Predicate push-down into parquet broken for Date32 columns

[yordan-pavlov]

Describe the bug
Earlier this week I found that predicate push-down into parquet for Date32 columns was broken in PR #426

I found that this was caused by missing branches in impl TryFrom<&DataType> for ScalarValue here https://github.com/apache/arrow-datafusion/blob/master/datafusion/src/scalar.rs#L924
which is used in get_min_max_values here https://github.com/apache/arrow-datafusion/blob/master/datafusion/src/physical_plan/parquet.rs#L508

I also found that adding the following lines into the try_from method resolves the issue:

DataType::Date32 => ScalarValue::Date32(None),
DataType::Date64 => ScalarValue::Date64(None),

To Reproduce

• filter Date32 column in a parquet data source
• the statistics column(s) generated for the filtered Date32 columns will be all null

Expected behavior
Statistics column(s) generated for Date32 columns from a parquet data source should not be all null

Additional context
n/a

@alamb

[alamb]

I can fix this @yordan-pavlov if you are not already doing do

[yordan-pavlov]

yes please @alamb , it would be great if you could; I have been working on more improvements for the parquet arrow reader so my local repo isn't very clean.

[alamb]

I will do so @yordan-pavlov