I have discovered a potential bug in activerecord-jdbc-adapter while working with db2. I am using paginate gem to paginate my sql results. My query is like this: self.paginate(:all,:page => 1,:per_page => 30,:order=> "name"], :conditions => [" country_id in (select distinct country_id from country) and group_id = 10 )"]) I had this query working fine when I was using ibm_db gem with my rails application. After I have to converted to jruby and start using activerecord-jdbc-adapter, the above statement fails because the query generated from this is incorrect. I further investigated it to find the root cause, and think found the problem. This will work fine if I remove the sub query from this statement i.e removing (select distinct country_id from country) will fix the issue. Problem seems to be in method replace_limit_offset of activerecord-jdbc-adapter-1.2.0\lib\arjdbc\db2\adapter.rb file. In this method, it replaces 'select' with this 'SELECT B.* FROM (SELECT A.*, row_number() over () AS internal$rownum FROM (SELECT' to introduce paging. While this is correct, but because I have two selects in my query (because of a subquery), both selects get replaced by this replace string, thus making the query invalid. Only first 'select' word in the string should have been replaced. Following code does this replacement: sql.gsub!(/SELECT/i, 'SELECT B.* FROM (SELECT A.*, row_number() over () AS internal$rownum FROM (SELECT') sql << ") A ) B WHERE B.internal$rownum > #{offset} AND B.internal$rownum <= #{limit + offset}" Am I right? Isn't it a bug? Has anyone else experienced the same issue? I am using the 1.2.0 version of the activerecord-jdbc-adapter gem.