sql server---sql语句优化

xg3396

select distinct * from  (select b.branchcode,c.name,b.AgentCode,b.AgentName,  a.AlarmYM,a.AlarmBatchNo,a.ContNo,a.RiskCode,  a.StartVisitDate,   (select codename from ldcode where codetype='PreviewType' and a.AlarmIndexType=code ) as PreviewType, a.VisitResult,a.TreatResult,   (select Codename from ldcode  where  CodeType='instype' and a.TreatResult  = Code) as instype,a.TreatViews ,a.AlarmIndexType    from LACheckVisit a left outer join LAAgentInfo b on a.AgentCode=b.AgentCode  left outer join LABranchGroupInfo c on a.branchcode=c.AgentGroup    where 1=1   and exists (select 1 from lacompanyinfo where b.BranchCode=branchcode  and citycomcode='340400'  )  and a.AlarmYM='200810'  and a.AlarmBatchNo='1'  ) as result
执行该语句的时候，消耗cpu75%，哪位大哥帮忙分析一下，有优化的余地没？ 谢谢

xg3396

小弟 在线等待，谢谢  十万火急