| Import first 1GB very fast, then slows down 9.2.0.4 [message #73517] |
Thu, 13 May 2004 12:56  |
Keith Sandberg
Messages: 4
Registered: May 2004
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Junior Member |
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I am migrating a 6GB database from 8.1.7.4 to 9.2.0.4. The hardware is Sun v450's running Solaris 9.
I use the 8.1.7.4 EXPORT command to create my dump file. I have no tables with LONG's.
I use the 9.2.0.4 IMPORT command to load the dump file, using the following syntax:
IMP file=<filename> full=y ignore=y indexes=n constraints=n analyze=n feedback=5000 commit=n buffer=10000000
The import screams through the first 50 tables... over 1GB worth of data is loaded within the first hour, which is pretty good. There are two tables with over 3M rows in this bunch. But then, for no reason I can determine -- IMP gets really slow. Right now, a 170MB table with 1.8M rows has taken over 2 hours, and it's still not done. Again, there are NO LONG's in my data (I know enough not to IMP tables with LONG's). I have disabled all triggers and constraints.
Any ideas what might be going on? My UNDO and my TEMP tablespaces appear to be fine.
Thanks in advance for any help you can provide.
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| Re: Import first 1GB very fast, then slows down 9.2.0.4 [message #73530 is a reply to message #73517] |
Mon, 17 May 2004 07:20  |
Keith Sandberg
Messages: 4
Registered: May 2004
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Junior Member |
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Before I did the import, I was running a script (in effect) that would create all my objects in the target database first.... I did this because my tablespace names are different in 9i, and I wanted to ensure that my tables and indexes are in the right place. The tablespaces are LMT... the tables and indexes are all created with an initial extent equal to their current size... so I know space management is not the problem.
Some of my tables have constraints and triggers. My script was creating these objects, then disabling them. However, it appears that the IMPORT was applying the triggers and constraints anyway.
This morning, I created all my objects, as normal, except for the constraints and triggers. My IMPORT is blazing away.... I've already loaded over 3GB in about 90 minutes... it looks like my total load is gonna be about 3 hours. It was taking 12 hours. Very cool!
Should I assume that it is good practice, in my case, to disable all my constraints and triggers in the source database first, BEFORE I do an export??? SO that the IMPORT does not use the triggers when importing?
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