26 | Is ObjectDB scalable? What are its limitations?. Up to 9,223,372,036,854,775,808 entity objects per database file. Unlimited database connections (limited by operating system resources). ... 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 |
22 | JPA Primary KeyEvery entity object that is stored in the database has a primary key. Once assigned, the primary key cannot be modified. It represents the entity object as long as it exists in the database. As an object database, ObjectDB supports implicit object IDs, so an explicitly defined primary key is not |
22 | Locking in JPA in ObjectDB (and in JPA) is always at the database object level, i.e. each database object is locked separately. Optimistic locking is applied on transaction commit. Any database object ... is being performed on an old version of a database object, for which another update has already been committed |
20 | FROM clause (JPQL / Criteria API) identification variables that iterate over all the database objects of a specific entity class ... over all the Country objects in the database: SELECT c FROM Country AS c The AS keyword is optional ... . Caution is required when using multiple range variables. Iteration over about 1,000,000 database objects |
3 | 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 |
2 | [ODB1] Chapter 2 - A Quick Tour instances. ObjectDB, as a pure object database, can simply store a memory data structure in the database ... method (line 25). An object bound to the database during an active transaction, is expected to be stored physically in the database when the transaction is committed (line 37). Note: Memory objects |
2 | [ODB1] Chapter 1 - About ObjectDBObjectDB for Java/JDO is a powerful Object Database Management System (ODBMS) written entirely in ... of them. ObjectDB is an Object Database Developing object oriented applications with ObjectDB is easier and much more effective because the content of the database is application objects. Whereas, working |
2 | [ODB1] Chapter 3 - Persistent Classes. Instances of these classes that represent objects in the database are called persistent objects or persistent instances. Objects that do not represent anything in the database (including instances ... Fields and Types Storing a persistent object in the database does not store methods and code |
2 | [ODB1] Chapter 4 - JDO Metadata in the JDO specification, are ignored by ObjectDB if specified (as a pure object database, ObjectDB always uses datastore identity with its own object-id class). 4.3 Metadata for Fields Unlike ... . When a persistent object is retrieved from the database its fields are not ready yet. Only when the program |
2 | [ODB1] Chapter 7 - JDOQL QueriesThere are various ways to retrieve objects from an ObjectDB database, as shown in section 6.3 ... for RDBMS. It provides object retrieval from the database according to a specified selectioPlan ... compilation succeeds, the Extent of Person instances in the database is iterated object by object |
