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David and Jonathan are having trouble with testing namespaced controllers using RSpec. They have two controllers, Admin::MyController and SuperUser::MyController, and the RSpec tests appear to be finding the wrong controller.
Their short-term solution is to put a manual require in the spec that was getting confused.
UPDATE – The issue turns out to be a naming conflict. The app has a model named SuperUser, and the existence of this model can cause class loading to be confused for SuperUser::* controllers. In Socialitis, our standard is to use plural names for controller namespace names, to prevent this sort of confusion.
Steve has learned that, in general, it’s a good idea to avoid using offsets when manipulating large quantities of data in MySQL. Luckily, some of MySQL’s quirks help with this:
- MySQL sorts indexes. The primary key is the main index that it sorts.
- Any select without an explicit order clause will pick an index, then return data in sorted order by that index. Again, usually you’ll see the primary key first.
You can take advantage of this behavior to paginate through a large dataset where the order doesn’t really matter. The following statements perform better than your typical LIMIT/OFFSET clause:
SELECT * FROM big_table WHERE id > 1 LIMIT 1000 SELECT * FROM big_table WHERE id > 1000 LIMIT 1000 SELECT * FROM big_table WHERE id > 2000 LIMIT 1000
acts_as_solr uses this technique for reindexing.
- Also, inserting a record in the middle of an id ‘hole’ is not a very good idea in MySQL, because the database then puts a great deal of work into reordering all of the later records.
Here’s a link to a related blog post: