SNAP_ID

NUMBER

NOT NULL

Unique snapshot ID

DBID

NUMBER

NOT NULL

Database ID for the snapshot

INSTANCE_NUMBER

NUMBER

NOT NULL

Instance number for the snapshot

FILE#

NUMBER

NOT NULL

File identification number

CREATION_CHANGE#

NUMBER

NOT NULL

Change number at which the data file was created

FILENAME

VARCHAR2(513)

NOT NULL

Name of the data file

TS#

NUMBER

NOT NULL

Tablespace number

TSNAME

VARCHAR2(30)

Name of the tablespace

BLOCK_SIZE

NUMBER

Block size of the data file

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_STATISTICS parameter is true; 0 if TIMED_STATISTICS is false

WRITETIM

NUMBER

Time (in hundredths of a second) spent doing writes if the TIMED_STATISTICS parameter is true; 0 if TIMED_STATISTICS is false

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 PHYWRTS if all writes are single blocks

WAIT_COUNT

NUMBER

Shows the number of waits at the file level for contended buffers. This value includes the individual wait events that are included in the buffer busy waits wait event.

See Also: "buffer busy waits"

TIME

NUMBER

Time spent waiting for the wait events in the WAIT_COUNT column

OPTIMIZED_PHYBLKRD

NUMBER

Number of physical reads from Database Smart Flash Cache blocks

CON_DBID

NUMBER

The database ID of the PDB for the sampled session

CON_ID

NUMBER

The ID of the container that CON_DBID identifies. Possible values include:

• 0: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs.

• 1: This value is used for rows containing data that pertain to only the root

• n: Where n is the applicable container ID for the rows containing data