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
Title: 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
well 1 is simpler to code. :)
However, if you put all tablespaces in backup mode at once, you will be
generating a LOT of extra redo and archived logs.
That's because even if you are not currently backinf up that tablespace
(say you already HAVE backed it up), you will still have to write full
Guy,
Some reasons why NOT to put all tablespaces in the backup mode at once (step 1) is
that the tranactions against the database could create a lot of redo and archive logs
that could fill the space, tranaction time could be longer as it now reads the redo
not the tables, Snapshot to old
The main disadvantage of #1 is that lgwr will write full blocks to the redo logs
for the entire database until the entire backup is finished. If that takes a
while and there is significant activity, it can generate tremendous amounts of
redo - and archive. Lgwr and the I/O subsystem are doing
Title: RE: Hot Backup Issue
That
makes sense, I just wanted to check :0) And of course, transactions in other
tablespaces would be writing redo as normal. The overall level of redo generated
would surely be less, tho'? Because say you had 5 tablespaces and put them all
into hotbackup mode
On Tue, 2 Oct 2001, Ron Rogers wrote:
Some reasons why NOT to put all tablespaces in the backup mode at
once (step 1) is that the tranactions against the database could
create a lot of redo and archive logs that could fill the space,
tranaction time could be longer as it now reads the redo
-Original Message-
Sent: Tuesday, October 02, 2001 11:25 AM
To: Multiple recipients of list ORACLE-L
On Tue, 2 Oct 2001, Ron Rogers wrote:
Some reasons why NOT to put all tablespaces in the backup mode at
once (step 1) is that the tranactions against the database could
create a
I think, I need to answer this original post( late,
because our time zone is different ;-))
I was doing this in the test environment ( which I
mentioned in my original post too) with total database
size of 250 Mb. To make the testing easier I had adopted
some random method. At that
I am making the assumption here that you are doing
recover database using backup controlfile when you do the backup
In this case, what is happening to you is normal. The controlfile
doesn't know what the last scn is supposed to be, so all you have to do
is cancel the recovery once the last
Rachel,
You are absolutely right!!
Just after dropping the mail I continued with the tests,
and discovered the same theory.
Thanks a lot for reply.
Best Regards,
Rajesh
-Original Message-
Carmichael
Sent: Monday, October 01, 2001 4:45 PM
To: Multiple recipients of list
hi,
i feel u need to give the name of online redo log file after u had applied
all the archived log files, if it's asking for more files.
this should solve ur problem.
pls let me know if it not. i'll try finding other issues also.
saurabh
- Original Message -
To: Multiple recipients of
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