Latches Page
Latches shows latch statistics information for all latches that have ever been used.
To open the Latches page
- Select the Spotlight on Oracle connection in the Spotlight Browser.
-
Click Activity | Latches.
Latch Activity Grid
Shows absolute get, miss, and sleep rates for each latch in the instance.
| Column | Description |
|---|---|
|
Latch name |
The name, or a brief description of, the latch. |
|
Latches |
The number of instances of this latch that have ever been used. |
|
Gets/s |
The rate at which the latch is obtained. |
|
% Gets |
100 * (latch gets for a particular latch) / (total latch gets for all latches) This value is NOT calculated as a percentage of total gets for a particular latch. |
|
Sleeps/s |
The rate at which sleeps occurred when a latch was attempted. |
|
% Sleeps |
100 * (latch sleeps for a particular latch) / (total latch sleeps for all latches) This value is NOT calculated as a percentage of total sleeps for a particular latch. |
|
Sleep rate |
( Sleeps * 100 ) / Gets |
|
Misses/s |
The rate at which the first try to obtain the latch failed. |
|
% Misses |
100 * (latch misses for a particular latch) / (total latch misses for all latches) This value is NOT calculated as a percentage of total misses for a particular latch. |
|
Miss rate |
( Misses * 100 ) / Gets |
| Latch Category |
The category this latch belongs to. |
Charts on the Latches Page
| Chart | Description |
|---|---|
| Latch rate | The Latch rate chart shows the get, miss, and sleep rate for various categories of latch. Use the drop-down list to display get, miss, or sleep rates. |
| Latch efficiency | The Latch efficiency chart shows the absolute latch miss and sleep rates (as proportions of the get rate) and the percentage of non-idle event wait times that are due to latch sleeps. |