EXPLAIN EXTENDED受影响的行数太多

Question

我的查询如下

SELECT COUNT(*) AS count 
FROM shop.CarInfo A 
LEFT JOIN shop.RegisterInfo B 
  ON A.CarID = B.RegisterInfoID 
LEFT JOIN shop.seller C 
  ON B.RegisterInfoID = C.CarID 
LEFT JOIN shop.CarSeller D 
  ON C.CarSellerID = D.PersonID 
LEFT JOIN shop.Licences E 
  ON B.RegisterInfoID = E.CarID 
LEFT JOIN shop.CarLicences F 
  ON E.CarLicenceID = F.CarLicenceID 
LEFT JOIN shop.CarsLocation G 
  ON A.location = G.CarLocationID 
LEFT JOIN shop.AnnounceStatement H 
  ON B.RegisterInfoID = H.CarID 
LEFT JOIN shop.Announcer I 
  ON H.AnnouncerID = I.AnnouncerID 
WHERE B.title LIKE '%Mercedes%' OR D.name LIKE '%Mercedes%' OR F.Licences LIKE  '%Mercedes%' OR B.RegNo LIKE '%Mercedes%' OR I.name LIKE '%Mercedes%'

不幸的是，这个查询需要很多回复！使用EXPLAIN EXTENDED，我得到了这个：

http://i59.tinypic.com/bj9udh.png [由于我还无法将图片上传到StackOverflow，我已经上传到tinypic]

据我所知，除了第一行外，一切都很好。考虑到我已经创建了合适的索引，为什么这么多行呢？