5.3.5.3 Large Cross Product Static Table Drivers

Static Table Drivers are generally used in a distributive fashion, and the Static Table Driver user interface is engineered for this typical use case. Some features of the user interface are limited for Static Table Drivers having large numbers of Key leaf values (or node values) in conjunction with large numbers of Target leaf values. For these cases, you must maintain your large Static Table Driver rules using Excel Export/Import functionality.

Limit on Large Cross Products

The Static Table Driver user interface is designed to allow you to specify coefficient values for any combination - or even for every combination - of your Key leaves and Target leaves. For example, a simple Static Table Driver having 50 Key Leaf values (in one Key Leaf dimension) and 100 Target Leaf values (in one Target Leaf dimension) could have as many as 5,000 "active" combinations (that is, combinations for which coefficients are defined). Typically, the number of defined combinations is a small fraction of the number of possible combinations.

The number of possible combinations is determined by the Cartesian product of the number of leaf values in each dimension in your Static Table Driver rule. For example, a Static Table Driver rule having 5,000 Key Leaf values (in one Key Leaf dimension) and 5,000 Target Leaf values (in one Target Leaf dimension) has a cross product of 25 million. The performance and response time of the Static Table Driver user interface can degrade with extremely large cross products. For this reason, the application applies a limit of 20 million on the size of the cross product. You may modify the default limit by manually updating SETUP_PARAMETERS_MASTER.STATIC_TABLEID_TEMP_TABLE_CROSS_JOIN_LIMIT. When you are working with a Static Table Driver whose cross product exceeds the cross-join limit, the Coefficients tab of the Static Table Driver user interface displays only the "defined" combinations, which are combinations where coefficients are previously established.

Managing Large Cross Product Static Table Drivers

To build a Static Table Driver that will have a very large cross product, follow the normal steps of building out your Key leaf (or node) values and your Target leaf values on the Static Table Driver Definition tab. If you start with a modest number of defined Key and Target leaves, the Coefficients tab operates normally, and you may save coefficients for any possible combination of Key and Target leaves that you have defined on the Definition tab. If you navigate to the Definition tab, add more Key leaves and Target leaves, and then return to the Coefficients tab, the Coefficients tab allows you to edit coefficients for any possible combination of your selected Key and Target leaves. This is applicable as long as you have not exceeded the cross-product limit. After you have added enough combinations on the Definition tab for the rule to exceed to cross-product limit, the Coefficients tab no longer shows the unmapped combinations. In this state, you can edit the coefficient values for any previously mapped combination, but you can no longer establish new combinations and coefficient values within the Coefficients tab.

Note:

Instead of starting the build process with a modest number of Key leaves and Target leaves, you might also begin by specifying a very large number of Key and Target leaf values. If you specify enough values in the Definition tab to exceed the cross product limit, then when you initially transition to the Coefficients tab it will appear blank. Regardless of whether your Static Table Driver rule begins as a small rule and evolves into a large cross product rule or your Static Table Driver rule was "large" at the time it was defined, the Coefficients tab only displays the "defined" combinations after you have exceeded the cross- product limit.

Editing Existing Coefficient Values

You can edit the coefficient value for any defined combination within the user interface. Alternatively, you can also export your data and edit coefficient values offline.

Adding New Combinations and Coefficients

To add new combinations and coefficients, perform the following steps:

1. Navigate to the Definition tab and add new Key & Target leaf values.
2. Navigate to the Coefficient tab and export your rule to a spreadsheet.
3. Add your new combinations and their coefficients to the spreadsheet.
4. Save and import the spreadsheet.

Removing Combinations and Coefficients

You can remove coefficients within the Coefficient tab by deleting the coefficient and saving the rule. After you have removed the coefficient for a combination of Key ' Target leaves, that combination is no longer updatable within the Coefficient tab. However, the combination remains defined (that is, you could still add a coefficient to this combination offline).

Navigate to the Definition tab to completely remove defined Key and Target leaf values, and remove the leaves that are no longer required.