prestodb/presto · error · PrestoException

FUNCTION_IMPLEMENTATION_ERROR

FUNCTION_IMPLEMENTATION_ERROR

Error message

Unexpected group enum type %s

What it means

Internal invariant failure (FUNCTION_IMPLEMENTATION_ERROR) in ArrayAggregationStateFactory.createGroupedState: the configured grouped-state mode enum has a value outside the known NEW/LEGACY set, so no grouped state class can be constructed. This reflects a configuration/build inconsistency, not user input.

Source

Thrown at presto-main-base/src/main/java/com/facebook/presto/operator/aggregation/arrayagg/ArrayAggregationStateFactory.java:56

        return new SingleArrayAggregationState(type);
    }

    @Override
    public Class<? extends ArrayAggregationState> getSingleStateClass()
    {
        return SingleArrayAggregationState.class;
    }

    @Override
    public ArrayAggregationState createGroupedState()
    {
        switch (mode) {
            case NEW:
                return new GroupArrayAggregationState(type);
            case LEGACY:
                return new LegacyArrayAggregationGroupState(type);
            default:
                throw new PrestoException(FUNCTION_IMPLEMENTATION_ERROR, format("Unexpected group enum type %s", mode));
        }
    }

    @Override
    public Class<? extends ArrayAggregationState> getGroupedStateClass()
    {
        switch (mode) {
            case NEW:
                return GroupArrayAggregationState.class;
            case LEGACY:
                return LegacyArrayAggregationGroupState.class;
            default:
                throw new PrestoException(FUNCTION_IMPLEMENTATION_ERROR, format("Unexpected group enum type %s", mode));
        }
    }
}

View on GitHub (pinned to 55bb57d202)

Solutions

1. Verify the array-agg grouped-state configuration/property uses a supported mode value
2. Use the default NEW mode unless legacy behavior is explicitly required
3. Report as a bug if a documented enum value triggers this path

When it happens

Trigger: Thrown at presto-main-base/src/main/java/com/facebook/presto/operator/aggregation/arrayagg/ArrayAggregationStateFactory.java:56 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/e224584f7cc9a093. Report an issue: GitHub.