def deleted_ids
      sql = <<-DR.squish
        SELECT object_id
        FROM rails_redshift_replicator_deleted_ids
        WHERE source_table = '#{replicable.source_table}'
      DR
      ActiveRecord::Base.connection.execute(sql).map{ |r| r['object_id'] }
    end
def deleted_ids
      sql = <<-DR.squish
        SELECT object_id
        FROM rails_redshift_replicator_deleted_ids
        WHERE source_table = '#{replicable.source_table}'
      DR
      ActiveRecord::Base.connection.execute(sql).map{ |r| r['object_id'] }
    end
Retrives ids of objects enqueued for deletion for the replication source table
 @example
 deleted_ids #=> "1,2,3,4,5"
 @return [String] list of ids enqueued to delete on target