Segment Page
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.
Within a tablespace, a segment is a database object that consumes storage. Examples of segments are tables, indexes, rollback segments, and temporary segments.
Data for the Segment drilldown is derived from V$SEGMENT_STATISTICS.
To open the Segment Page
-
Select the Spotlight on Oracle RAC connection in the Spotlight Browser.
-
Click I/O | Segment.
Segments Grid
The Segment table shows the Top 100 database segments – the segments that currently have the highest total physical I/O – in the current database instance. The Top 100 is sorted first in descending order by total physical I/O, and then by logical reads in ascending order.
Notes:
- Highlight a row of the Segments Grid to open I/O Segment Details.
- Not all columns are visible by default. Use the Column Organizer to view hidden columns. Show, Hide & Order Columns
| Column | Description |
|---|---|
|
Object |
The name of the segment and its owner. |
|
Total Physical IO |
The sum of physical reads, direct physical reads, physical writes, and direct physical writes on the segment in the current instance. |
|
Logical Reads |
The number of logical reads on the segment. |
|
Physical Reads |
The number of physical reads on the segment. |
|
Physical Reads Direct |
The number of direct physical reads on the segment. |
|
Physical Writes |
The number of physical writes on the segment. |
|
Physical Writes Direct |
The number of direct physical writes on the segment. |
|
Buffer Busy Wait |
The number of Buffer Busy waits on this segment. To view the number of Buffer Busy waits for the instance, go to the Activity | Buffer Busy Waits Page. |
|
DB Block Changes |
The number of DB block changes on the segment. |
|
GC CR Blocks |
The number of Global Cache Consistent Read blocks served in the current instance. |
|
GC Current Blocks |
The number of Global Cache Current blocks served. |
|
ITL Waits |
Interested Transaction List waits on the segment. The ITL slots are controlled by the INITRANS and MAXTRANS values for the segment. If the number of ITL waits is too high, increase the INITRANS and/or MAXTRANS values. |
|
Row Lock Waits |
The number of Row Lock waits. |