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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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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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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 ...

 
forum_thread

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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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 ...

 
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Double persist of Entity field with Cascade.ALL

I am building a JavaEE application using Netbeans 7.0.1, Glassfish 3.1 and ObjectDB 2.3.3. I have a Book class with entity field Chapter which has a CascadeType.ALL property. The Book fields are as follows: @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; private String bookTitle; @OneToMany(cascade= CascadeType.ALL, fetch= FetchType.EAGER) private List<Chapter> chapters; The Chapter fields are as follows: ... all the classes involved in the error case. I would like to know if there is a way I can make the error case scenario work as that ...

 
issue

Issue with DISTINCT Select

It is getting more and more frustrating :( We've introduced distinct select instead of regular selection in our code (no changes else) and suddenly receive invalid identifiers in queries exceptions in various queries. Here's the stacktrace: ... having a result with doubled $1 and stilll use something like our code? thanks, Alex ... Sorry but still not working it looks like I am too dumb!? Using this query on attached DB: SELECT ...

 
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Replication issue, Replayer failing due to NullPointerException.

I'm getting replication errors and upon trying to play the replayer I get a NullPointerException which i'm also seeing in the slave logs when it's trying to replicate... ... into the directory above it(the "data path"), this seems like a bug. I was seeing errors along the lines of the user had no ... by resize value across all DB's, this also seems like a bug. I have recording set to write only.   ...

 
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String Encoding Issue

Hi all Encounter a character encoding issue when i try to retrieve a String column containing Chinese character. Retrieve a String column on odb file.  em = emf.createEntityManager(); Query query = em.createQuery("SELECT fu FROM FarmUnit fu"); But, when try to print the value out as: #1 2011-06-23 04:30 Hi all Encounter a character encoding issue when i try to retrieve a String column containing Chinese cha ...