Apex Performance Best Practices

This article is based on the PMD documentation article. See the original article on the PMD site: PMD: performance best practices.

Below are the generally accepted best practices. 

AvoidDmlStatementsInLoops #

Avoid DML statements inside loops to avoid hitting the DML governor limit. Instead, try to batch up the data into a list and invoke your DML once on that list of data outside the loop.

This rule is defined by the following Java class: 

net.sourceforge.pmd.lang.apex.rule.performance.AvoidDmlStatementsInLoopsRule

Example #

public class Something { public void foo() { for (Integer i = 0; i < 151; i++) { Account account; // … insert account; } } }

Properties #

AvoidSoqlInLoops #

New objects created within loops should be checked to see if they can created outside them and reused.

This rule is defined by the following Java class: 

net.sourceforge.pmd.lang.apex.rule.performance.AvoidSoqlInLoopsRule

Example #

public class Something { public static void main( String as[] ) { for (Integer i = 0; i < 10; i++) { List<Account> accounts = [SELECT Id FROM Account]; } } }

Properties #

AvoidSoslInLoops #

Sosl calls within loops can cause governor limit exceptions.

This rule is defined by the following Java class: 

net.sourceforge.pmd.lang.apex.rule.performance.AvoidSoslInLoopsRule

Example #

public class Something { public static void main( String as[] ) { for (Integer i = 0; i < 10; i++) { List<List<SObject>> searchList = [FIND ‘map*’ IN ALL FIELDS RETURNING Account (Id, Name), Contact, Opportunity, Lead]; } } }

Properties #