| Standby redo log on Standby [message #504387] |
Sun, 24 April 2011 12:12  |
gkrishn
Messages: 506
Registered: December 2005
Location: Putty a dark screen
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Senior Member |
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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
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| Re: Standby redo log on Standby [message #504393 is a reply to message #504387] |
Sun, 24 April 2011 13:55  |
gkrishn
Messages: 506
Registered: December 2005
Location: Putty a dark screen
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Senior Member |
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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?
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| Re: Standby redo log on Standby [message #504395 is a reply to message #504393] |
Sun, 24 April 2011 13:59 |
gkrishn
Messages: 506
Registered: December 2005
Location: Putty a dark screen
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Senior Member |
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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#
/
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| Re: Standby redo log on Standby [message #504399 is a reply to message #504398] |
Sun, 24 April 2011 14:20 |
John Watson
Messages: 8880
Registered: January 2010
Location: Global Village
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Senior Member |
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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.
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| Re: Standby redo log on Standby [message #504400 is a reply to message #504399] |
Sun, 24 April 2011 14:27 |
gkrishn
Messages: 506
Registered: December 2005
Location: Putty a dark screen
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Senior Member |
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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 ?
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