Enqueue Monitor 

Definition

This submonitor in the SAP/Oracle Database Monitor helps you monitor enqueues and so reduce wait events.

Use

You choose Detailed Analyses ®  Exceptional Conditions ® Enqueue Monitor.

Entries marked “RAC only” are only relevant for Oracle Real Application Cluster (RAC).

You can view history information in this monitor.

Structure

·        v$enqueue stat

This tab page contains the following information:

Column	Description
Instance Id RAC only	Database instance ID
Enqueue Type	Type of enqueue requested
Total Requests	Total number of enqueue requests or enqueue conversions for this type of enqueue
% Requests	Requests for this enqueue type as a percentage of total requests
Total Waits	Total number of times an enqueue request or conversion resulted in a wait
%Wai… – % Waits	Waits for this enqueue type as a percentage of total waits
Total Gra… – Total Grants	Number of times an enqueue request or conversion was granted
% Grants	Grants for this enqueue type as a percentage of total requests
Total Fails	Number of times an enqueue request or conversion failed
% Fails	Fails for this enqueue type as a percentage of total fails
Cum. Wait Ti… – Cumulative Wait Time	Cumulative (that is, total) amount of time in milliseconds spent waiting for the enqueue or enqueue conversion
% Wait Time	Wait time for this enqueue type as a percentage of total wait time
% Wait / Upti… – % Wait / Uptime	Cumulative wait time for this enqueue type as a percentage of the total database uptime

¡        Generating totals

For numeric columns, you can select the column and choose Total to generate totals. For example, you can generate totals for the column Total Requests.

¡        Generating subtotals

For the non-numeric columns you can select the column and choose Subtotals to generate subtotals. For example, you can generate subtotals for the column Enqueue Type.

·        RAC only: v$enqueue stat  with Total Lines

This tab page appears only for RAC systems when you are monitoring the whole system, that is, you have selected Total under DB Instances.

The tab page displays the same information as in the table above plus total lines for all instances, marked with Instance ID set to zero.

Integration

This monitor is based on the view GV$ENQUEUE_STAT.