AR#column_names doesn't get all columns

on some tables I have the error "column doesn't exist", but they do.

I found the error in AR/base ... see diff:

diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index b2e058d..f132f7c 100644
--- a/activerecord/lib/active_record/base.rb +++ b/activerecord/lib/active_record/base.rb @@ -701,7 +701,8 @@ module ActiveRecord #:nodoc:

   # Returns an array of column names as strings.
   def column_names

•  @column_names = columns.map { |column| column.name }
  

•  # @column_names ||= columns.map { |column| column.name }
  

  end

after that all columsn would be fetched,
I think it is a performance issue,
but I haven't another solution this time