小编Art*_*rov的帖子

我有两个相当简单的查询。第一个查询

 UPDATE mp_physical SET periodic_number = '' WHERE periodic_number is NULL;

这是计划

 duration: 0.125 ms  plan:
    Query Text: UPDATE mp_physical  SET periodic_number = '' WHERE periodic_number is NULL;
    Update on mp_physical  (cost=0.42..7.34 rows=1 width=801)
      ->  Index Scan using "_I_periodic_number" on mp_physical  (cost=0.42..7.34 rows=1 width=801)
            Index Cond: (periodic_number IS NULL)

第二个：

 UPDATE observations_optical_temp SET designation = '' WHERE periodic_number is NULL;

它的计划是：

duration: 2817.375 ms  plan:
    Query Text: UPDATE observations_optical_temp SET periodic_number = '' WHERE periodic_number is NULL;
    Update on observations_optical_temp …