Chinaunix

标题: EXPLAIN question [打印本页]

作者: juliey 时间: 2008-04-25 02:19
标题: EXPLAIN question
I created a table and index also created. But when I query by the index column, the EXPLAIN output as "SEQUENTIAL SCAN".

create unique index non_disc_idx1
on yk_non_disclosure
(ds_rin);

Please see the attached Screen shot.

Thanks.

Explain.JPG (44.71 KB, 下载次数: 19)

作者: liaosnet 时间: 2008-04-25 09:09
update statistics for <tabname>

作者: czw1413_cn 时间: 2008-04-29 11:41
提示: 作者被禁止或删除内容自动屏蔽

作者: ivhb 时间: 2008-04-29 18:44

原帖由 juliey 于 2008-4-25 02:19 发表
I created a table and index also created. But when I query by the index column, the EXPLAIN output as "SEQUENTIAL SCAN".

create unique index non_disc_idx1
on yk_non_disclosure
(ds_rin);
...

there are many ways to resolve this problem：
1，set OPTCOMPIND = 0
2，select {+ index(tabname) } from table tabname ....
3，update statistics
....

欢迎光临 Chinaunix (http://bbs.chinaunix.net/)