Function analyze_record_batches 

pub fn analyze_record_batches<'a, I>(batches: I) -> ColumnStatistics
where
    I: IntoIterator<Item = &'a RecordBatch>,

Compute column statistics from an iterator of RecordBatches.

The result’s row_count is the sum across batches. min_value and max_value are taken across the union; null_count is the sum; distinct_count is the union of distinct values observed across all batches, up to EXACT_NDV_CAP.