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Issue
12

query returns failed to read from database file

there is no message       it seams that this is only happening directly after startup (creating the database ... the database connection, factory ...), hundreds of requests (including the queries) are then received
Manual
12

Deleting JPA Entity Objects

Existing entity objects can be deleted from the database either explicitly by invoking the remove ... from the database it has to first be retrieved (no matter which way) and then in an active ... (); The entity object is physically deleted from the database when the transaction is committed. Embedded
FAQ
12

Is ObjectDB scalable? What are its limitation?

ObjectDB is highly scalable and can manage efficiently databases in a wide range of sizes, from ... supports: Database file size up to 128 TB (= 131,072 GB = 134,217,728 MB). Up to 2,147,483,648 entity classes per database file. Up to 2,147,483,648 indexes per database file
Tutorial
12

Step 4: Add a Servlet Class

ServletException, IOException { // Obtain a database connection: EntityManagerFactory ... { // Close the database connection: if (em.getTransaction().isActive ... is retrieved from the application scope attribute, and then an EntityManager (representing a database
Tutorial
12

Step 4: Add a Servlet Class

{ // Obtain a database connection: EntityManagerFactory emf = (EntityManagerFactory ... ") .forward(request, response); } finally { // Close the database ... , and then an EntityManager (representing a database connection) is constructed. If a new guest
FAQ
12

What is the Java Persistence API (JPA)?

The Java Persistence API (JPA) is a standard API for accessing databases from within Java applications. The main advantage of JPA over JDBC (the older Java API for interacting with databases ... . Using plain old Java objects (POJO) to represent persistent data can significantly simplify database
FAQ
12

Which API should I use - JPA or JDO?

code. When to prefer JDO JDO might be preferred when portability to other object databases is more important than general portability to both object and relational databases. JPA is designated to be used mainly with relational databases. ObjectDB is the only object database that supports JPA
Forum
12

@SequenceGenerator and single id in whole database

strategy is Auto, which causes global ID's per database, not per class?   Yes, that is correct
Forum
12

Benchmark native JPA of Versant database (without datanucleous)

Now Versant DB (db4o commercial) has JPA implementation    Can you benchmark this Object Oriented DB to compare with Object DB? Since the Versant Object Database (unlike db4o) is not open source it would be impossible to include it in the JPAB benchmark results without the consent of Versant
Forum
12

Cache configuration of database file pages, query programs, query results

Are there some possibilities to configure following caches in order to keep cache data for only some important entity types and for the entire life cycle of the EntityManagerFactory. Cache of database file pages. Cache of query programs. Cache of query execution results. These caches are fully