thinkharderdev commented on code in PR #2774:
URL: https://github.com/apache/arrow-rs/pull/2774#discussion_r979271132


##########
parquet/src/arrow/array_reader/builder.rs:
##########
@@ -26,40 +26,43 @@ use crate::arrow::array_reader::{
     ListArrayReader, MapArrayReader, NullArrayReader, PrimitiveArrayReader,
     RowGroupCollection, StructArrayReader,
 };
-use crate::arrow::schema::{convert_schema, ParquetField, ParquetFieldType};
+use crate::arrow::schema::{ParquetField, ParquetFieldType};
 use crate::arrow::ProjectionMask;
 use crate::basic::Type as PhysicalType;
 use crate::data_type::{
     BoolType, DoubleType, FloatType, Int32Type, Int64Type, Int96Type,
 };
-use crate::errors::Result;
+use crate::errors::{ParquetError, Result};
 use crate::schema::types::{ColumnDescriptor, ColumnPath, Type};
 
 /// Create array reader from parquet schema, projection mask, and parquet file 
reader.
 pub fn build_array_reader(
-    arrow_schema: SchemaRef,
-    mask: ProjectionMask,
+    field: Option<&ParquetField>,
+    mask: &ProjectionMask,
     row_groups: &dyn RowGroupCollection,
 ) -> Result<Box<dyn ArrayReader>> {
-    let field = convert_schema(&row_groups.schema(), mask, 
Some(arrow_schema.as_ref()))?;
+    let reader = field
+        .and_then(|field| build_reader(field, mask, row_groups).transpose())
+        .transpose()?
+        .unwrap_or_else(|| make_empty_array_reader(row_groups.num_rows()));

Review Comment:
   Not a comment on this PR per se, but I don't understand why we swallow the 
error here and return and empty array reader



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