连接表之前的投影对MySQL更有效吗？

Question

我有一个查询，在超过一分钟后将结果返回给我：

select distinct o.OMS_IDTOPO,e.TYPEQPTL,e.LIBUPR,
                o.OMS_SITEA,o.OMS_SITEB,
            siteA.Code_Postal as CPA, siteB.Code_Postal as CPB,
            siteA.Nom_court as NomA, siteB.Nom_court as NomB,
            siteA.Commune as ComA,siteB.Commune as ComB,
            siteA.Lat_GPS as latA,siteA.Long_GPS as longA,
            siteB.Lat_GPS as latB,siteB.Long_GPS as longB 
from occ_wdm_oms as o 
left join noeud_dico_traitement  as siteA on o.OMS_IDNOEUDA=siteA.Code_DICO
left join noeud_dico_traitement  as siteB on o.OMS_IDNOEUDB=siteB.Code_DICO
left join  occ_wdm_eqpt as e on o.OMS_IDTOPO=e.OMS_IDTOPO
where o.OMS_IDTOPO NOT LIKE '%.VP%'
and  siteA.Lat_GPS != 0 and siteA.Long_GPS != 0 
and  siteB.Lat_GPS != 0 and siteB.Long_GPS != 0;

但是，如果我做一个像

这样的投影

select distinct o.OMS_IDTOPO,e.TYPEQPTL,e.LIBUPR,
                o.OMS_SITEA,o.OMS_SITEB,
            siteA.Code_Postal as CPA, siteB.Code_Postal as CPB,
            siteA.Nom_court as NomA, siteB.Nom_court as NomB,
            siteA.Commune as ComA,siteB.Commune as ComB,
            siteA.Lat_GPS as latA,siteA.Long_GPS as longA,
            siteB.Lat_GPS as latB,siteB.Long_GPS as longB 
from occ_wdm_oms as o 
left join noeud_dico_traitement  as siteA on o.OMS_IDNOEUDA=siteA.Code_DICO
left join noeud_dico_traitement  as siteB on o.OMS_IDNOEUDB=siteB.Code_DICO

left join (select distinct LIBUPR,TYPEQPTL,OMS_IDTOPO from occ_wdm_eqpt) as e on o.OMS_IDTOPO=e.OMS_IDTOPO

where o.OMS_IDTOPO NOT LIKE '%.VP%'
and  siteA.Lat_GPS != 0 and siteA.Long_GPS != 0 
and  siteB.Lat_GPS != 0 and siteB.Long_GPS != 0;

只需10秒钟。

我发现了两个类似的问题：Which MySQL JOIN query is more efficient?和Optimizing join in vertica。

答案告诉我通常第一个版本效率更高。

我解释了两个查询，结果看起来像告诉我同样的事情。

Explain for first query

Explain for another query

我很困惑，因为实际上我通过投影查询会更快地得到结果，如果有什么我错过了吗？