question [message #51450] |
Thu, 23 May 2002 08:42 |
willskaren
Messages: 8 Registered: March 2002
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Junior Member |
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hi,
databse is 24/7.if u want to export the whole database
with export utility, what should u consider ?
a) concurrent transaction will suffer
b) the database being exported will be locked
c) constraint may cause problem
Thanks!!!!!!!!!
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Re: question [message #51455 is a reply to message #51450] |
Thu, 23 May 2002 11:00 |
Grant
Messages: 578 Registered: January 2002
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Senior Member |
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Export is a read only transaction. Users are able to do updates, deletes, and inserts. If you use CONSISTANT=Y (used when you want a consistent snapshot of the database) then you may need a large rollback segment. If there are no changes being made to the DB then use CONSISTENT=N. You will not have locking or constraint issues and export runs very fast. See http://www.orafaq.net/faqdbabr.htm
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Re: question [message #51461 is a reply to message #51450] |
Thu, 23 May 2002 12:46 |
Sanjay Bajracharya
Messages: 279 Registered: October 2001 Location: Florida
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Senior Member |
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Grants post defines 'export' and what it is.
Although you have a 24x7 system, I am pretty sure that there will be times when activity is at a minimum. Run the export around this time. If you do need a consistent export, set the CONSISTENT=Y opttion, which may take a little more time than otherwise.
How big is the DB and how long does it usaully take to complete the export ? To expedite the export, set the buffer parameter to some appropriate value (example with 512K buffer)
EXP ... BUFFER=524288 CONSISTENT=Y
Cheers.
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