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Home -> Community -> Mailing Lists -> Oracle-L -> Re: CURSOR_SHARING=SIMILAR + ODBC May Cause Problems
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-lReceived on Tue Aug 02 2005 - 13:40:09 CDT
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