juliey 发表于 2008-04-25 02:19

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.

liaosnet 发表于 2008-04-25 09:09

update statistics for <tabname>

czw1413_cn 发表于 2008-04-29 11:41

ivhb 发表于 2008-04-29 18:44

原帖由 juliey 于 2008-4-25 02:19 发表 http://bbs.chinaunix.net/images/common/back.gif
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
....
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