Problem with database link from Oracle Version 6 to Oracle 7

From: Varunee Buerkle <v_buerkle_at_pnl.gov>
Date: 1995/04/18
Message-ID: <3mv7um$a3h_at_bbs.pnl.gov>#1/1


I hope all the Oracle expert out there can help me with my problem.

We have a medium size of production database version 6 that we are currenthly converted some of the application to Oracle 7. We can not converted all the application over a weekend. So we migrate a few applications at a time to Oracle 7. We have Oracle 7 up and running under production about 1 week. We run in to a serious performance problem for the queries running from Oracle 6 and accessing some of the tables that are in Oracle 7.

Our production job that used to run 2 hrs and produce over 200 reports, is now running over 10 hrs and produced only half of the reports. We have to kill the queries, and copy the table bak to Oracle 6 to finish up the rest of the reports.  

The queries is submitted from Oracle Version 6 with some of the table use in the query reside in Oracle 7. I created database link in Oracle Version 6 , so the queries can see the table that are in Oracle 7. Well, the queries can see fine, the problem is taking a very long time to produce a report. I ran an explain facility from Oracle 6 first with the copy of the table in Oracle 6, the plan show the query is using INDEX, and it ran very fast. Then I dropped the table from Oracle 6 and created the link point to Oracle 7, ran the explain and it show nothing about the table in Oracle 7, except saying it is remoted. I believe it is doing a full table scan for the table in Oracle 7.

I called Oracle about the problem, it looks like a complex problem now. I am still waiting to hear from Oracle. Meanwhile, can anyone give me any info? Has anyone run into a similar situation ? Thank you for any help.

Varunee Buerkle
Fax 509-375-6703
E-mail:v_buerkle_at_pnl.gov Received on Tue Apr 18 1995 - 00:00:00 CEST

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