Counts not always visible

Automatically calculate distributions - on¶

The Automatically calculate distributions option controls the extent to which bandings are updated each time the request is changed. This option can be found in Tools...Options...Selection...Selector Variables:

With the Automatically calculate distributions box checked, the banding will update fully each time the request is changed - for example, when changing the banding type or the number of bands. Note that there may be a slight delay before this update happens. If a further change is made to the request while calculation is in progress, then the previous request is cancelled.

Automatically calculate distributions - off¶

With the "Automatically calculate distributions" unchecked, the banding will update as far as is possible without having to process all the records. The following factors affect the degree to which the banding can be updated:

• All bandings that are created are cached (stored) and so can be retrieved without processing the data if the same banding is requested again
• Bandings for system variables are cached permanently, so will be available from one session to the next.
• Bandings for virtual variables and any banding based on a base selection are only stored while the banding tool is active, and so have to be regenerated each time a new tool is launched.

Avoiding processing¶

• If a banding cannot be retrieved from the cache, then the banding will be generated as far as is possible without the need to process the database.
• The boundary points for Equal Ranges and Geometric Ranges can be generate without processing the database, provided that the start and end points are known. In this case empty ranges are displayed as it is not possible to calculate the counts without processing the database.
• Quantile and User Defined Ranges cannot be calculated without the need to process the database and so not even the boundary points will be generated.

Examples¶

Banding retrieved fully from cache, enabling band boundaries and counts to be displayed. The Update button is disabled since the displayed banding is fully calculated.

Banding boundaries can be calculated for Equal Ranges, since the start and end points are known. Counts cannot be generated without processing the data, and so empty bands are shown. The Update button can be used to process the data and display the counts.

Quantile Ranges cannot be generated without processing the data and so no bands can be displayed. The Update button must be used to process the data, generating both the boundary points and the counts.