apache/seatunnel · error · IllegalArgumentException

Unsupported FloatingPoint precision:

Error message

Unsupported FloatingPoint precision: 

What it means

FloatingPointTypeWriter.writeToVector maps Arrow FloatingPoint precision to Float4Vector (SINGLE) or Float8Vector (DOUBLE). Arrow defines only HALF/SINGLE/DOUBLE; HALF is not handled, so a HALF precision field reaches the else branch and throws IllegalArgumentException. It means the writer cannot serialize the float value into a vector of that precision.

Solutions

1. Change the target column to SINGLE (float4) or DOUBLE (float8) precision, recreating the dataset if needed.
2. Cast half-float values to float in the upstream transform before the sink.
3. Upgrade the connector if Float16 support is added in a newer version.

Example fix

// before
new ArrowType.FloatingPoint(FloatingPointPrecision.HALF)
// after
new ArrowType.FloatingPoint(FloatingPointPrecision.SINGLE)

ArrowType t = field.getType(); if (t instanceof ArrowType.FloatingPoint && ((ArrowType.FloatingPoint) t).getPrecision() == FloatingPointPrecision.HALF) throw new IllegalArgumentException("HALF float not supported by lance sink");

try { writer.write(row); } catch (IllegalArgumentException e) { if (e.getMessage().startsWith("Unsupported FloatingPoint precision")) { /* recast column to SINGLE/DOUBLE */ } throw e; }

When it happens

Trigger: A field's ArrowType is FloatingPoint with precision HALF (Float16) and writeToVector is called for it.

Common situations: Dataset schema created externally with half-float columns (common in ML/embedding data stored in Lance) being written by this SeaTunnel connector, which lacks Float16 support.

Related errors

• List type should be handled via…
• Nested list writing not yet implemented
• COMMON-17
• Failed to close allocator
• List as map key is not supported

AI-assisted analysis of apache/seatunnel@cf67b549a7 (2026-09-10). Data as JSON: /api/errors/4ee498adb97a9e3f. Report an issue: GitHub.

Appendix: source

Thrown at seatunnel-connectors-v2/connector-lance/src/main/java/org/apache/seatunnel/connectors/seatunnel/lance/sink/writers/FloatingPointTypeWriter.java:45

import org.apache.arrow.vector.types.pojo.ArrowType;

/** Writer for FloatingPoint type. */
public class FloatingPointTypeWriter extends BaseTypeWriter {
    @Override
    public void writeToVector(
            FieldVector vector,
            ArrowType arrowType,
            Object value,
            int rowIndex,
            BufferAllocator allocator) {
        ArrowType.FloatingPoint fpType = (ArrowType.FloatingPoint) arrowType;
        Number numValue = (Number) value;
        if (fpType.getPrecision() == FloatingPointPrecision.SINGLE) {
            ((Float4Vector) vector).setSafe(rowIndex, numValue.floatValue());
        } else if (fpType.getPrecision() == FloatingPointPrecision.DOUBLE) {
            ((Float8Vector) vector).setSafe(rowIndex, numValue.doubleValue());
        } else {
            throw new IllegalArgumentException(
                    "Unsupported FloatingPoint precision: " + fpType.getPrecision());
        }
    }

    @Override
    public void writeToListWriter(
            UnionListWriter writer, ArrowType arrowType, Object value, BufferAllocator allocator) {
        ArrowType.FloatingPoint fpType = (ArrowType.FloatingPoint) arrowType;
        Number numValue = (Number) value;
        if (fpType.getPrecision() == FloatingPointPrecision.SINGLE) {
            writer.writeFloat4(numValue.floatValue());
        } else if (fpType.getPrecision() == FloatingPointPrecision.DOUBLE) {
            writer.writeFloat8(numValue.doubleValue());
        }
    }

    @Override
    public void writeToMapKey(

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