RE: a question to question

From: Dunbar, Norman (Capgemini) <"Dunbar,>
Date: Fri, 14 Jan 2011 11:28:21 -0000
Message-ID: <919FC80F27E0C6428106496EDF92A75210C402EA_at_EXCCLUS05.PRODDS.NTNL>


>> TK 2: Which two steps are performed the first time any
>> Update statement is issued after the instance is started ?
>> Choose two

>> A. Creating the parse tree of the statement
>> B.Writing the modified data blocks to data files
>> C.Writing the modified data to the archived redo log files
>> D.Updating the control file to indicate the most recent checkpoint
>> E.Updating the data file header to indicate the most recent
>> checkpoint
>> F. Reading the blocks to database buffer cache if they are
>> not already there

>> The answer is provided as C and D.

I would say that that is incorrect!

>> Concluding A and F

I agree.

Given that the question specifically states "the first time... any update.." implies at least a hard parse is required for the statement. It is the first time the statement has been issued after the startup, so A is at least one of the answers.

And given that this is an update, and blocks can only be updated in the cache, then the blocks to be updated must first have to be read into the cache. So F is also one of the answers.

B, D & E are incorrect as it is the DBWR that actually writes the modified blocks from the cache at some point. CKPT does the check pointing and header writing. They are background processes and are not necessarily activated by executing an update statement.

C is incorrect as that only happens after an online redo log fills up.

I suggest you avoid that particular web site, but given also that even Oracle gets it hopelessly wrong a lot of the time, even in the exams themselves, what can you do?

>> Or may be I do not understand the question well as English is not my
>> primary language.

No, there is nothing wrong with your English.


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Received on Fri Jan 14 2011 - 05:28:21 CST

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