prestodb/presto · error · PrestoException

NOT_SUPPORTED

NOT_SUPPORTED

Error message

unsupported type: ${type}

What it means

RcFileEncoding.getEncoding maps a Presto/Hive type to its RCFile column encoder. If the type has no registered encoder (the switch over type signatures falls through), the library throws PrestoException(NOT_SUPPORTED) because RCFile RCBinary/Text encoding simply has no implementation for that type.

Source

Thrown at presto-rcfile/src/main/java/com/facebook/presto/rcfile/RcFileEncoding.java:127

        }
        String baseType = type.getTypeSignature().getBase();
        if (ARRAY.equals(baseType)) {
            ColumnEncoding elementType = getEncoding(type.getTypeParameters().get(0));
            return listEncoding(type, elementType);
        }
        if (MAP.equals(baseType)) {
            ColumnEncoding keyType = getEncoding(type.getTypeParameters().get(0));
            ColumnEncoding valueType = getEncoding(type.getTypeParameters().get(1));
            return mapEncoding(type, keyType, valueType);
        }
        if (ROW.equals(baseType)) {
            return structEncoding(
                    type,
                    type.getTypeParameters().stream()
                            .map(this::getEncoding)
                            .collect(toList()));
        }
        throw new PrestoException(NOT_SUPPORTED, "unsupported type: " + type);
    }
}

View on GitHub (pinned to 55bb57d202)

Solutions

1. Identify the unsupported type from the message and change the table column to a supported type (e.g. convert INTERVAL or custom types to VARCHAR/BIGINT)
2. Rewrite the table in ORC or Parquet format, which supports far more types
3. If the type should be supported, upgrade Presto to a newer version where RCFile type coverage was extended
4. Catch PrestoException with code NOT_SUPPORTED and fall back to a different connector/format

Example fix

// before
CREATE TABLE t (i interval day to second) WITH (format = 'RCFILE');
// after
CREATE TABLE t (i varchar) WITH (format = 'RCFILE'); -- or use ORC

Set<Signature> supported = ...; // from RcFileEncoding switch
if (!isSupportedRcFileType(columnType)) {
    throw new IllegalArgumentException("Column type not supported by RCFile: " + columnType);
}
try {
    encodingFactory.getEncoding(columnType);
} catch (PrestoException e) {
    if (e.getErrorCode() == StandardErrorCode.NOT_SUPPORTED.toErrorCode().getCode()) {
        // fall back to ORC or reject table
    }
}

boolean isSupportedRcFileType(Type type) {
    return type instanceof BigintType || type instanceof IntegerType || type instanceof SmallintType
        || type instanceof TinyintType || type instanceof DoubleType || type instanceof RealType
        || type instanceof BooleanType || type instanceof VarcharType || type instanceof VarbinaryType
        || type instanceof DateType || type instanceof TimestampType;
}

try { enc = getEncoding(type); } catch (PrestoException e) { if (NOT_SUPPORTED == e.getErrorCode().getName()) { enc = fallbackEncodingFor(type); } else { throw e; } }

When it happens

Trigger: Calling getEncoding (directly or via columnEncoding/elementType/keyType/valueType) with a type outside the supported set — e.g. exotic types like INTERVAL, UNKNOWN, custom parametric types, or nested types whose component types are unsupported (a MAP with an unsupported key type recurses into keyType and throws here).

Common situations: Tables created with Hive types Presto's RCFile reader doesn't implement; a schema change adding a new column type to an existing RCFile table; deeply nested types (array<map<...>>) where an inner type is unsupported.

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.

Related errors

• NOT_SUPPORTED
• NOT_SUPPORTED
• NOT_SUPPORTED
• NOT_SUPPORTED
• NOT_SUPPORTED

AI-assisted analysis of prestodb/presto@55bb57d202 (2026-09-04). Data as JSON: /api/errors/3099bd1944e2bf1f. Report an issue: GitHub.