About Question enthuware.oce-jpad.v6.2.369 :

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johnlong
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About Question enthuware.oce-jpad.v6.2.369 :

Post by johnlong » Sat Dec 24, 2016 2:01 pm

As per section 3.4.4.2: When an application locks an entity with LockModeType.PESSIMISTIC_READ and later updates that entity, the lock must be converted to an exclusive lock when the entity is flushed to the database.
How do you interpret "exclusive lock". Why it has to be exactly PESSIMISTIC_WRITE? Could it be PESSIMISTIC_FORCE_INCREMENT?

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Re: About Question enthuware.oce-jpad.v6.2.369 :

Post by admin » Sun Dec 25, 2016 12:56 pm

Yes, it could be PESSIMISTIC_FORCE_INCREMENT as well, which is same as PESSIMISTIC_WRITE with version update.

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Re: About Question enthuware.oce-jpad.v6.2.369 :

Post by johnlong » Sun Dec 25, 2016 6:31 pm

It could have similar semantics, but it has different definition. Thank you.

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Re: About Question enthuware.oce-jpad.v6.2.369 :

Post by himaiMinh » Mon Aug 14, 2017 4:30 pm

For the second option explanation '.... without blocking other transactions reading the data".
I think we can modify this statement by adding " ...without blocking other transactions reading the data which was committed in a previous transaction."

When one transaction gets the pessimistic read lock, other transactions can read the entity's data in the database, but not the pending changes in the persistence context. After the transaction commits the changes to the database, other transactions need to refresh the entity.

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