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Re: DBLINKs in critical production system

From: Stephane Faroult <sfaroult_at_roughsea.com>
Date: Mon, 30 Apr 2007 19:16:26 +0200
Message-ID: <4636246A.9040402@roughsea.com>


Ajay,

Besides security issues (which may not matter too much if your network is secure - I presume, from your address, that it is) and the horror stories about development databases cloned from production (hint: database links had been forgotten in the cloning process), for performance create a sample table (eg create table test_dblink as select * dba_objects where 1=2), then insert into this sample table locally and across the database link under SQL*Plus, with SET TIMING ON. It will tell you if the difference is acceptable to you. From my own experience, database link means performance divided by a factor two (more or less) - and I am talking LAN, not WAN. If once in a while your query takes 0.8 seconds instead of 0.4, nobody will care. If you have a batch that repeats the query 2 million times, it will run 0.4 * 2,000,000 seconds slower, and you may have some grumpy individual objecting to the batch taking one day longer than usual. As usual, it depends.

HTH Stéphane Faroult

Thotangare, Ajay (GTI) wrote:
>
> Yes I agree with your explanation. How different it is accessing data
> from db link and direct connection without dblink considering I have a
> very good separate IP/card for dblink
>
> regards,
>
> Ajay
>
> ------------------------------------------------------------------------
>
> *From:* Mitchell, Travis [mailto:Travis.Mitchell_at_vacationclub.com]
> *Sent:* Monday, April 30, 2007 11:03 AM
> *To:* Thotangare, Ajay (GTI); oracle-l_at_freelists.org
> *Subject:* RE: DBLINKs in critical production system
>
> Imagine sticking a post-it with username/password information on your
> monitor… db_links are just about the same, especially pre-10g because
> the passwords are not encrypted.
>
> I’ve walked in and found that my database is hung because I did a
> developer a favor so they could quickly pull some data from a
> production system. Their sql took forever, backup software tried to
> shutdown the development database but couldn’t because of said sql,
> ORA-600s and some relationship building with Oracle support ensued.
> This was pre audit everything requirements, so I would recommend that
> if you have to use them, make sure your security team and the business
> has it approved in writing. Technically they can cause problems but
> from a security standpoint you can be heavily exposed.
>
> -----Original Message-----
> *From:* oracle-l-bounce_at_freelists.org
> [mailto:oracle-l-bounce_at_freelists.org] *On Behalf Of *Thotangare, Ajay
> (GTI)
> *Sent:* Monday, April 30, 2007 10:43 AM
> *To:* oracle-l_at_freelists.org
> *Subject:* DBLINKs in critical production system
>
> Hi Group,
>
> I have a question about dblink. I always hear that
>
> - dblinks are not good in production system.
>
> - dblink , ohh!! not in critical production system
>
> - dblink are not safe
>
> Can anybody please let me know the reason for such comments on dblinks.
>
> regards,
>
> Ajay
>
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Received on Mon Apr 30 2007 - 12:16:26 CDT

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