gistfile1.txt

Given the following domain and scenario:

Topic has_many votes

A rails noob that has a massive dataset but little understanding into ActiveRecord query methods 
and little SQL knowledge.

Using elegant and idiomatic Ruby, what is a good solution for returning all topics sorted by the 
number of votes they have. Because of the SQL knowledge gap, you should avoid having to use SQL directly.

Pixeltrix

One issue I still have with this is that it's using the block to do the sorting. If you have 5 million topics and hundreds of votes each, surely you'd want the ordering to be done in the DB? I know then most people would say then you should optimize your query to use raw SQL but I feel that there is something missing that abstracts that and should belong in ActiveRecord::QueryMethods or somewhere.

If you have 5 million topics and hundreds of votes each, surely you'd want the ordering to be done in the DB?

But if you do have 5 million rows any kind of SQL ordering sucks as well. In those circumstances I'd probably look at using a full-blown search engine.