4 ms·
Interesting, every question in this quiz is about the concept of covering indexes, and figuring out if the query in question is covered by the suggested index o
by henrikschroder 13y ago
Interesting, every question in this quiz is about the concept of covering indexes, and figuring out if the query in question is covered by the suggested index or not.
I'm surprised people didn't score better on this, it's a very simple concept. :-/
- cwyers 13y agoThe author has a website and sells a book devoted to teaching people about SQL indexing, so that's where his focus is. I wonder what kind of a pool he got; given that he seems to have given it mostly to people reading his site, you'd think that it'd be people who know more about SQL indexing than the average. Most troubling to me was how people who chose the MySQL option did so much worse than pretty much every other database. (I took the MySQL option, even though I work on MS SQL these days, and got 4 out of 5.) I suppose for people who consider MySQL to be a toy RDBMS, that's less "troubling" than "confirming current perception."
- icedchai 13y agoI've interviewed many "senior developers" can't even JOIN two tables. The concept of a "covering index" might as well be brain surgery.
- jsmeaton 13y agoI agree. I scored 5 out of 5 (Oracle flavour), and didn't have to think too hard about any of the questions. The review article specifically mentions that he has no data about the kinds of people answering the test though. A lot of people just don't do raw SQL that often.