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Understanding limitations of schema evolution

Hi, I am trying to understand the limitations of schema evolution and have read the material on http://www.objectdb.com/java/jpa/entity/schema as well as the link therein regarding manual schema update when changing a field’s name Yet, i am confused regarding how to handle the case where one re-factors a class by moving one if it's Fields to a different class. Is this case managable? Thanks... depends on the specific required changes. It is like asking "Could you please elaborate more on the nature and complexity of ...

 
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DB Doctor sets type to "unknown" for new fields

Hi, we are using ObjectDB 2.5.4_04 on Linux. We added two new Boolean fields to a persistable type and run DB Doctor on the exiting DB file in order to update the schema. The fields are added to the schema as expected, however their type is set to unknown - we were expecting Boolean. The attached DB file is what was produced by DB Doctor after adding the emergency and broadcast fields. If you run in DB Explorer ... We are struggling to understand then why updates like the following fail to change the value from null to false: UPDATE ...

 
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Not able to update records

Hi,   I am tring to update the simple object by using Update query by i am getting following exception [ObjectDB 2.4.4_15] javax.persistence.TransactionRequiredException Attempt to run update query when no transaction is active (error 611) at com.objectdb.jpa.JpaQuery.executeUpdate(JpaQuery.java:758) Following is the code i am executing   ... It schould then look like: EntityManagerFactory emFactory = Persistence . ...

 
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New to Product & Having An Issue

Greetings ObjectDB Users! I'm new to the product, and I've setup a simple test after reading the tutorial, and I'm running into some issues with queries, specifically querying by primary key.   I have a domain object class Called Department, which has a member of type DomainId.  DomainId has two member fields:  String accountId and String objectId.  The following code shows these two classes.... } I then setup a JUnit test case, like this: package test. test ;   .... imports ...

 
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ObjectDB Web Site - Terms and Conditions of Use

1. Terms By accessing and using this web site, you agree to be bound by these web site Terms and Conditions of Use, all applicable laws and regulations, and agree that you are responsible for compliance with any applicable local laws. If you ...

 
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can removing an entity throw an exception if the entity is in use?

Suppose you have an entity @Entity class A { ... } and other entities with references to A.   e.g. @Entity class B { A a; // explicit reference to A List<A> list; // list of A's Set<A> set; // set of A's Set untyped; // general collection that may include A's } Objectdb allows me to remove an instance of A, even if a managed B has some reference to that A. When I then find the B instance and try to reference the A, I get an EntityNotFoundException. ... You can try something like: SELECT DISTINCT b FROM A a , B b WHERE a = ...

 
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License Activation Change and Checking Activation

Hello! How does ObjectDB determine the machine ID? Yesterday I activated our license on my development laptop and today I tried to persist more than 1M objects. ObjectDB told me that it cant't do that because of the evaluation restrictions. Now I activated it again on the same machine and got a different activation code. With this code it works. The only difference I can think of is that my WiFi was disabled yesterday and today it's not. ... protection, but this technique is sensitive to changes like disabling a network adapter. You should include both activation ...

 
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Query for objects persisted within the same transaction

I have a question concerning reading uncommited entities with query, within active transaction. For example, I read data from file. Each line contains value of one of entity's attributes but those values are not unique, so it's possible to have a multiple instances of the same entity. To eliminate duplicates, after reading every line I first check using a query, if an entity with that attribute value already exists. If no - I create one and persist it.... with map to check for duplicates, as performance drop is like 20x - just tested. edit ...

 
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Optimization Question

One of our uses for your ObjectDB software is in maintaining the current state of a large number of data objects called tracks. These tracks change very frequently over time (every 10-15 seconds is not unreasonable), but they are also very large complex data structures so it's extremely difficult to identify exactly what fields have changed from one update to the next. Currently the following sequence executes when a track update comes in: - If it’s a new track simply add it to the database.... figure out exactly what, any suggestions? P.S. Really like the new website design, good work! ...

 
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best practice for DB recovery

Hi, I'm trying to come up with the best approach for supporting some kind of hot standby for my master DB. ... in the DAO layer).   Would something like this work or even feasible with objectdb or is there a more standard way ...