Separate parquet -> arrow conversion logic (apache#1655)

Don't treat embedded arrow schema as authoritative (apache#1663)

Fix projection of nested parquet files (apache#1652) (apache#1654)

Fix schema inference for repeated fields (apache#1681)

Support reading alternative list representations from parquet (apache#1680)

Consistent handling of unsupported arrow types in parquet (apache#1666)

arrow/src/datatypes/datatype.rs

@@ -181,6 +181,16 @@ pub enum IntervalUnit {
     MonthDayNano,
 }
 
+impl IntervalUnit {
+    pub fn get_byte_width(&self) -> usize {
+        match self {
+            IntervalUnit::YearMonth => 4,
+            IntervalUnit::DayTime => 8,
+            IntervalUnit::MonthDayNano => 16,
+        }
+    }
+}
+
 // Sparse or Dense union layouts
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
 pub enum UnionMode {