The expression "xxx" uses a Field from an island table. Improper use of island fields may lead to performance problems. The field(s) are: "yyy"

Guide

Examine the performance of any chart using a data island expression. If a data island field it used with other dimensions, a temporary table of all possible combinations must be generated during calculation. To avoid this temp table generation, consider one of the following alternatives.

•For a single value island field, such as a currency selection, replace the field reference with a $() expression. The $() expression is calculated only one.

          - Sum(Sales) / $(=Only(CurrencyRate))

 

•Another good option is to replace the field reference with a variable calculation.

- Create a variable:  Set vCurrencyRate = =Only(CurrencyRate);  // Note the extra "="

- Use the variable in the expression: Sum(Sales) / $(vCurrencyRate)