案例加入|查询优化

Question

我需要一些帮助来验证这个查询，

它在预览模式下运行，但是当我导入报告时，报告失败

select su4.USER_VALUE as CODICE_SKOFF,
      CASE WHEN (su1r.USER_ID = 'A' AND su4.USER_VALUE = '9') THEN 'TestA'
           WHEN (su1r.USER_ID = 'B' AND su4.USER_VALUE = '10') THEN 'TestB'
           WHEN (su1r.USER_ID = 'C' AND su4.USER_VALUE = '11') THEN 'TestC'
           WHEN (su1r.USER_ID = 'D' AND su4.USER_VALUE = '12') THEN 'TestD' 
           ELSE 'None'
      END

我认为这是因为CASE，它会使报告变慢并收到失败的消息

FROM之后我有几个left outer join

提前致谢