Function compute_file_group_statistics 

pub fn compute_file_group_statistics(
    file_group: FileGroup,
    file_schema: SchemaRef,
    collect_stats: bool,
) -> Result<FileGroup>

Computes the summary statistics for a group of files(FileGroup level’s statistics).

This function combines statistics from all files in the file group to create summary statistics. It handles the following aspects:

• Merges row counts and byte sizes across files
• Computes column-level statistics like min/max values
• Maintains appropriate precision information (exact, inexact, absent)

Parameters

• file_group - The group of files to process
• file_schema - Schema of the files
• collect_stats - Whether to collect statistics (if false, returns original file group)

Returns

A new file group with summary statistics attached