Cannot search on a particular index

Model:

class TechRequest < ActiveRecord::Base
...
  define_index do
  ...
    indexes  :hot_request
    indexes :status_id, :as => :current_status_id
  ...
    has :hot_request , :as => :hot_request
    set_property :delta => true
  end

DB:

hot_request - tinyint(1)

When I execute the controller code-

@query_string = '(@hot_request 1)(@current_status_id 1 | 2 | 3)'
@tech_requests = TechRequest.search @query_string, :match_mode => :extended

the following error is thrown up:

ThinkingSphinx::SphinxError: index tech_request_core,tech_request_delta: query error: no field 'tech_hot_request' found in schema
        from D:/Current/TechAssistTest/vendor/plugins/thinking-sphinx/lib/thinking_sphinx/search.rb:392:in 'populate'
        from D:/Current/TechAssistTest/vendor/plugins/thinking-sphinx/lib/thinking_sphinx/search.rb:508:in 'call'
        from D:/Current/TechAssistTest/vendor/plugins/thinking-sphinx/lib/thinking_sphinx/search.rb:508:in 'retry_on_stale_index'
        from D:/Current/TechAssistTest/vendor/plugins/thinking-sphinx/lib/thinking_sphinx/search.rb:379:in 'populate'
        from D:/Current/TechAssistTest/vendor/plugins/thinking-sphinx/lib/thinking_sphinx/search.rb:167:in 'method_missing'
        from D:/ruby/lib/ruby/1.8/irb.rb:302开发者_开发百科:in 'output_value'
        from D:/ruby/lib/ruby/1.8/irb.rb:151:in 'eval_input'
        from D:/ruby/lib/ruby/1.8/irb.rb:263:in 'signal_status'
        from D:/ruby/lib/ruby/1.8/irb.rb:147:in 'eval_input'
        from D:/ruby/lib/ruby/1.8/irb.rb:146:in 'eval_input'
        from D:/ruby/lib/ruby/1.8/irb.rb:70:in 'start'
        from D:/ruby/lib/ruby/1.8/irb.rb:69:in 'catch'
        from D:/ruby/lib/ruby/1.8/irb.rb:69:in 'start'
        from D:/ruby/bin/irb:13

The search works fine when I use hot_request as an attribute. The search also works fine when I use @query_string = '(@current_status_id 1 | 2 | 3)'.

I've just run into similar looking problems - there are two possible reasons why this errors that I can see. First is that according to http://sphinxsearch.com/forum/view.html?id=2103 you can use an sql column as a field or an attribute but not both (without cloning it). The other, which had me baffled for a while, is that you may need to specify the type - so if hot_request is actually an integer, you probably need to have something like

indexes hot_request :as => hr, :type => :integer

or you get that cryptic error message

Hope this helps someone ...