Story time: I once worked part time with a company, and their DBA was doing a project to look up all the IP addresses that had been logged into one of their database tables. For every address he was running a bash script to do the reverse lookup.

This was going to take a few days to run, largely because it was forking 10-20 times for every IP address, most of the lookups themselves were fairly quick (though some weren't). I explained to him that forks are fairly expensive operations, and every line in his shell script was 1+ forks.

I thought this would be an easy win, I picked up a multi-threaded DNS lookup tool and showed him that it could look up a thousand addresses in < a second. "Oh, so I can just replace the "nslookup" with this other program in my script?"

I explained that he would need to make a file with all the IP addresses he needed to look up, I'd run the program on a server at our data center (to not clog the office T1), and then I'd give him back a file containing "address,name".

"Oh... So I'd have to correlate each address to a name myself? I can't do that, I need to run this script." In my head I said "You're the DBA, how can you NOT correlate this data?"