我當前的查詢是這個樣子:如何優化查詢
SELECT distinct pg.id,pg.email,pg.theme,op.PaymentMode,od.DeliveryMode,uv1.value AS FirstName, uv2.value AS LastName, uv3.value AS Mobile, uv4.value AS City, uv5.value AS State, uv6.value AS Address
FROM userdb.user u,userdb.paymentgatewaytracker pg,
oms.deliverymode od,oms.paymentmode op,
userdb.uservar uv1
JOIN userdb.uservar uv2 ON uv1.user_id = uv2.user_id
AND uv2.name = 'billingLastName'
LEFT JOIN userdb.uservar uv3 ON uv1.user_id = uv3.user_id
AND uv3.name = 'billingMobile'
JOIN userdb.uservar uv4 ON uv1.user_id = uv4.user_id
AND uv4.name = 'billingCity'
JOIN userdb.uservar uv5 ON uv1.user_id = uv5.user_id
AND uv5.name = 'billingState'
JOIN userdb.uservar uv6 ON uv1.user_id = uv6.user_id
AND uv6.name = 'billingAddress'
where uv1.name = 'billingFirstName'
AND u.id = uv1.user_id
AND u.email=pg.email
and op.PaymentModeId=pg.paymethod
and od.DeliveryModeId=pg.deliveryOption
ORDER BY pg.id
這是給我正確的結果,而我檢查我的本地主機。但我想在我的瀏覽器中顯示。而我正在嘗試這樣做時,它顯示致命錯誤:超過30秒的最大執行時間。但對於小型查詢,我正在瀏覽器中獲取結果。任何人都可以優化我上面給出的查詢。
您是否索引了所有適當的列? – 2011-04-18 09:13:02
請顯示你的解釋結果,tkx – Neo 2011-04-18 09:16:19