Once perl has used some system memory for something, you'll be damm lucky if you get it back for other processes to use until perl exits. undef'ing a variable will return the memory used by that variable to perl, so it won't need to eat any more memory the next time it needs some.

This is one of the reasons why eating a whole file into memory is a bad thing, even if you throw it away soon after doing so.

If avoiding memory bloat is important, then you'll need to design an algorithm which doesn't use much in memory storage. Working on small chunks of data and saving the results to a file, then at the end of your program taking the saved results and putting them together into your final answer. Also consider using DB_File, although remember that disk access is much slower then RAM access.


In reply to Re: forced garbage collection by quidity
in thread forced garbage collection by Anonymous Monk

Title:
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, details, 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, summary, 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.