Consider the order of terms in compound expressions
As a performance best practice, Guidewire recommends
that you carefully consider the order of comparisons in compound expressions
that use the and and or
operators. Runtime evaluation
of compound expressions that use and
proceed from left to right until a condition fails. Runtime evaluation
of compound expressions that use or proceed from left to right until a condition succeeds. The order
in which you place individual conditions can improve or degrade evaluation
performance of compound expressions.
With and expressions, place terms likely to fail earlier
Whenever you use the and operator, place the condition
that is most likely to fail or the least performance intensive earliest
in the compound expression. Use the following formula to help you determine
which condition to place first, based on the condition with the lowest
value.
(100 - failurePercentage) * (performanceCost)For example, you have a condition that you expect to fail 99% of the time, with an estimated performance cost of 10,000 per evaluation. You have another condition that you expect to fail only 1% of the time, with an estimated performance cost of 100 per evaluation. According to the formula, place the second condition earliest because it has the lowest score.
(100 - 99) * 10,000 = 10,000
(100 - 1) * 100 = 9,999You rarely have accurate figures for the failure percentages or performance costs of specific condition. Use the formula to develop an educated guess about which condition to place earliest. In general, give preference to less performance intensive condition. If the performance costs are roughly equal, give preference to condition with a higher percentage of likely failures.
With or expressions, place terms likely to pass earlier
When you use the or operator, place the condition
that is most likely to succeed earliest in compound expressions.