Can we use threads in such a way that, multiple threads will be acting on the million record file so that the time is reduced to few minutes. ?

Probably not, since all the threads will be hitting a bottleneck of trying to read the same file at the same time. The limiting factor is how fast your hard drive is. See How do you parallelize STDIN for large file processing? and Is Using Threads Slower Than Not Using Threads? for examples.

There may be some improvements gained if you could use a program like split to break your huge file into smaller chunks, and place them on separate hard drives, then let your parallel processes work on them.

I'm not really a human, but I play one on earth.
Old Perl Programmer Haiku ................... flash japh

In reply to Re: how to split huge file reading into multiple threads by zentara
in thread how to split huge file reading into multiple threads by sagarika

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