advisor.Rule{Item:"DIS.001", Severity:"L1", Summary:"消除不必要的 DISTINCT 条件", Content:"太多DISTINCT条件是复杂的裹脚布式查询的症状。考虑将复杂查询分解成许多简单的查询,并减少DISTINCT条件的数量。如果主键列是列的结果集的一部分,则DISTINCT条件可能没有影响。", Case:"SELECT DISTINCT c.c_id,count(DISTINCT c.c_name),count(DISTINCT c.c_e),count(DISTINCT c.c_n),count(DISTINCT c.c_me),c.c_d FROM (select distinct id, name from B) as e WHERE e.country_id = c.country_id", Position:0, Func:func(*advisor.Query4Audit) advisor.Rule {...}}