4.340 DBA_HIST_IOSTAT_FUNCTION

DBA_HIST_IOSTAT_FUNCTION displays historical I/O statistics by function.

This view contains snapshots of V$IOSTAT_FUNCTION.

Column Datatype NULL Description

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

FUNCTION_ID

NUMBER

NOT NULL

Function ID

FUNCTION_NAME

VARCHAR2(128)

NOT NULL

Function name

SMALL_READ_MEGABYTES

NUMBER

NOT NULL

Number of single block megabytes read

SMALL_WRITE_MEGABYTES

NUMBER

NOT NULL

Number of single block megabytes written

LARGE_READ_MEGABYTES

NUMBER

NOT NULL

Number of multiblock megabytes read

LARGE_WRITE_MEGABYTES

NUMBER

NOT NULL

Number of multiblock megabytes written

SMALL_READ_REQS

NUMBER

NOT NULL

Number of single block read requests

SMALL_WRITE_REQS

NUMBER

NOT NULL

Number of single block write requests

LARGE_READ_REQS

NUMBER

NOT NULL

Number of multiblock read requests

LARGE_WRITE_REQS

NUMBER

NOT NULL

Number of multiblock write requests

NUMBER_OF_WAITS

NUMBER

NOT NULL

Number of I/O waits by functionality

WAIT_TIME

NUMBER

NOT NULL

Total wait time (in milliseconds)

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

See Also:

"V$IOSTAT_FUNCTION"