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Datapump import disable_archive_logging will still generate redo?

From: Ashish Lunawat <ashish.lunawat_at_gmail.com>
Date: Wed, 5 Sep 2018 17:37:09 +0800
Message-ID: <CAEzAyeC1rh_D67Poky7BggauBUcrzLztgz5RxYLKFqmeeBJ-WA_at_mail.gmail.com> 





Hi,



 I have a Oracle database version 12.2.0.1 running in noarchivelog mode. I`m
wondering if datapump import parameter TRANSFORM=DISABLE_ARCHIVE_LOGGING:Y
will reduce the redo generated and thus improve the import timing?



 I have an import of a LOB table which takes about 10 hours to import about
85GB of data. AWR reports show almost all the time spent on "log file
switch (checkpoint incomplete)" event. There were 3 redo log groups
configured with each member size 200MB.



 I increased to 6 groups with each member 1.5GB but I am still getting
these wait events accounting to 94% of the DB time. And now the Avg wait
for these events has gone up to about 34 seconds from 7-8 secs last time.



 How can I get rid of the log file switch (checkpoint incomplete) events?
Increase DBwriters? FAST_START_MTTR_TARGET?



Thanks


Regards,


Ashish


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Received on Wed Sep 05 2018 - 11:37:09 CEST












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