diff --git a/app/models/ticket/overviews.rb b/app/models/ticket/overviews.rb
index 5c9048e27..ff7ffa366 100644
--- a/app/models/ticket/overviews.rb
+++ b/app/models/ticket/overviews.rb
@@ -19,11 +19,11 @@ returns
 
     # get customer overviews
     if data[:current_user].role?('Customer')
-      role = Role.find_by(name: 'Customer')
+      role_id = Role.lookup(name: 'Customer').id
       overviews = if data[:current_user].organization_id && data[:current_user].organization.shared
-                    Overview.where(role_id: role.id, active: true).order(:prio)
+                    Overview.where(role_id: role_id, active: true).order(:prio)
                   else
-                    Overview.where(role_id: role.id, organization_shared: false, active: true).order(:prio)
+                    Overview.where(role_id: role_id, organization_shared: false, active: true).order(:prio)
                   end
       overviews_list = []
       overviews.each { |overview|
@@ -36,8 +36,8 @@ returns
 
     # get agent overviews
     return if !data[:current_user].role?('Agent')
-    role = Role.find_by(name: 'Agent')
-    overviews = Overview.where(role_id: role.id, active: true).order(:prio)
+    role_id = Role.lookup(name: 'Agent').id
+    overviews = Overview.where(role_id: role_id, active: true).order(:prio)
     overviews_list = []
     overviews.each { |overview|
       user_ids = overview.user_ids
@@ -104,12 +104,13 @@ returns
                             .where(query_condition, *bind_condition)
                             .order(order_by)
                             .limit(500)
+                            .pluck(:id, :updated_at)
 
       tickets = []
       ticket_result.each { |ticket|
         ticket_item = {
-          id: ticket.id,
-          updated_at: ticket.updated_at,
+          id: ticket[0],
+          updated_at: ticket[1],
         }
         tickets.push ticket_item
       }
diff --git a/app/models/ticket/permission.rb b/app/models/ticket/permission.rb
index 06f192066..9b59f488a 100644
--- a/app/models/ticket/permission.rb
+++ b/app/models/ticket/permission.rb
@@ -14,7 +14,7 @@ returns
 
 =end
 
-  def permission (data)
+  def permission(data)
 
     # check customer
     if data[:current_user].permissions?('ticket.customer')
diff --git a/app/models/user.rb b/app/models/user.rb
index 7c847e837..732dbbc59 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -333,9 +333,9 @@ returns
 
   def permissions
     list = {}
-    Object.const_get('Permission').joins(:roles).where('roles.id IN (?)', role_ids).each { |permission|
-      next if permission.preferences[:selectable] == false
-      list[permission.name] = true
+    Object.const_get('Permission').select('permissions.name, permissions.preferences').joins(:roles).where('roles.id IN (?)', role_ids).pluck(:name, :preferences).each { |permission|
+      next if permission[1]['selectable'] == false
+      list[permission[0]] = true
     }
     list
   end
@@ -374,13 +374,13 @@ returns
       if local_key =~ /\.\*$/
         local_key.sub!('.*', '.%')
         permissions = Object.const_get('Permission').with_parents(local_key)
-        list = Object.const_get('Permission').joins(:roles).where('roles.id IN (?) AND (permissions.name IN (?) OR permissions.name LIKE ?)', role_ids, permissions, local_key)
+        list = Object.const_get('Permission').select('preferences').joins(:roles).where('roles.id IN (?) AND (permissions.name IN (?) OR permissions.name LIKE ?)', role_ids, permissions, local_key).pluck(:preferences)
       else
         permissions = Object.const_get('Permission').with_parents(local_key)
-        list = Object.const_get('Permission').joins(:roles).where('roles.id IN (?) AND permissions.name IN (?)', role_ids, permissions)
+        list = Object.const_get('Permission').select('preferences').joins(:roles).where('roles.id IN (?) AND permissions.name IN (?)', role_ids, permissions).pluck(:preferences)
       end
-      list.each { |permission|
-        next if permission.preferences[:selectable] == false
+      list.each { |preferences|
+        next if preferences[:selectable] == false
         Cache.write(key, true, expires_in: 20.seconds)
         return true
       }
@@ -419,8 +419,8 @@ returns
         permission_ids.push permission.id
       }
       next if permission_ids.empty?
-      Role.select('id').joins(:roles_permissions).where('permissions_roles.permission_id IN (?) AND roles.active = ?', permission_ids, true).uniq().each { |role|
-        role_ids.push role.id
+      Role.joins(:roles_permissions).where('permissions_roles.permission_id IN (?) AND roles.active = ?', permission_ids, true).uniq().pluck(:id).each { |role_id|
+        role_ids.push role_id
       }
       total_role_ids.push role_ids
     }