the implicit flush and/or lock release

I think this is the most important part. If you work with Windows (or cross-platform), having a file open for reading means that no one (including the same process) is allowed to rename or delete that file.
Probably seldom necessary, but makes e.g. PDF::API2::Simple failing one of ist tests on Windows...

In reply to Re^4: Identifying unmatched data in a database by soonix
in thread Identifying unmatched data in a database by ardibehest

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