Has-Many.md

 > Finally my database won't have those pointless join tables. This is one of my most-wanted features.
 
-Has many connected through an array. PostgreSQL allows us to use arrays, Rails also allows us to use arrays, but why we have never been able to use them on associations. Well, honestly it was a bit hard to develop this feature, but the magic that it can do worth it. The idea is simple, one table stores all the ids and the other one says that `has many` records on that table because its records ids exist in the column of the array. Like: `Tag has many Videos connected through an array`. [PostgreSQL Docs](https://www.postgresql.org/docs/9.6/arrays.html)
+Has many connected through an array. PostgreSQL allows us to use arrays, Rails also allows us to use arrays, but why we have never been able to use them on associations. Well, honestly it was a bit hard to develop this feature, but the magic that it can do worth it.
+
+The idea is simple, one table stores all the ids and the other one says that `has many` records on that table because its records ids exist in the column of the array. Like: `Tag has many Videos connected through an array`. [PostgreSQL Docs](https://www.postgresql.org/docs/9.6/arrays.html)
 
 # How it works
 
@@ -33,4 +35,6 @@ end
 
 All the original features from the `has_many` association are available, preloading inclusive. You can check the methods on the [Associations Docs](https://api.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html) from Rails.
 
+**One important notice** is that polymorphic is not allowed for array-like associations, because the tuples can be guaranteed every time.
+
 There's no extra or additional provided method, only some for metaprogramming if necessary.
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