Capacity Usage Viewer

PCC provides Capacity Usage Viewer to monitor concurrent sessions and data usage for all database engines. This is especially useful when you are considering migrating from PSQL Server to PSQL Vx Server, because of the difference in the way those two editions are licensed. PSQL Server licenses are based on the number of users, while PSQL Vx Server licenses are based on the number of concurrent sessions and the amount of data in use.

Capacity Usage Viewer includes two graphs, one for the number of concurrent sessions and one for the amount of data. Each graph includes a usage level bar, a heavy horizontal line across the graph, to help you determine what volume of usage is normal and what volume is uncommon for your business. The Capacity Usage Viewer also displays peak usage statistics.

The graphs use the peak values that are recorded each day. For any day on which the engine is not used, they use a value of zero. They require a minimum of two days’ data to be generated. Otherwise, Capacity Usage Viewer displays an error message.

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To access Capacity Usage Viewer

In PCC Pervasive PSQL Explorer, right-click the engine you want to examine.

Its context menu opens.

Click Capacity Usage Viewer from the context menu.

Capacity Usage Viewer GUI

The following image shows the GUI. The table below the image describes the GUI objects. Click on an area of the image for which you want more information.

Figure 20 Capacity Usage Viewer User Interface


GUI Object	Description
Title Bar	Identifies the engine you selected.
Statistical Indicators	Displays meaningful statistics and enables you to select what you want to display in the graphs. See Statistical Indicators.
Time Designation	Displays the starting and ending dates of the period for the data displayed in the graphs.
Session Usage Graph	Displays, graphically, the number of sessions that occurred concurrently during the selected time period.
Data Usage Graph	Displays, graphically, the amount of data used during the selected time period.
Usage Level Bars	Enables you to determine how often your usage exceeds a selected level. When selected, they appear across each graph at a default level that is 90% of peak usage. The number at the left of each usage level bar identifies its level (amount of data or number of sessions). You can move the usage level bar to whatever level you need, either by using the spin boxes or by dragging with the cursor. The two usage level bars are independent of each other.
Zoom Instructions	Describes the general procedures for zooming in and out of a graph. For detailed procedures, see Zooming.
Export Button	Enables you to export the data to a .CSV file, if you find it useful to save the data for additional analysis. The Export button opens a Browse for Folder dialog, where you can select a location for data storage.

Figure 21 Statistical Indicators

GUI Object

Description

Period

Enables you to select the time period for the data you want the graphs to display. When the window opens, the graphs display, by default, the data from the period that was selected when the window was last closed. You can select a different time period:

You can also select a time period by zooming the graphs. When you zoom a graph, the Period drop-down menu displays Custom as the selected time period.

Peak Statistics Group Box

Contains fields that display statistics for maximum use of data and maximum number of concurrent sessions during the time period displayed in the graphs.

Peak Sessions

Displays the greatest number of concurrent sessions that occurred during the time period displayed in the Session Usage graph.

Peak Sessions Date

Displays the date on which the greatest number of concurrent sessions occurred. If that number of sessions occurred more on more than one day, the most recent date is displayed.

Peak Data (GB)

Displays the maximum amount of data, in gigabytes, used at one time during the time period displayed in the Data Usage graph.

Peak Data Date

Displays the date on which the maximum amount of data was used. If that amount of data was used on more than one day, the most recent date is displayed.

Show Usage Level Bars

Displays or hides usage level bars across the graphs, depending on whether it is checked or not.

Usage Statistics Group Box

Contains spin boxes for moving the usage level bars up and down and fields that display the statistics that result from moving the usage level bars.

Sessions

Sets the value at which to position the usage level bar in the Session Usage graph.

Days Exceeded

Displays the number of days on which the number of concurrent session in use was greater than the level at which the usage level bar is set.

Data (GB)

Sets the value at which to position the usage level bar in the Data Usage graph.

Days Exceeded

Displays the number of days on which the amount of data in use was greater than the level at which the usage level bar is set.

Zooming

If you need to view a particular time period besides the selections provided in the Period pull-down menu, you can select and zoom a segment of a graph. When you zoom one graph, the other zooms simultaneously. The two graphs are always set to the same period.

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To zoom a graph

Place the cursor at the start of the period you want to display.

With your left mouse button pressed down, drag the cursor to the end of the period you want to display. In the graph, a rectangular black outline appears around the selected part of the graph. As you move the cursor, the rectangle enlarges accordingly.

Release the mouse button. The graph is re-rendered to display the period you selected. The Period field displays the setting Custom.

Repeat the process to zoom further.

To zoom out, place the cursor anywhere in the graph and, with your left mouse button pressed down, drag the cursor from right to left. The graph returns to its original period, that is, the period it displayed when the window opened.