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Cookie value used in DBAccess Interface

Seetharaman Iyer
Ranch Hand

Joined: Jun 25, 2010
Posts: 35
Hi,

I've a questions related to cookie

// Locks a record so that it can only be updated or deleted by this client.
// Returned value is a cookie that must be used when the record is unlocked,
// updated, or deleted. If the specified record is already locked by a different
// client, the current thread gives up the CPU and consumes no CPU cycles until
// the record is unlocked.
public long lockRecord(long recNo)
throws RecordNotFoundException;


What Sun is trying to mean about cookie here in this interface. Are they trying to mean like this :
"returned value is a cookie which is nothing but it's same as magic cookie value in database file ()" ?
or
we have to randomly generate cookie value for each lock and the same generated must be used while performing other tasks like unlock/delete/update?

Thanks in advance,
Seetha...
Roel De Nijs
Bartender

Joined: Jul 19, 2004
Posts: 4908
    
  10

I'll think you'll be able this question yourself, if you have a clear understanding of the lock-method itself. In ScjdFaq there is an excellent explanation of the purpose of this method.


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Seetharaman Iyer
Ranch Hand

Joined: Jun 25, 2010
Posts: 35
Roel, my question is not about the usage/functionalities of these methods . My concern is all about the cookie value which will be used in the method invocation.

The doc says :



Is this cookie value same as magic cookie value specified in the database file(first 4 byte numeric)?

Please clarify...
Roel De Nijs
Bartender

Joined: Jul 19, 2004
Posts: 4908
    
  10

If you know the purpose of the lock and unlock methods, you'll be able to answer the question yourself. If you have read the ScjdFaq (as I suggested) you would also have read that the magic cookie is just used to identify database files.
 
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