2 files changed, 5 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/column.rb b/activerecord/lib/active_record/connection_adapters/column.rb
index 187eefb9e4..38efebeaf3 100644
--- a/activerecord/lib/active_record/connection_adapters/column.rb
+++ b/activerecord/lib/active_record/connection_adapters/column.rb
@@ -72,6 +72,8 @@ module ActiveRecord
       end
 
       # Casts a Ruby value to something appropriate for writing to the database.
+      # Numeric columns will typecast boolean and string to appropriate numeric
+      # values.
       def type_cast_for_write(value)
         return value unless number?
 
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/column.rb b/activerecord/lib/active_record/connection_adapters/postgresql/column.rb
index 2cbcd5fd50..1d22b56964 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/column.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/column.rb
@@ -98,6 +98,9 @@ module ActiveRecord
         end
       end
 
+      # Casts a Ruby value to something appropriate for writing to PostgreSQL.
+      # see ActiveRecord::ConnectionAdapters::Class#type_cast_for_write
+      # see ActiveRecord::ConnectionAdapters::PostgreSQLAdapter::OID::Type
       def type_cast_for_write(value)
         if @oid_type.respond_to?(:type_cast_for_write)
           @oid_type.type_cast_for_write(value)