User Defined Collection (UDC) Wizard - History Model Custom Configuration

Time Pyramid tab

The purpose of the time pyramid tab is to give an optimized storage and performance and rapid access to the data of interest. The logic of this model is based on the premise that the closer the data is to the present, the more granular (i.e. measured in finer time units) you want it to be. Conversely, the further it is from the present, the less refined the desired time unit of measurement, illustrated as follows:

Placing the cursor focus on a Resolution line lets you change its value and (in the sliding window box below) that of the Keep For storage period. Any changes initiated will be immediately reflected in the Est. Server Space and Required Disk Space values.

Reset to enables resetting of the entire configuration to the selected model.

Collection Settings tab

Specify in this tab's SQL collection settings:

• The quantity of top dimension occurrences and occurrence combinations. The overall tradeoff is between the number (depth) of collected occurrences and impact on space. StealthCollect data is, in fact, stored in a number of aggregations. The value for items setting has a greatest impact on top level dimension comprehensiveness (and therefore accuracy). The item combinations setting more directly affects second and third level dimension drilldowns.

• Select the check box Remove literals in SQL to replace every literal encountered in SQL statements with a bind variable. This option is useful if the application generates dynamic SQL with embedded literal values and you want to aggregate the activity for these similar statements. This option is not selected by default.

• Select the Ignore statements if you want the collection to ignore statements whose activity was less than the Active Time (in seconds) that you specify here.

Use the Wait Events and Locks settings to:

• Enable/disable detailed wait events and locks collection.

• Define the threshold (as a percentage of the statement's entire active time) for the wait events and locks to exclude a statement from inclusion.

Disk Space Allocation tab

For advanced users:

• Use this option to manually override the system-determined UDC disk space requirement by specifying an alternative disk allocation. Your files will be permanently relocated to the new directory.

Note: Manually decreasing this disk allocation might cause a loss of data.

• Override the suggested default Data directory. The collection data files will be placed in the specified directory. Use this option if the default directory does not have sufficient free space.