Use the Tablespaces Page, Datafiles Page, and Segment Page to view the logical and physical structures that have the highest rates of I/O activity in the database.
Tablespaces are the logical structures that contain the datafiles and segments that make up a database.
Data in this drilldown is derived from V$IOSTAT_FILE (Oracle 11g and later) or from V$FILESTAT and V$TEMPSTAT (Oracle 10g).
To open the Tablespaces page
Select the Spotlight on Oracle RAC connection in the Spotlight Browser.
Click I/O | Tablespaces.
Charts on the Tablespaces Page
| Chart | Description |
|---|---|
| Throughput - requests (Top 20) |
Throughput—Requests shows the rate of I/O requests for the top 20 tablespaces (by total requests) in the database. The rate is measured by the number of physical I/O requests per second. Values that are consistently high over the displayed period are those most likely to contribute to performance bottlenecks. |
| Latency (Top 20) |
For the top 20 tablespaces (by total requests) with the highest rate of I/O requests, Latency shows the average time (in milliseconds) taken to process a physical I/O request on each tablespace. Values that are consistently high over the displayed period are those most likely to contribute to performance bottlenecks. |
The Tablespaces grid
The Tablespaces grid shows information about I/O activity on the tablespaces in the Oracle database.
By default, the grid is ordered by the Requests/s column to show which tablespaces are being used the most. High values in the Read latency (ms) column may indicate potential bottlenecks.
Note: Tablespaces contain the physical datafiles that make up an Oracle database. Any given datafile can belong to only one tablespace. To view details of the datafiles within a specified tablespace right-click a row in the Tablespaces grid and select Show Data Files to open the I/O | Datafiles Page.
| Column | Description |
|---|---|
|
Tablespace name |
The name of the tablespace. |
|
Read Latency (ms) |
The average time taken to perform a read request on the tablespace. Note: A zero value in this column indicates a tablespace that is currently idle. |
|
Requests/s |
The rate of read requests on the tablespace. |
|
Read Requests |
The total number of read requests on the tablespace since instance startup. |
|
Write Requests |
The total number of write requests on the tablespace since instance startup. |
|
Read Time (s) |
The total time taken to perform read requests on the tablespace since instance startup. |
|
Write Time (s) |
The total time taken to perform write requests on the tablespace since instance startup. |
|
Read Megabytes |
The number of megabytes of data read from the tablespace since instance startup. |
|
Write Megabytes |
The number of megabytes of data written to the tablespace since instance startup. |
|
Write Latency (ms) |
The average time taken to perform a write request on the tablespace. |
