Alex Papadimoulis

Founder, The Daily WTF

Nov 2019

Classic WTF: Manager of the Data Dump

by in Feature Articles on
It's a holiday in the US, where we catalog the things we're thankful for. I'm thankful that developers collectively learned to understand how databases work, and didn't start releasing databases that stored flexible documents with no real schema and could just be used as a data dump. That would be terrible! This classic WTF illustrates that. Originally. --Remy

J.T. is not well liked amongst the developers at his organization. As a Database Administrator, it's J.T's job to make sure that database structures and queries maintain data integrity and do not put an unnecessarily load on the server. This often gets in the way of the developers, who prefer to think of the database as a giant dump site where data gets thrown and is rummaged through to be retrieved. Things like "indexes," "valid data," and "naming conventions" are merely obstacles put in place by J.T. to make their life harder.

Generally, the submission-review-rejection procedure happens once or twice with most of the developers. But one particular developer -- a newly hired ".NET Wizard" named Frank -- turns the procedure into a daily cycle that drags on for several weeks. Following is Frank's reply to the first in a chain of rejections on a project that Frank was leading up ...

Overlapping Complexity

by in CodeSOD on

After his boss left the company, Joel C was promoted to team lead. This meant that Joel was not only responsible for their rather large production codebase, but also for interviewing new potential team members. There are a ton of coding questions that one can ask in a technical interview, and Joel figured he should ask one that they actually solve in their application: given two unordered sets of timestamps, calculate how much overlap (if any) is between the two series.

If you think about it for a minute, it's really quite simple: first, find the minimum and maximum values for each set to get the start and end times (e.g. [01:08:01,01:09:55] and [01:04:11,01:09:42]). Then, subtract the later start time (01:08:01) from the earlier end time (01:09:42) to get the overlap (01:09:42 - 01:08:01 = 00:01:41). A non-positive result would indicate there's no overlap (such as 12:00:04 - 13:11:43), and in that case, it should probably just be zero. Or, in a single line of code: