Peak Processing Periods
The activity on an Oracle database changes according to many factors, including the number of users logged on to the database and the type of processing performed. Database performance can suffer at times of peak activity if there are not enough database resources available to handle that activity.
Use the Peak Processing Periods page to:
- Identify when the Oracle database experiences times of peak activity.
- Limit Predictive Diagnostics to analyzing data from those peak periods only.
The result is a more precise prediction that relates only to the times when the database is heavily loaded.
Notes:
- Peak Processing Periods are used when identifying database bottlenecks and modeling database performance. Predictive Diagnostics does NOT use defined peak periods when identifying degrading SQL.
- Set peak periods for real data and sample data separately.
To open the page
- Select the Spotlight on Oracle connection in the Spotlight Browser.
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Click Predictive Diagnostics | Identify the peak-activity periods of the database.
Set the criteria
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Control |
Description | ||||||||||
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Show database processing activity for... |
Select Real Data (your database) or Sample Data (to experiment with). Note: Spotlight takes some time (typically about 10 days) to collect enough data to make valid predictions on the future performance of your Oracle instance. In the meantime use the prepared sample data to learn more about Predictive Diagnostics and how it works. | ||||||||||
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Between...and... |
Select start and end dates for the analysis. The period of time should:
The default period is the previous seven days. The chosen period is shown in the Database Processing Activity chart on the right. | ||||||||||
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Using... |
Select one or more metrics to represent the database activity. Throughput Metrics
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Database Processing Activity chart
This is a graphical view of the selected criteria. It shows the raw data for each metric selected when setting the criteria.
Notes:
- Select Normalize data displayed to ensure the peaks and troughs of all series in the Database Processing Activity chart can be displayed simultaneously at a usable scale. Predictive Diagnostics plots data points on the chart by translating the linear scale on the Y-axis to a logarithmic scale where:
- Zero represents the average value of all points in a data series.
- The scale on the Y-axis (-3 to 3) represents standard deviations away from that average.
- Every chart has a legend (list of symbols) to its right that describes the various series (line graphs) on the chart.
- Click an item in the legend to highlight its series (line) in the chart. Click a second time to return the series to its normal appearance.
- Move the mouse pointer over an item in the legend to view the current value for that series within the chart.
Define peak periods to Predictive Diagnostics
Use the Peak Processing Periods table to select or create a weekly set of peak activity periods for your prediction.
Note: A period of "peak activity" will not always be a time when total activity is at its maximum. For example, users may set separate peak periods for online and batch processing:
- Online peak: A high-activity period corresponding to online activity (mainly during office hours).
- Batch processing: A period overnight where a small number of scheduled transactions move large amounts of data on a regular basis. The load experienced during batch operations is mostly caused by I/O, so database I/O limits may be exceeded during batch operations before they are exceeded during the online peak.
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Action |
Description |
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Set which peak period to use by default |
Locate the period (row) you want to use as default. Click the Default option. To display the peak period on the Database Processing Activity chart, select the corresponding Preview option. Use this to confirm visually that the period selected aligns with actual peak loads. |
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Add a new time to an existing period |
Right-click a row in the table and select Add new time. Click each cell in the new row to edit that cell. |
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Delete a time from an existing period |
Right-click a row in the table and select Remove time. |
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Add a new period |
Click Define Period.
OR
Right-click in the table and select Add new processing period. |
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Add a new period based on an existing period |
Click the down-arrow next to Define Period and select a period type from the list.
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Delete a period |
Select a period in the table and click Remove Period.
OR
Right-click a period in the table and select Remove processing period. |
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Revert to previous values |
Click Revert Changes.
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The Peak Processing Period grid
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Column |
Description |
|---|---|
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Processing Period |
A short description of what the processing period represents. This description is used on Predictive Diagnostics drilldown pages that use Peak Periods such as Impending Bottlenecks - Timed Statistics. |
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Default |
The default period selected on Predictive Diagnostics drilldown pages that use Peak Periods such as Impending Bottlenecks - Timed Statistics. |
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Start |
When the processing period starts. |
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Finish |
When the processing period ends. Note: If the Finish day is set to a value earlier than the Start day, it is interpreted as the corresponding time on the following week. |
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Preview |
Display this period in the Database Processing Activity chart. Tip: Use this to confirm visually that the period selected aligns with actual peak loads. |