select
b.NO as agent_code,
'Y' as is_pol
from basic_info b,status s where b.no = s.no and s.pol_sts = 'A'
and b.NO2<>b.NO1
这个sql我在表basic_info 建了索引index_basic_info(no,NO2,NO1)但是这个索引却没有用上?
这两个表(basic_info ,status )的数据均在100万条左右,是什么影响了索引不起作用,难道是<>这个操作?thanks!!!大家!!!
b.NO as agent_code,
'Y' as is_pol
from basic_info b,status s where b.no = s.no and s.pol_sts = 'A'
and b.NO2<>b.NO1
这个sql我在表basic_info 建了索引index_basic_info(no,NO2,NO1)但是这个索引却没有用上?
这两个表(basic_info ,status )的数据均在100万条左右,是什么影响了索引不起作用,难道是<>这个操作?thanks!!!大家!!!
已经建了!!我想知道这个<>是否影响索引的使用?
怎么用not exists??