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RE: Queries over DB Links

From: Toepke, Kevin M <ktoepke_at_cms.cendant.com>
Date: Thu, 01 Feb 2001 11:47:19 -0800
Message-ID: <F001.002A7BA6.20010201103204@fatcity.com>

Bill,

Also, you don't want to join remote tables together. Create a join-view on the remote database instead.

Kevin

-----Original Message-----
Sent: Thursday, February 01, 2001 1:10 PM To: Multiple recipients of list ORACLE-L

Bill,

    Queries across DB links are pretty messy. Check Metalink I found some information there, particularly on tuning SQL*Net/Net8. Outside of that there
is not too much you can do. One thing you should try to minimize if possible is
queries that have a mix of local and remote tables. In that case since the local DB has no idea of what the indexes are on the remote system, it sometimes
decides that the best way is to create a temp table locally of all that remote
data * then perform the joins. Needless to say that temp table is not indexed.

Dick Goulet

____________________Reply Separator____________________
Author: Bill Becker <beckerb_at_mfldclin.edu>
Date:       2/1/2001 9:07 AM

Hello,

We seem to have more and more questions regarding query performance across DB Links, and how to improve it. I have the Gurry/Corrigan book, but can't find anything on this specific topic.
Can anyone point me to a good whitepaper or other article regarding query performance across DB Links? Thanks
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Author: Bill Becker
  INET: beckerb_at_mfldclin.edu

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Author: Toepke, Kevin M
  INET: ktoepke_at_cms.cendant.com
Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051
San Diego, California        -- Public Internet access / Mailing Lists
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