When encountering the error 0Z002: Stacked Diagnostics Accessed Without Active Handler in PostgreSQL, it indicates an attempt to access diagnostic information when no exception has been raised. This error is unusual in typical application use and suggests a misconfiguration or misuse of exception handling in PL/pgSQL code or similar contexts. Here's an immediate action plan:
- Identify the Query or Code Block Triggering the Error:
- If the error occurs during the execution of a specific operation or query, try to pinpoint which action triggers it. This can often be deduced from application logs or by observing at what point the application encounters the issue.
- Review PL/pgSQL Functions or Triggers:
- If the error is related to a stored procedure, function, or trigger, review the PL/pgSQL code. Look for any
GET STACKED DIAGNOSTICS statements that might be executed outside an EXCEPTION block. The correct usage should be within an EXCEPTION block, like so: BEGIN
-- some operations
EXCEPTION WHEN others THEN
GET STACKED DIAGNSTICS variable = ITEM_NAME;
END;
- If you find such a statement outside of the proper context, move it inside an
EXCEPTION block or remove it if it's incorrectly placed.
- Check for Recent Changes:
- If the error started appearing after recent changes to the database (e.g., new functions, triggers, or updates to existing ones), review those changes for any improperly used diagnostic commands or exception handling structures.
- Execute Diagnostic Queries (If Applicable):
- While this specific error does not directly point to a problem solvable by running diagnostic queries, understanding the context in which it occurs can help. If possible, run the problematic code manually in a controlled environment (e.g., psql terminal, PgAdmin) and observe the behavior for additional clues.
- Inspect Application Logs:
- Review your application logs closely around the time the error occurs for any additional information that might indicate what operation or query is causing the issue.
- Consult Documentation or Community:
- If the steps above don't clarify the issue, consider searching for the error code
0Z002 in the PostgreSQL documentation or seeking advice from the PostgreSQL community forums or Stack Overflow, including the specific context in which the error occurs.
Remember, direct interaction with the database for diagnosis should be done cautiously, especially on production systems, to avoid unintentional disruptions or data loss.
