prestodb/presto · error · PrestoException

GENERIC_USER_ERROR

GENERIC_USER_ERROR

Error message

Cannot create function in built-in function namespace: %s

What it means

Error from the built-in function namespace manager's createFunction: an attempt was made to register a user-defined function in the built-in function namespace, which is read-only and reserved for functions shipped with Presto.

Source

Thrown at presto-main-base/src/main/java/com/facebook/presto/metadata/BuiltInTypeAndFunctionNamespaceManager.java:1077

    {
        for (SqlFunction function : functions) {
            for (SqlFunction existingFunction : this.functions.list()) {
                checkArgument(!function.getSignature().equals(existingFunction.getSignature()), "Function already registered: %s", function.getSignature());
            }
        }
        this.functions = new FunctionMap(this.functions, functions);
    }

    @Override
    public void setBlockEncodingSerde(BlockEncodingSerde blockEncodingSerde)
    {
        // Do not need to do anything here since BlockEncodingSerde is passed in constructor
    }

    @Override
    public void createFunction(SqlInvokedFunction function, boolean replace)
    {
        throw new PrestoException(GENERIC_USER_ERROR, format("Cannot create function in built-in function namespace: %s", function.getSignature().getName()));
    }

    @Override
    public void alterFunction(QualifiedObjectName functionName, Optional<List<TypeSignature>> parameterTypes, AlterRoutineCharacteristics alterRoutineCharacteristics)
    {
        throw new PrestoException(GENERIC_USER_ERROR, format("Cannot alter function in built-in function namespace: %s", functionName));
    }

    @Override
    public void dropFunction(QualifiedObjectName functionName, Optional<List<TypeSignature>> parameterTypes, boolean exists)
    {
        throw new PrestoException(GENERIC_USER_ERROR, format("Cannot drop function in built-in function namespace: %s", functionName));
    }

    public String getName()
    {
        return ID;
    }

View on GitHub (pinned to 55bb57d202)

Solutions

1. Create the function in a regular function namespace (a catalog/schema with function support)
2. Use a catalog configured with a UDF-capable function namespace manager
3. Use built-in functions or a connector-provided function instead of registering into the built-in namespace

When it happens

Trigger: Thrown at presto-main-base/src/main/java/com/facebook/presto/metadata/BuiltInTypeAndFunctionNamespaceManager.java:1077 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of prestodb/presto@55bb57d202 (2026-09-04). Data as JSON: /api/errors/5913aaeda5677eaf. Report an issue: GitHub.