Incorrect Count of Functions in PostgreSQL agent Despite Their Existence in the Database (4379740)

A PostgreSQL Foglight agent displays an incorrect number of functions in Databases dashboard Functions column.

Users may observe one of the following:

• No functions are returned, even though user-defined functions exist in the database.
• Some system functions appear in the results, which seems to contradict documentation stating that only user-defined functions are shown.

No Functions Returned

The pg_stat_user_functions view used by the PostgreSQL agent only displays statistics for user-defined functions that have been executed since the last statistics reset or server restart. If a function has not been called, it will not appear in this view.

System Functions Appear

While the view is intended to track user-defined functions, any function that is executed and not marked as internal-only may appear — including system functions — if:

• The function is explicitly called.
• The track_functions setting is set to all.

For example:

• shobj_description() from the pg_catalog schema may appear if it was called directly.
• pg_stat_statements() may appear if a wrapper function was created in the public schema or if the extension was installed there.

To Make User-Defined Functions Appear

• Execute the function manually using a SELECT statement, for example:
  SELECT public.my_function();  -- Replace with your actual function name and arguments
• Re-run the query:
  SELECT * FROM pg_stat_user_functions;
The function should now appear with its execution statistics. 

Check the Configuration

• Confirm that track_functions = all is set in postgresql.conf
• Note: This setting requires a PostgreSQL server restart to take effect. Reloading the config with SELECT pg_reload_conf(); is not sufficient.

Clarification on System Functions:

• • System functions may appear in pg_stat_user_functions if they are explicitly executed and tracked.
  • This behavior is expected when track_functions = all is enabled.