RE: rules for database link usage
Date: Mon, 17 Feb 2014 16:05:11 +0000
Message-ID: <a27a30e092ae4a10a9c0d236f932878e_at_USMAIL2K1303.us.micros.int>
Bobby,
Could you say a bit more about the view issue (or point me towards some documentation)? One of the many fires we're fighting is a performance issue where a DB link is involved... We have not yet directly implicated the DB Link in the performance problem, but...
Thanks,
stephan
Stephan Uzzell
From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Bobby Curtis
Sent: Monday, 17 February, 2014 10:56
To: backseatdba_at_gmail.com; oracle-l_at_freelists.org
Subject: RE: rules for database link usage
Jeff,
This is a slippery slope. Database Links can be good; however, I've seen the wrong use of them where they cause a problems. Example, if you query a view on the remote side through a dblink, your wait times may go up because you have wait for the view to compile and then return the result set. This extends your connection and retrieval times.
If you have to use a database link, I would use materialized views on the remote side to keep the data readily available. This way you are not compiling on the fly and waiting for the result set to be returned.
Ideally, I try to keep the data as close as possible to where the execution is going to happen.
Just my 2cents.
Bobby
From: oracle-l-bounce_at_freelists.org<mailto:oracle-l-bounce_at_freelists.org> [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Jeff C Sent: Monday, February 17, 2014 10:48 AM To: oracle-l_at_freelists.org<mailto:oracle-l_at_freelists.org> Subject: rules for database link usage
What are you rules for using database links in a production application? We currently have an application that needs data from another database and I am torn between having them just use a database link or copying the data to their database using various methods. I am leaning towards duplicating the data because I prefer to not have this database dependent on the other or one causing havoc on the other. But I guess if that didn't matter what in general are your rules?
Jeff
-- http://www.freelists.org/webpage/oracle-lReceived on Mon Feb 17 2014 - 17:05:11 CET