prestodb/presto · error · UnsupportedOperationException

Unsupported type for 'bucket':

Error message

Unsupported type for 'bucket': 

What it means

PartitionTransforms.getColumnTransform implements the bucket transform only for supported key types (integers, long, date/time types, varchar, etc.); a type outside the supported set reaching the bucket branch raises this NOT_SUPPORTED error naming the offending type.

Source

Thrown at presto-iceberg/src/main/java/com/facebook/presto/iceberg/PartitionTransforms.java:227

                        block -> bucketDate(block, count),
                        (block, position) -> bucketValueDate(block, position, count));
            }
            if (type.equals(TIME)) {
                return new ColumnTransform(transform, INTEGER,
                        block -> bucketTime(block, count),
                        (block, position) -> bucketValueTime(block, position, count));
            }
            if (type instanceof VarcharType) {
                return new ColumnTransform(transform, INTEGER,
                        block -> bucketVarchar(block, count),
                        (block, position) -> bucketValueVarchar(block, position, count));
            }
            if (type.equals(VARBINARY)) {
                return new ColumnTransform(transform, INTEGER,
                        block -> bucketVarbinary(block, count),
                        (block, position) -> bucketValueVarbinary(block, position, count));
            }
            throw new UnsupportedOperationException("Unsupported type for 'bucket': " + field);
        }

        matcher = TRUNCATE_PATTERN.matcher(transform);
        if (matcher.matches()) {
            int width = parseInt(matcher.group(1));
            if (type.equals(INTEGER)) {
                return new ColumnTransform(transform, INTEGER,
                        block -> truncateInteger(block, width),
                        (block, position) -> {
                            if (block.isNull(position)) {
                                return null;
                            }
                            return truncateInteger(block, position, width);
                        });
            }
            if (type.equals(BIGINT)) {
                return new ColumnTransform(transform, BIGINT,
                        block -> truncateBigint(block, width),

View on GitHub (pinned to 55bb57d202)

Solutions

1. Apply bucket(n, col) only to supported column types
2. Change the partition column type or use a different transform for unsupported types (e.g. varbinary, complex types)

When it happens

Trigger: Thrown at presto-iceberg/src/main/java/com/facebook/presto/iceberg/PartitionTransforms.java:227 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/b5a0d8e6103c98cf. Report an issue: GitHub.