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Re: all_synonyms: performance issues

From: Charles Schultz <sacrophyte_at_gmail.com>
Date: Wed, 23 Aug 2006 10:49:29 -0500
Message-ID: <7b8774110608230849mfa9961j50c03c2edf3321df@mail.gmail.com>


We are experimenting with cursor_sharing - it is a double-edge sword. Lots of new bugs quickly came to the surface. But that is OT. =) I kinda figured it was an internal query, but where do I find more information on it?

On 8/23/06, Powell, Mark D <mark.powell_at_eds.com> wrote:
>
> Perhaps it is the internal query where Oracle checks to see who the table
> belongs to in order to parse the query and check security. The presence of
> :"SYS_B_1" type names leads me to believe you have cursor_sharing set to
> similar. We have not had good luck when we tried to use that setting.
>
> -- Mark D Powell --
>
>
> ------------------------------
> *From:* oracle-l-bounce_at_freelists.org [mailto:
> oracle-l-bounce_at_freelists.org] *On Behalf Of *Charles Schultz
> *Sent:* Wednesday, August 23, 2006 11:21 AM
> *To:* oracle-l
> *Subject:* all_synonyms: performance issues
>
> Good day, list,
>
> In light of Metalink note *377037.1* (*Selects Against ALL_SYNONYMS
> Perform Badly on 10g Release 10.2*), we have been tracking down why we
> have so many calls to all_synonyms in the first place. We see a lot of these
> types of queries occuring:
> SELECT table_name, table_owner FROM all_synonyms WHERE owner = :"SYS_B_0"
> AND synonym_name = :"SYS_B_1"
>
> Where does this come from? When I queried v$sql, I could not find any
> parent cursors ( where parent.child_address = child.address and lower(
> child.sql_text) like '%all_synonyms%'). We are also unable to find
> explicit calls from the application, so we are operating under the
> assumption that Oracle does this as part of a recursive call. A 10046 trace
> will show this query and a preceding query (ie, select * from some_table),
> but I do not quite understand how they are related.
>
> Any help much appreciated,
>
> --
> Charles Schultz
>
>

-- 
Charles Schultz

--
http://www.freelists.org/webpage/oracle-l
Received on Wed Aug 23 2006 - 10:49:29 CDT

Original text of this message

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