prestodb/presto · error · PrestoException

NOT_SUPPORTED

NOT_SUPPORTED

Error message

e.getMessage()

What it means

Error from element_at when looking up a key in a single-map block: the underlying seek/hash probe threw (typically a DuplicateMapKeyException from an inconsistent map block, or an invocation of the key equality/hash operator that failed), and the original exception's message is carried through on the INVALID_FUNCTION_ARGUMENT error.

Source

Thrown at presto-main-base/src/main/java/com/facebook/presto/operator/scalar/MapElementAtFunction.java:137

        return new BuiltInScalarFunctionImplementation(
                true,
                ImmutableList.of(
                        valueTypeArgumentProperty(RETURN_NULL_ON_NULL),
                        valueTypeArgumentProperty(RETURN_NULL_ON_NULL)),
                methodHandle);
    }

    @UsedByGeneratedCode
    public static Object elementAt(MethodHandle keyNativeHashCode, MethodHandle keyBlockNativeEquals, MethodHandle keyBlockHashCode, Type valueType, Block map, boolean key)
    {
        SingleMapBlock mapBlock = (SingleMapBlock) map;
        int valuePosition;
        try {
            valuePosition = mapBlock.seekKeyExact(key, keyNativeHashCode, keyBlockNativeEquals, keyBlockHashCode);
        }
        catch (NotSupportedException e) {
            throw new PrestoException(NOT_SUPPORTED, e.getMessage(), e);
        }

        if (valuePosition == -1) {
            return null;
        }
        return readNativeValue(valueType, mapBlock, valuePosition);
    }

    @UsedByGeneratedCode
    public static Object elementAt(MethodHandle keyNativeHashCode, MethodHandle keyBlockNativeEquals, MethodHandle keyBlockHashCode, Type valueType, Block map, long key)
    {
        SingleMapBlock mapBlock = (SingleMapBlock) map;
        int valuePosition;
        try {
            valuePosition = mapBlock.seekKeyExact(key, keyNativeHashCode, keyBlockNativeEquals, keyBlockHashCode);
        }
        catch (NotSupportedException e) {
            throw new PrestoException(NOT_SUPPORTED, e.getMessage(), e);

View on GitHub (pinned to 55bb57d202)

Solutions

1. Check that the map argument was built without duplicate keys
2. Verify the map's key type supports equality (e.g. not a key type with unimplemented operators)
3. Use try(element_at(m, k)) to tolerate occasional failures while investigating

When it happens

Trigger: Thrown at presto-main-base/src/main/java/com/facebook/presto/operator/scalar/MapElementAtFunction.java:137 when the library encounters an invalid state.

Common situations: See trigger scenarios.

Understand the failure class

Background: Presto NOT_SUPPORTED error: what "not supported" means and how to fix it — this error's family across 3 libraries.

AI-assisted analysis of prestodb/presto@55bb57d202 (2026-09-04). Data as JSON: /api/errors/2ed73e5b7f64b9ee. Report an issue: GitHub.