About database

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Tutorial
11

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
11

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
11

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
11

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
11

Database(*.odb) file size on disk

Hello, we have questions about the file size of ObjectDB database on disk. Can you tell ... memory always used by new entities? -Will be the database file automatically reduced?   We have created ... are reused but the the file not resized. The database is at the end empty again, but larger
Forum
11

How to define database structure and insert some initial objects from scratch

the initial database structure of our application? We know objectdb is all about objects and probably doesn't ... jdbc driver for ETL software like Kettle? How about migrating data from another database system? Thanks in advance! To populate the database you will have to write Java code. That code
Forum
11

Using multiple databases

Is it possible for an ObjectDB PersistenceManger/EntityManager to connect to more than one database at a time? Also, can objects in one database reference objects in another database (e.g. through globally unique identifiers)? You can use as many databases as needed at the same time but each
Forum
11

Database absolute filepath

Is there a line of code that can be used to print out my databases absolute path? I have set it as follows: EntityManagerFactory emf = Persistence.createEntityManagerFactory("$objectdb/database/people.odb"); However, the data being shown in \lib\objectdb\database\people.odb is different
Forum
11

Master database switching to read-only mode, possibly caused by slave failure

We had a database failure causing a production outage. Both master and slave databases have failed ... database failed first and possibly caused the master to switch to read-only mode. The sequence ... - MASTER instance stopped responding to write requests. All requests sent to the database during 3
Forum
11

Multi-Threading/Distributed-Database Questions...

Greetings ObjectDB team, All below questions assume a very large database (~1,000,000,000 objects ... : Is it true that two read-only JPQL queries accessing the same database file actually run simultaneously ... to use two database files on two different physical hard disks while still being able to cross reference