Log switch query [message #312008] |
Mon, 07 April 2008 14:17  |
oraclesavvy
Messages: 9 Registered: May 2007
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Junior Member |
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Hello,
This question was asked to me during the interview which I couldn't answer as lack of knowledge. The question is as follows:-
During the log switch the log member's status which is being switched changes from active to inactive for a while and again comes back to active...why?
Please correct me if my query is wrong but this query was asked to me.
Regards.
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Re: Log switch query [message #312112 is a reply to message #312009] |
Tue, 08 April 2008 00:41   |
oraclesavvy
Messages: 9 Registered: May 2007
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Junior Member |
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Yes it is true.
It has logical reason.
If a log member is being written to, its status is 'CURRENT', as soon as log switch occurs, its state is 'ACTIVE' for the time till the data is written to the datafiles, after which it becomes 'INACTIVE'. After this it never becomes 'ACTIVE' again till again log switch occurs and the cycle repeats itself. But a log group never goes from the 'INACTIVE' state to the 'ACTIVE' state directly.
Regards.
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Re: Log switch query [message #312184 is a reply to message #312158] |
Tue, 08 April 2008 02:48   |
Frank
Messages: 7901 Registered: March 2000
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Senior Member |
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Note that Michel is not asking you because he does not know. By asking these questions, he shows you the way to get (and reason) the answer to your question.
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Re: Log switch query [message #312194 is a reply to message #312184] |
Tue, 08 April 2008 03:04   |
oraclesavvy
Messages: 9 Registered: May 2007
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Junior Member |
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Active - It indicates that online redo log file group is active but not the current online redo log file group. It may be in use for recovery or may not be archived.
Current - The group which is being used.
Inactive - Indicates that online redo log file group is no longer required for instance recovery. It may or may not be archived.
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Re: Log switch query [message #312239 is a reply to message #312209] |
Tue, 08 April 2008 05:00   |
oraclesavvy
Messages: 9 Registered: May 2007
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Junior Member |
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You didn't read my question carefully...I am talking about what happens during log switch...and it is true that log member changes it status.
Log member being switch - status current
Log member after log switch - status active till data is written to
datafiles.
Once data has been written to datafiles, it's status never becomes active till next log switch.
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Re: Log switch query [message #312246 is a reply to message #312239] |
Tue, 08 April 2008 05:08  |
pablolee
Messages: 2882 Registered: May 2007 Location: Scotland
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Senior Member |
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The point is that your first question:
Quote: | During the log switch the log member's status which is being switched changes from active to inactive for a while and again comes back to active...why?
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Can actually be answered by your observations, therefore the answer to the question
Quote: | Can a log file go from current to inactive to active (to inactive)?
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