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Home -> Community -> Mailing Lists -> Oracle-L -> RE: Hot Backup Issue
Guy,
I would have thought 2) was best as you are reducing the concurrency (I think that is the right word) of redo log activity.
As each tablespace is in backup mode it writes the full block to the redo log when any changes are made. On the assumption that all tablespaces are being written (albeit infrequently) during the period of hot backup it is better to alter each tablespace, copy it then alter online again so that only 1 tablespace at a time is having full blocks of changed data writing to the redo logs.
The overall level of redo will be the same but contention (ah ha - better word) will be reduced
John
-----Original Message-----
From: Guy Hammond [mailto:guy.hammond_at_avt.co.uk]
Sent: 02 October 01 12:15
To: Multiple recipients of list ORACLE-L
Subject: RE: Hot Backup Issue
Hello,
Slightly unrelated question... is it better to (in pseudo code) :
1)
for each tablespace loop
put tablespace in backup mode
end loop
for each datafile in the database loop
copy data file
end loop
for each tablespace loop
put tablespace in normal mode
end loop
or 2)
for each tablespace loop
put tablespace in backup mode
for each datafile in this tablespace loop
copy data file
end loop
put tablespace in normal mode
end loop
What I'm doing is (2), but I notice that Rajesh is doing (1). What are the pros and cons of each approach? (I'll probably use RMAN at some point, anyway :0) ).
Cheers,
g
-- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Guy HammondReceived on Tue Oct 02 2001 - 07:35:29 CDT
INET: guy.hammond_at_avt.co.uk
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