It really isn't any more complex, it's just that DBI and mysql wrap most of that up for you. Any synchronized solution will have to take some kind of mutex, read and write the counter, then release the mutex, which is all my code does. If you were to use strace or gdb to step through the code involved for both cases (including the mysql server), you'd find that SysV is much simpler; it's just that you have to do more of the coding yourself, because it's not as widely used.

As far as memory tables, I had an error in my benchmark, I was running it with no rows in the table, so no updates were happening at all. I have corrected it in the original post, and also tried a MySQL memory table; SysV is about 4.7 times faster than a memory table. I also added a benchmark using mmap and an atomic add, which is much, much faster than any of the other solutions.

And as to the amount of work MySQL and SysV are doing behind the scenes, I don't see how it matters much unless the OP needs every update written immediately to disk. Otherwise MySQL is just doing extra work that the OP doesn't need.


--
sgifford's Web page

In reply to Re^5: Multiple write locking for BerkeleyDB by sgifford
in thread Multiple write locking for BerkeleyDB by dino

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.