RE: import table scan

  • From: Guang Mei <GMei@xxxxxx>
  • To: "'Chris.Judd@xxxxxxxxxxxxxxx'" <Chris.Judd@xxxxxxxxxxxxxxx>, oracle-l@xxxxxxxxxxxxx
  • Date: Thu, 23 Jun 2005 10:43:07 -0400

For Export , try 

For Import, try

analyze=n  , you can analyze table after imp finishes
also put DB in no-archive log mode to reduce redo log writing
you could also skip index import, only load data first, then rebuild indexes
with nologging



-----Original Message-----
From: oracle-l-bounce@xxxxxxxxxxxxx
Sent: Thursday, June 23, 2005 10:30 AM
To: oracle-l@xxxxxxxxxxxxx
Subject: RE: import table scan

We have a big oracle database, in the 2 TB size range.  The database
stores aerial imagery and 99% of the storage is in 15-20 tables.  Our tables
are huge.  Query performance from the database is great, but importing the
export of this database takes a good deal of time, as one might expect.  

I made the decision to do import/export because we don't have archive
and I can't bring the database down long enough to copy the datafiles, and
import/export is easier to test.  However, the import process spends ½ of
time (I'm estimating) doing table scans.  I witness this by going into OEM
and viewing the  Long Operations tab of the session.  

I used the following for the export: exp  \'sys/xxx @raster as sysdba\'
buffer=20000000 file=/rasterbu1/rasterbu.dmp full=y COMPRESS=y consistent=n

and this for the import: imp \'sys/xxx as sysdba\'
file=/rasterbu1/rasterbu.dmp log=imp.log full=y

I don't have any reason to believe the database import will not work, but I
would like to speed it up if possible.

Thanks for your help,


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