其中rownum = 1查询在Oracle中花费的时间 [英] where rownum=1 query taking time in Oracle

问题描述

我正在尝试执行

select * from tableName where rownum=1

这个查询基本上是要获取表的列名.表中有超过一百万条记录.当我把上面的条件放在上面时，它花了很多时间来获取第一行.第一行.

This query is basically to fetch the column names of the table.There are more than million records in the table.When I put the above condition its taking so much time to fetch the first row.Is there any alternate to get the first row.

推荐答案

尝试一下:

select * from tableName where rownum<=1

有一些奇怪的ROWNUM错误，有时稍微更改一下查询即可解决.我以前见过这种情况，但是我无法重现.

There are some weird ROWNUM bugs, sometimes changing the query very slightly will fix it. I've seen this happen before, but I can't reproduce it.

以下是有关类似问题的一些讨论: http://jonathanlewis.wordpress.com /2008/03/09/cursor_sharing/和 http ://forums.oracle.com/forums/thread.jspa?threadID = 946740&tstart = 1

Here are some discussions of similar issues: http://jonathanlewis.wordpress.com/2008/03/09/cursor_sharing/ and http://forums.oracle.com/forums/thread.jspa?threadID=946740&tstart=1

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