Function decode_column_index 

pub fn decode_column_index(
    data: &[u8],
    column_type: Type,
) -> Result<ColumnIndexMetaData, ParquetError>

Decode a Thrift ColumnIndex from the provided bytes.

The passed in bytes contain a serialized Thrift OffsetIndex struct as read from a Parquet file. The column_type can be obtained via ColumnChunkMetaData::column_type.

Returns a ColumnIndexMetaData containing per-page statistics.

Example

// Open the Parquet file
let mut file = File::open("data.parquet")?;
let reader = SerializedFileReader::new(file.try_clone()?)?;
let metadata = reader.metadata();

// Select a row group and column to read
let row_group_idx = 0;
let column_idx = 0;

// Get the column chunk metadata
let row_group = metadata.row_group(row_group_idx);
let column_chunk = row_group.column(column_idx);

// Get the column index byte range from the column metadata
if let Some(range) = column_chunk.column_index_range() {
    // Get the column type for proper deserialization
    let column_type = column_chunk.column_type();

    // Read the column index bytes from the file
    let mut buffer = vec![0u8; (range.end - range.start) as usize];
    file.seek(std::io::SeekFrom::Start(range.start))?;
    file.read_exact(&mut buffer)?;

    // Decode the column index
    let column_index = decode_column_index(&buffer, column_type)?;

    // Access per-page statistics (example for INT32 column)
    use parquet::file::page_index::column_index::ColumnIndexMetaData;
    match column_index {
        ColumnIndexMetaData::INT32(index) => {
            for (i, (min, max)) in index.min_values().iter()
                .zip(index.max_values().iter())
                .enumerate() {
                println!("Page {}: min={}, max={}", i, min, max);
            }
        }
        _ => println!("Column is not INT32 type"),
    }
}