Oracle FAQ Your Portal to the Oracle Knowledge Grid
HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US
 

Home -> Community -> Mailing Lists -> Oracle-L -> Re: CURSOR_SHARING=SIMILAR + ODBC May Cause Problems

Re: CURSOR_SHARING=SIMILAR + ODBC May Cause Problems

From: rjamya <rjamya_at_gmail.com>
Date: Tue, 2 Aug 2005 14:36:38 -0400
Message-ID: <9177895d050802113629be4b83@mail.gmail.com>


what happens if you changed cs=force?

Raj

On 8/2/05, Post, Ethan <Ethan.Post_at_ps.net> wrote:
>
> Just wanted to share a situation I encountered last week at a site. User
> were complaining about performance in some conversion/testing environments.
> I noted that the conversion scripts were hard parsing 4000/minute on a 2 cpu
> box. I changed QUERY_REWRITE and CURSOR_SHARING to SIMILAR. Parsing dropped
> to low number but script writer called to complain about slowdown.
> Investigation showed that the hard parsing SQL looked like...
> select foo from table where ID=123456789;
> After parameter changes SQL looked like....
> select foo from table where substr(ID,:bind,:bind)=:bind;
> so basically after the change the index in ID was not used because of
> function but hard parse made SQL look great except and it used index.
> This was an ODBC application using pass-through to submit SQL to Oracle.
> Not sure of others have seen this sort of thing but would be happy to
> learn more.
>

-- 
------------------------------
select standard_disclaimer from company_requirements where category = 
'MANDATORY';

--
http://www.freelists.org/webpage/oracle-l
Received on Tue Aug 02 2005 - 13:40:09 CDT

Original text of this message

HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US