Optimizing OR Queries in Rails and MySQL

According to MySQL doc, I must use union and temporary tables.

It seems I have to do something along the line of this:

http://www.ricroberts.com/articles/2007/09/25/mysql-temporary-tables-and-rails

There are cases where I use OR queries quite often. I am talking about
queries like this "where column_1 = 123 OR column_2 = 123". It seems
MySQL indices cannot properly optimize this.

Are there plugins or snippets out there that automagically hide the
complexity of using temporary tables for such queries?

According to MySQL doc, I must use union and temporary tables.

It seems I have to do something along the line of this:

http://www.ricroberts.com/articles/2007/09/25/mysql-temporary-tables-

There are cases where I use OR queries quite often. I am talking about
queries like this "where column_1 = 123 OR column_2 = 123". It seems
MySQL indices cannot properly optimize this.

I don't think that's quite true - on mysql5 it should be able to do an
index merge: http://dev.mysql.com/doc/refman/5.0/en/index-merge-optimization.html

Fred