<div>yea it`s interesting indeed.</div>
<div>but just to clear it up.. php is just used because i know php. the actual speed is in MySQL</div>
<div>the final script should be done in c/c++ with mysql and i expect that to be alot faster in total parsetime.</div>
<div>mysql won`t speed up much.. even likely to slow down more with all the checks that needs to be done.<br><br> </div>
<div><span class="gmail_quote">2007/4/12, Panu Matilainen <<a href="mailto:pmatilai@laiskiainen.org">pmatilai@laiskiainen.org</a>>:</span>
<blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">On Wed, 11 Apr 2007, Rahul Sundaram wrote:<br><br>> Mark wrote:<br>>> forgive me if i sound hard but:
<br>>> do you really need proof to see that the dependency checking is a highly<br>>> time consuming thing.<br>>> i just did a yum update.<br>>> i had a 100% cpu usage for a few minutes during the dep checking. that`s
<br>>> _TOO_ much for just a update. (oke.. this is a update of 148 packages but<br>>> still)<br>>><br>>> it just seems overkill for me.. specially now that i know that it can all<br>>> be done in well under a second in a logic way :P
<br>>><br>><br>> You _don't_ know that. What you are doing might be logical in a simplistic<br>> way but it just doesn't deal with a lot of real world cases. When you actual<br>> start dealing with all of the logic that is required to solve the
<br>> dependencies properly you would lose the speed advantage that you currently<br>> have.<br><br>Well, depsolving *can* be that fast, the proof can be found in apt-rpm<br>which takes just a few seconds (depends on the computer speed of course)
<br>to calculate something like fc5 -> fc6 upgrade with over thousand<br>packages. Apt does pay some penalty for abstracting packaging systems<br>(deb vs rpm) and for all the wacko pinning + other package priority<br>calculations, plain rpm depsolve in C would be quite a bit faster still.
<br><br>As for yum depsolve speed... the folks just rewrote the yum depsolver to<br>avoid having to download headers for depsolving, a no small feat.<br>Correctness needs to come first, speed is secondary (although important)
<br>issue. Just how fast it can be made with just python remains to be seen<br>(people are working on improving the speed all the time), but writing<br>mockup depsolvers in PHP isn't going to help that cause. Writing a
<br>depsolver in any language is of course an interesting self-education,<br>nothing wrong with that :)<br><br> - Panu -<br><br><br><br>--<br>fedora-devel-list mailing list<br><a href="mailto:fedora-devel-list@redhat.com">
fedora-devel-list@redhat.com</a><br><a href="https://www.redhat.com/mailman/listinfo/fedora-devel-list">https://www.redhat.com/mailman/listinfo/fedora-devel-list</a><br></blockquote></div><br>