FILE_IOSTAT

Records statistics about data file I/Os to indicate I/O performance and detect performance problems such as abnormal I/O operations, as shown in Table 1. In the multi-tenancy scenario, global information is returned if this view is accessed in a non-PDB, and information about a PDB is returned if this view is accessed in the PDB. The I/O statistics queried through this view in the PDB are not persisted and are cleared after the database is restarted.

**Table 1** FILE_IOSTAT columns
Name	Type	Description
filenum	oid	File identifier.
dbid	oid	Database ID.
spcid	oid	Tablespace ID.
phyrds	bigint	Number of times of reading physical files.
phywrts	bigint	Number of times of writing into physical files.
phyblkrd	bigint	Number of times of reading physical file blocks.
phyblkwrt	bigint	Number of times of writing into physical file blocks.
readtim	bigint	Total duration of reading (unit: μs).
writetim	bigint	Total duration of writing (unit: μs).
avgiotim	bigint	Average duration of reading and writing (unit: μs).
lstiotim	bigint	Duration of the last file reading (unit: μs).
miniotim	bigint	Minimum duration of reading and writing (unit: μs).
maxiowtm	bigint	Maximum duration of reading and writing (unit: μs).