afv-library/skills/debugging-apex-logs/references/common-issues.md

Common Debug Log Issues

SOQL in loop

Signals

• repeating SOQL_EXECUTE_BEGIN
• query appears inside repeated method path

Fix pattern

• query once outside the loop
• use Map<Id, SObject> or grouped collections

DML in loop

Signals

• repeated DML_BEGIN
• high DML statement count for small transactions

Fix pattern

• collect changes
• do one bulk DML operation

Non-selective query

Signals

• high rows scanned
• slow query timing
• table-scan indicators

Fix pattern

• add indexed filters
• reduce scope
• use query-plan guidance

CPU pressure

Signals

• CPU usage trending toward sync limit
• repeated expensive helper methods
• nested loops / repeated string work

Fix pattern

• reduce algorithmic complexity
• cache repeated work
• move heavy processing async where appropriate

Heap pressure

Signals

• large collection allocations
• heap usage approaching sync limit

Fix pattern

• use SOQL for-loops
• reduce in-memory object size
• clear collections when done

Null pointer / unhandled exceptions

Signals

• EXCEPTION_THROWN
• FATAL_ERROR
• clear stack trace with line numbers

Fix pattern

• guard null values
• make assumptions explicit
• improve result handling for empty query results