5,889
社区成员
发帖
与我相关
我的任务
分享DB2语句优化……
为什么我将下面的语句
(tax_date < current timestamp or hydraulic_date < current timestamp or inside_date < current timestamp);
修改为
(tax_date < current timestamp and year(tax_date) = year(current timestamp) or hydraulic_date < current timestamp and year(hydraulic_date ) = year(current timestamp) or inside_date < current timestamp and year(inside_date ) = year(current timestamp));
后，耗时增加了n倍？？请高手指点下！！
(tax_date < current timestamp or hydraulic_date < current timestamp or inside_date < current timestamp);
修改为
(tax_date < current timestamp and year(tax_date) = year(current timestamp) or hydraulic_date < current timestamp and year(hydraulic_date ) = year(current timestamp) or inside_date < current timestamp and year(inside_date ) = year(current timestamp));
后，耗时增加了n倍？？请高手指点下！！
...全文
请发表友善的回复…
发表回复
y_cl68 2007-08-09
- 打赏
- 举报
用函数year的话,索引会不起作用,做全表扫描
yangxiao_jiang 2007-08-08
- 打赏
- 举报
看看执行计划，那里耗时比较多
