presto-tpcds/src/main/java/io/prestosql/plugin/tpcds/TpcdsMetadata.java/TpcdsMetadata/getPrestoType
class TpcdsMetadata:    public static Type getPrestoType(ColumnType tpcdsType)
    {
        switch (tpcdsType.getBase()) {
            case IDENTIFIER:
                return BigintType.BIGINT;
            case INTEGER:
                return IntegerType.INTEGER;
            case DATE:
                return DateType.DATE;
            case DECIMAL:
                return createDecimalType(tpcdsType.getPrecision().get(), tpcdsType.getScale().get());
            case CHAR:
                return createCharType(tpcdsType.getPrecision().get());
            case VARCHAR:
                return createVarcharType(tpcdsType.getPrecision().get());
            case TIME:
                return TimeType.TIME;
        }
        throw new IllegalArgumentException("Unsupported TPC-DS type " + tpcdsType);
    }