我mysql升級到5.7之后開啟了BNL，使得一條陳述句變慢了。
EXPLAIN
SELECT o.id, t.exhibition_id, e.title, e.endingtime
FROM orderinfo o
INNER JOIN ticketinfo t ON o.ticket_id = t.id
INNER JOIN exhibition e ON e.id = t.exhibition_id
WHERE e.etype = 1
1 SIMPLE t ALL PRIMARY 109 100
1 SIMPLE e eq_ref PRIMARY PRIMARY 8 art.t.exhibition_id 1 10 Using where
1 SIMPLE o ALL 69515 10 Using where; Using join buffer (Block Nested Loop)
而關閉的話是
1 SIMPLE o ALL 73300
1 SIMPLE t eq_ref PRIMARY PRIMARY 8 art.o.ticket_id 1
1 SIMPLE e eq_ref PRIMARY PRIMARY 8 art.t.exhibition_id 1 Using where
請問一下可不可以指定一條陳述句執行時關閉BNL或者又其它優化方案
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標籤：MySQL
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