Re: simulating a select returning a million rows?

From: BChase <>
Date: Sat, 13 Jun 2009 07:52:09 -0400
Message-ID: <>

One way I read was that could also alter the statistics temporarily to trick the optimizer into thinking there were a million rows in a table that does not. It alters the explain plain accordingly and can alter performance as well.

On Sat, 13 Jun 2009 11:59:25 +0200, Robert Klemme <> wrote:

>On 07.06.2009 02:03, wrote:
>> Peter Nilsson <> wrote:
>>> Malcolm Dew-Jones wrote:
>>>> select rownum from dual connect by rownum <= 1000000
>>> More common is...
>>> select level from dual connect by level <= 1000000
>> Both of these are working perfectly for me... thanks to
>> both of you!
>But keep in mind that if you are investigating execution plans the mere
>fact that you do not query a real table might dramatically change the
>plan in question probably making the exercise useless.
>Kind regards
> robert
Received on Sat Jun 13 2009 - 06:52:09 CDT

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