Regarding 'Tie::File flushing certain lines to disk and upon rereading them', I am using 'Deferred Writing' for tie. So any modification I make to tied array should be written to disk only when I untie the file. So line numbers should not change while reading this file contents. And while reading from this tiedArray it should give the modified contents & not the original contents.

I also suspect the problem is coming due to flushing of 'deferred write buffer' as I am writing a lot of data to @tieArray. But my confusion is that in that case the contents of file 'myFile' after 'untie' should also come wrongly.