disk, which may be the same as PHYWRTSif all writes are single blocks | 
| WAIT_COUNT | NUMBER |  | Wait Count | 
| TIME | NUMBER |  | Wait Time |