for (ColumnChunkMetaData column : block.getColumns()) {
int fieldId = fileSchema.aliasToId(column.getPath().toDotString());
increment(columnSizes, fieldId, column.getTotalSize());
increment(valueCounts, fieldId, column.getValueCount());
missingStats.add(fieldId);
} else if (!stats.isEmpty()) {
increment(nullValueCounts, fieldId, stats.getNumNulls());
updateMin(lowerBounds, fieldId,
fromParquetPrimitive(field.type(), stats.genericGetMin()));
updateMax(upperBounds, fieldId,
fromParquetPrimitive(field.type(), stats.genericGetMax()));
toBufferMap(fileSchema, lowerBounds), toBufferMap(fileSchema, upperBounds));