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Standby redo log on Standby [message #504387] Sun, 24 April 2011 12:12 Go to next message
gkrishn
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Registered: December 2005
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    GROUP#    THREAD#  SEQUENCE#     sizeMB ARC STATUS           T
---------- ---------- ---------- ---------- --- ---------------- -
         1          1        115        512 YES CLEARING         O
         2          1        116        512 YES CURRENT          O
         6          1        114        512 YES CLEARING         O
         4          1        112        512 YES CLEARING         O
         5          1        113        512 YES CLEARING         O
         3          1        111        512 YES CLEARING         O

6 rows selected.


    GROUP#    THREAD#  SEQUENCE#     sizeMB ARC STATUS     TYPE   
---------- ---------- ---------- ---------- --- ---------- -------
         7          1          0        512 NO  UNASSIGNED STANDBY
         8          1        116        512 YES ACTIVE     STANDBY
         9          0          0        512 YES UNASSIGNED STANDBY
        10          0          0        512 YES UNASSIGNED STANDBY
        11          0          0        512 YES UNASSIGNED STANDBY
        12          0          0        512 YES UNASSIGNED STANDBY
        13          1          0        512 YES UNASSIGNED STANDBY

7 rows selected.

Above result is from standby database.

I am trying to understand the concept of standby redo log.My stadby database protection_mode is MAXIMUM PERFORMANCE.Can someone explain above scenario, after log sequence 116 arrives... i read many articles but finding it hard to understand this concept.Appreciate any help
Re: Standby redo log on Standby [message #504392 is a reply to message #504387] Sun, 24 April 2011 13:49 Go to previous messageGo to next message
John Watson
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Registered: January 2010
Location: Global Village
Senior Member
Hi - I was trying to reverse engineer your post, to work out what queries you ran. But it's too much work. What are you trying to show? What's the problem?
Re: Standby redo log on Standby [message #504393 is a reply to message #504387] Sun, 24 April 2011 13:55 Go to previous messageGo to next message
gkrishn
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Registered: December 2005
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sorry for confusion.just want to know how it works

i did a log switch in primary and it archived seq#115 to local arch as well as standby arch destination.

1)Will it directly apply to database or write to standby
redo (TYPE=STANDBY) first ? and then to database?
Re: Standby redo log on Standby [message #504394 is a reply to message #504393] Sun, 24 April 2011 13:57 Go to previous messageGo to next message
John Watson
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Registered: January 2010
Location: Global Village
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I give up. If you won't say what your queries were, you can't expect anyone to interpret them.
Re: Standby redo log on Standby [message #504395 is a reply to message #504393] Sun, 24 April 2011 13:59 Go to previous messageGo to next message
gkrishn
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Registered: December 2005
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oh,you wanted to knwo what query. here you go

-- ONLINE LOGFILES .Size should match both sides
select lg.group#,lg.thread#,sequence#,lg.bytes/1024/1024 "sizeMB",lg.archived,lg.status,le.type,le.member from v$log lg,v$logfile le
where lg.group#=le.group#
/

-- STANDBY LOGFILES .Size should match both sides
select sg.group#,sg.thread#,sg.sequence#,sg.bytes/1024/1024 "sizeMB",sg.archived,sg.status,le.type,le.member 
from V$STANDBY_LOG sg,v$logfile le
where le.group#=sg.group#
/
Re: Standby redo log on Standby [message #504396 is a reply to message #504395] Sun, 24 April 2011 14:05 Go to previous messageGo to next message
John Watson
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Registered: January 2010
Location: Global Village
Senior Member
You will also need to give the command you used to start managed recovery (if you did start managed recovery.)
Re: Standby redo log on Standby [message #504397 is a reply to message #504395] Sun, 24 April 2011 14:09 Go to previous messageGo to next message
gkrishn
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Yes,recovery is already ON.its a live prod database

SQL> alter database recover managed standby database disconnect;

Database altered.

Re: Standby redo log on Standby [message #504398 is a reply to message #504397] Sun, 24 April 2011 14:10 Go to previous messageGo to next message
gkrishn
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Registered: December 2005
Location: Putty a dark screen
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i have setup DR its up and running...but still not clear on concept.Thanks
Re: Standby redo log on Standby [message #504399 is a reply to message #504398] Sun, 24 April 2011 14:20 Go to previous messageGo to next message
John Watson
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Registered: January 2010
Location: Global Village
Senior Member
You did not use the clause
USING CURRENT LOGFILE
when starting managed recovery, therefore your redo is being written to the standby logfile, then it is archived, then it is applied.
Re: Standby redo log on Standby [message #504400 is a reply to message #504399] Sun, 24 April 2011 14:27 Go to previous messageGo to next message
gkrishn
Messages: 506
Registered: December 2005
Location: Putty a dark screen
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You mean archive log sequence#115 arrives standby log_archive_dest_1
then it get written to standby log(TYPE=STANDBY)
then recovery happens from standby log(TYPE=STANDBY) (this also records to online redo log)

was the above steps correct ?
Re: Standby redo log on Standby [message #504402 is a reply to message #504400] Sun, 24 April 2011 15:05 Go to previous message
John Watson
Messages: 8268
Registered: January 2010
Location: Global Village
Senior Member
I don't know where your redo arrives, because you haven't given your log_archive_dest_% parameters.
That's enough for tonight, perhaps someone else can help.
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