如何提高这条语句的性能
UPDATE FactLogin_201305 a,
Leads_2012 b
SET a.theCount = b.factCount,
a.theRoi = b.roi > 0
WHERE
a.allotStep = b.allotStep
AND a.salesType = b.salesType
AND a.cityOrder = b.cityOrder
AND a.salary = b.salary
AND a.gender = b.gender
AND a.education = b.education
AND a.ageStep = b.ageStep
AND a.gzt10 = b.gzt10;MySQL性能优化update
UPDATE FactLogin_201305 a,
Leads_2012 b
SET a.theCount = b.factCount,
a.theRoi = b.roi > 0
WHERE
a.allotStep = b.allotStep
AND a.salesType = b.salesType
AND a.cityOrder = b.cityOrder
AND a.salary = b.salary
AND a.gender = b.gender
AND a.education = b.education
AND a.ageStep = b.ageStep
AND a.gzt10 = b.gzt10;MySQL性能优化update
即WHERE 中的字段
allotStep,salesType,cityOrder,salary,gender,education,ageStep,gzt10
a.theRoi = b.roi > 0这是什么意思