Governor Limits in Apex
Introduction
Apex runs on a multi-tenant platform, meaning multiple organizations (tenants) share the same computing resources. To make sure no single code execution takes up all the resources and affects others, Salesforce enforces Governor Limits. These are runtime limits that every Apex execution must follow — such as limits on SOQL queries, DML operations, CPU time, and heap size.
If your code exceeds these limits, it throws a runtime exception, and the transaction fails.
Real-Life Analogy
Think of Salesforce as a public library with limited seating. To ensure fairness, there’s a time limit for how long each person can use a seat (just like a CPU time limit in Apex), and you can borrow only a certain number of books (similar to SOQL or DML limits).
If someone tries to break the rule and take 50 books at once, the librarian (Salesforce Governor) stops them immediately — the same way Apex Governor Limits prevent misuse of platform resources.
Common Apex Governor Limits
| Limit Type | Value (per transaction) |
|---|---|
| SOQL Queries | 100 queries |
| Records Retrieved via SOQL | 50,000 records |
| DML Statements | 150 statements |
| Records Processed via DML | 10,000 records |
| CPU Time | 10,000 ms (synchronous) |
| Heap Size | 6 MB (synchronous) |
If you need to process more records than the limit (e.g. >10,000), you should use Batch Apex.
1: Track SOQL Usage
List<Account> accList = [SELECT Name FROM Account LIMIT 10];
System.debug(‘SOQL Queries Used: ‘ + Limits.getQueries());
Output:
SOQL Queries Used: 1
Code Explanation:
• We queried Account once.
• Limits.getQueries() tells us how many SOQL queries have been used in this transaction.
2: Track DML Usage
List<Contact> contactList = new List<Contact>();
for (Integer i = 0; i < 3; i++) {
contactList.add(new Contact(FirstName=’Test’, LastName=’User’ + i));
}
insert contactList;
System.debug(‘DML Statements Used: ‘ + Limits.getDmlStatements());
Output:
DML Statements Used : 1
Code Explanation :
• We created and inserted 3 contacts using a single insert statement (bulk insert).
• Only 1 DML statement was used, keeping us within limits.
Best Practices to Stay Within Limits
• Bulkify your code: Avoid DML or SOQL inside for loops.
• Use Collections: Insert/update records in bulk.
• Query only required fields: Don’t use SELECT
• Use Limits methods to monitor usage (Limits.getQueries(), Limits.getDmlStatements() etc).
Tasks For Practice
Task 1: Count SOQL Queries Used
Run two SOQL queries and print the total queries used using Limits.getQueries().
Task 2: Check DML Statements
Insert 5 Lead records in one DML operation and print the number of DML statements used with Limits.getDmlStatements().
Task 3: Avoid DML in Loops
Write a loop that creates 10 Contact records, but insert them after the loop using a collection (List).
Check how many DML statements were used.
Task 4: Track CPU Time Usage
Write code that performs a long loop operation and use:
System.debug(‘CPU Time Used: ‘ + Limits.getCpuTime());
to see how much CPU time was consumed.
