About lock

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JPA Doc
3

setHint(hintName, value)

timeout hint. Depending on the database in use and the locking mechanisms used by the provider
JPA Doc
3

setHint(hintName, value)

on the standard timeout hint. Depending on the database in use and the locking mechanisms used by
JDO Doc
3

setOptimistic(optimistic)

Method javax.jdo.Transaction void setOptimistic(   boolean optimistic ) Optimistic transactions do not hold data store locks until commit time. If an implementation does not support this option, a JDOUnsupportedOptionException is thrown. Parameters: optimistic - the value of the Optimistic flag. Since: JDO 1.0
Issue
3

Query fails with failed to read

because another process has locked a portion of the file" shows some results that may be relevant, for example: https ... -cannot-access-the-file-because-another-process-has-locked-a-portion-of-the-file-57?forum ... a lock by your application process with the embedded ObjectDB but by a different process (anti-virus
Forum
3

Several parallel threads to speed up query on one DB

used to do a clear after running each query - The lock contention disappears when I removed the "em ... (timeline) and the lock contention view. You can see that Thread R1 is running smoothly with no lock ... - and they seem to get to lock each other many times for small amount time. Thanks Thank you for the test case. Some locking
Forum
2

How to do multithreading with embedded ObjectDB

, rather than concurrently:     synchronized (lock) {         em.createQuery("UPDATE Point SET x = x + 1").executeUpdate();     } Your lock object must be one object that is shared by all the threads. 2. Use ObjectDB / JPA locking, by setting a pessimistic locking timeout, e.g. by: Map
Forum
2

OptimisticLockException

._OptimisticLockException: Optimistic lock failed for object model.UserSession#28 (object has version ... will attach Optimistic locking is enabled by ObjectDB automatically even if no version field is defined. You can disable optimistic locking checks (and eliminate these exceptions) but first verify
Forum
2

Remove an entity which attributes were changed - OptimisticLockException

the entity from the database. After commit the transaction an exception is caused with optimistic lock ... . You may also disable optimistic locking checks if you do not need it. We use only one entity ... , if invoking the operations in different plugins. This leads to the optimistic lock exception
Forum
2

Setting temp directory location in ObjectDB

. This might be a side effect of the file locking method that is used by ObjectDB 1.x. Try running ObjectDB in a process ... permission permission is blocked for the parent folder, won't ObjectDB locking method throw exceptions ... . > And if write permission permission is blocked for the parent folder, won't ObjectDB locking method throw
Forum
2

Some technical questions

Hi, ObjectDB looks interesting. Have two technical questions... (1) what locking model does ... you, Andrej (1) what locking model does ObjectDB use? I.e. 2PL or MVCC? Do writers block readers? Do readers block writers? ObjectDB implements the standard JPA locking model - see this manual page. (2