exception: PG::Error: ERROR:  column "system_upload_id" does not exist
LINE 1: ...oad_id from post_uploads)) AND (id NOT IN (SELECT system_upl...
                                                             ^
: SELECT  "uploads".* FROM "uploads"  WHERE (created_at < '2014-06-06 12:01:08.398710') AND (id NOT IN (SELECT upload_id from post_uploads)) AND (id NOT IN (SELECT system_upload_id from post_uploads)) AND (id NOT IN (SELECT custom_upload_id from post_uploads)) AND (id NOT IN (SELECT gravatar_upload_id from post_uploads)) AND (url NOT IN ('/uploads/default/20/89859f6b42bcb187.jpg','/uploads/default/19/6cfb2a9f347c4bf9.png','/uploads/default/31/2012353b9ea7d7fe.png'))  ORDER BY "uploads"."id" ASC LIMIT 1000
context: {:current_db=>"default", :current_hostname=>"talk.openmrs.org"}
backtrace: /var/www/discourse/vendor/bundle/ruby/2.0.0/gems/rack-mini-profiler-0.9.1/lib/patches/sql_patches.rb:160:in `exec'
/var/www/discourse/vendor/bundle/ruby/2.0.0/gems/rack-mini-profiler-0.9.1/lib/patches/sql_patches.rb:160:in `async_exec'
/var/www/discourse/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/connection_adapters/postgresql_adapter.rb:815:in `block in exec_no_cache'
/var/www/discourse/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/connection_adapters/abstract_adapter.rb:373:in `block in log'
/var/www/discourse/vendor/bundle/ruby/2.0.0/gems/activesupport-4.1.1/lib/active_support/notifications/instrumenter.rb:20:in `instrument'
/var/www/discourse/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/connection_adapters/abstract_adapter.rb:367:in `log'
/var/www/discourse/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/connection_adapters/postgresql_adapter.rb:815:in `exec_no_cache'
/var/www/discourse/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/connection_adapters/postgresql/database_statements.rb:137:in `exec_query'
/var/www/discourse/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/connection_adapters/postgresql_adapter.rb:947:in `select'
/var/www/discourse/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/connection_adapters/abstract/database_statements.rb:31:in `select_all'
/var/www/discourse/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/connection_adapters/abstract/query_cache.rb:69:in `select_all'
/var/www/discourse/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/querying.rb:39:in `find_by_sql'
/var/www/discourse/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/relation.rb:603:in `exec_queries'
/var/www/discourse/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/relation.rb:487:in `load'
/var/www/discourse/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/relation.rb:231:in `to_a'
/var/www/discourse/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/relation/batches.rb:118:in `find_in_batches'
/var/www/discourse/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/relation/batches.rb:51:in `find_each'
/var/www/discourse/app/jobs/scheduled/clean_up_uploads.rb:19:in `execute'
/var/www/discourse/app/jobs/base.rb:131:in `block (2 levels) in perform'