I was trying to find a question that I'd commented on on math.stackexchange.com (This should be MUCH easier than it is!!).
I found the query frontend at http://data.stackexchange.com/stackoverflow/query/edit/....
select id,DisplayName from Users where len(DisplayName)=8 and DisplayName like 'user%' order by DisplayName
returns user4891 and user4895 one after the other, without user4894 in the middle. Here is a screencap of the relevant part of the results:
What is happening? Numerous other query attempts returned similar results, the query behaves correctly but does not find me.