apache/beam · error · UnsupportedOperationException

Unsupported type:

Error message

Unsupported type: 

What it means

TableSchema.parseDefaultExpression evaluates a column's DEFAULT/MATERIALIZED expression and converts the literal result to a Java value based on the column's TypeName. If the column type has no conversion case in this switch, it throws UnsupportedOperationException("Unsupported type: " + columnType), meaning defaults for that type are not implemented.

Solutions

1. Remove the DEFAULT expression from the unsupported column in the schema, or set the default client-side/in the table DDL instead.
2. Add a case for the needed TypeName in parseDefaultExpression and contribute/patch the connector.
3. Handle UnsupportedOperationException when calling parse() on schemas that may contain such columns and skip default materialization for them.

Example fix

// before
// schema: "tags Array(String) DEFAULT []" -> Unsupported type: ARRAY(Array...)
// after
// schema: "tags Array(String)" // no default expression

if (column.getDefaultExpression() != null &&
    Set.of("ARRAY","MAP","TUPLE","STRUCT","IPV4","IPV6","UUID","ENUM")
       .contains(column.getType().getTypeName().name())) {
  throw new IllegalStateException("default expressions unsupported for " + column.getType().getTypeName());
}

try {
  schema = TableSchema.parse(str);
} catch (IllegalArgumentException | UnsupportedOperationException e) {
  // strip DEFAULT expressions from unsupported columns and retry, or skip defaults
}

When it happens

Trigger: Parsing a schema whose column with a default expression has a TypeName not handled by the switch (e.g. ARRAY, MAP, STRUCT/TUPLE, or other complex types) — only numeric, string, bool, and decimal cases are implemented.

Common situations: Schemas containing DEFAULT expressions on composite types like Array(String) or Map(...), or newly added ClickHouse types that the Beam ClickHouse connector's default-expression support has not caught up with.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

• char type not supported yet…
• Converting BigQuery type
• Converting to Beam schema type is not supported
• DateTime64 precision must be in [0, 9], got
• Decimal precision must be in [1, 76], got

AI-assisted analysis of apache/beam@12126d8942 (2026-09-13). Data as JSON: /api/errors/5207add7129f6e89. Report an issue: GitHub.

Appendix: source

Thrown at sdks/java/io/clickhouse/src/main/java/org/apache/beam/sdk/io/clickhouse/TableSchema.java:451

        case ENUM16:
        case ENUM8:
        case FIXEDSTRING:
        case STRING:
          return value;
        case UINT8:
          return Short.valueOf(value);
        case UINT16:
          return Integer.valueOf(value);
        case UINT32:
          return Long.valueOf(value);
        case UINT64:
          return Long.valueOf(value);
        case BOOL:
          return Boolean.valueOf(value);
        case DECIMAL:
          return new BigDecimal(value);
        default:
          throw new UnsupportedOperationException("Unsupported type: " + columnType);
      }
    }

    abstract Builder toBuilder();

    public static Builder builder() {
      return new AutoValue_TableSchema_ColumnType.Builder();
    }

    @AutoValue.Builder
    abstract static class Builder {

      public abstract Builder typeName(TypeName typeName);

      public abstract Builder arrayElementType(ColumnType arrayElementType);

      public abstract Builder nullable(boolean nullable);

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