Error
Error Code:
39P01
PostgreSQL Error 39P01: Trigger Protocol Violated
Description
This error indicates that a user-defined trigger function failed to adhere to the expected protocol when invoked by PostgreSQL. It typically occurs when the function returns an unexpected value, attempts a disallowed operation, or interacts incorrectly with the database during its execution, leading to an external routine invocation exception.
Error Message
trigger protocol violated
Known Causes
4 known causesIncorrect Trigger Function Return
The trigger function returned a value (e.g., wrong data type, structure) that does not conform to PostgreSQL's expected trigger protocol for triggers.
Invalid Row Manipulation
The trigger function attempted to modify row data or database state in a manner not permitted by the trigger's definition or execution phase.
Forbidden Operations in Trigger
The trigger function executed an operation (e.g., DDL statements, transaction control) that is explicitly forbidden within a PostgreSQL trigger's context.
External Language Interface Mismatch
For triggers written in external languages (like C, Python), the interface between PostgreSQL and the external function was not correctly implemented or called.
Solutions
Coming SoonDetailed step-by-step solutions for this error are being prepared. In the meantime, try these general troubleshooting tips:
General Troubleshooting Tips
- Check the error message carefully for specific details
- Review recent changes that might have caused the error
- Search for the exact error code in the official documentation
- Check log files for additional context
- Try restarting the application or service