Computers and heat density

On 8/14/06, Don <THX1138 at dakotacom.net> wrote: Agreed. I ran into a Perl debugging situation at one company where the code to hit the database and aggregate thousands of e-mail addresses was written by a web developer and then handed off to a database developer when the first guy left. Essentially, the problem was that on a particular day, the code, which had been working, got swamped because it was (legitimately) being asked to handle 20 times the normal amount of recipients. At the bottom of everything, there was a loop with '$x .= $r[$n]' sort of a construct in it to build a list of names, and there was so much string copying going on in the loop that the Perl interpreter eventually barfed (after chewing on the list for 8 hours). My solution was to replace the inner loop with a '$x = $r[$a..$b]' construct - the modified program ran to completion in 20 minutes. The "real" problem was that the first guy didn't really understand the impact of his original construction on the underlying system, and "it worked" for a few thousand names. Didn't scale worth beans, though. -ethan