Re: performace question...

Vince Laurent wrote:

> Quick question: Are full table scans bad for performance? I am
> guessing yes. I ran this script:
>
> set serverout on size 1000000
> set verify off
>
> col object_name form a30
>
> PROMPT Column flag in x$bh table is set to value 0x80000, when
> PROMPT block was read by a sequential scan.
>
> spool bufferts.lst
>
> SELECT o.object_name,o.object_type,o.owner
> FROM dba_objects o,x$bh x
> WHERE x.obj=o.object_id
> AND o.object_type='TABLE'
> AND standard.bitand(x.flag,524288)>0
> AND o.owner<>'SYS';
>
> spool off
>
> and the result on one of our DB was 5600! Since Sunday's backup! How
> can I tell the vendor that thier appliction, um, er... works harder
> than it needs to?
>
> Thanks
>
> --------------------------------------
> Come race with us!
> www.mgpmrc.org

There is nothing inherently wrong with a full table scan.

There are times when they are bad and there are times when they are the most optimal solution.

It seems to me you have insufficient information from which to formulate a conclusion.

-- 
Daniel Morgan
http://www.outreach.washington.edu/ext/certificates/oad/oad_crs.asp
http://www.outreach.washington.edu/ext/certificates/aoa/aoa_crs.asp
damorgan_at_x.washington.edu
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