Beefy Boxes and Bandwidth Generously Provided by pair Networks
Pathologically Eclectic Rubbish Lister

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??
If you need to modify a flat-file, and the size is such that it can't be slurped into memory (and a 1GB file probably can be ...), it's best to process the file one record at a time writing the modified records to another file. Then, swap the file-names around. If you slurp into memory, run a performance monitor to see if the virtual-memory subsystem starts thrashing, because VM swapping activity is a serious source of "invisible" disk I/O. If you process a record at a time, memory won't be an issue but data movement (a gigabyte is read and written) will be. But a one-gigabyte file should be processed sequentially in seconds, not 30 minutes.

In reply to Re: Need help to fine tune perl script to make it faster( currently taking more than 30 minutes) by Anonymous Monk
in thread Need help to fine tune perl script to make it faster( currently taking more than 30 minutes) by anujajoseph

Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":

  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?

    What's my password?
    Create A New User
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others scrutinizing the Monastery: (5)
    As of 2015-11-26 00:20 GMT
    Find Nodes?
      Voting Booth?

      What would be the most significant thing to happen if a rope (or wire) tied the Earth and the Moon together?

      Results (693 votes), past polls