ObjectDB Database Search

Databases are also supported by ObjectDB. The combination of Object Database features ... . Up to 9,223,372,036,854,775,808 entity objects per database file. Unlimited database connections ... database files (the ObjectDB Doctor ). Standard Persistence APIs ObjectDB is the only Object -Oriented

solution. Using a relational database management system (RDBMS) to store and retrieve Java objects requires slow conversions between graphs of Java objects and flat database table rows. Object Relational ... with a database . ObjectDB is an extremely easy to use pure Java Object Database , which supports JPA

. However, you should consider the following points when doing your own objective comparison of object databases : ObjectDB is unique in supporting the standard APIs. It is the only object database with built in ... of the Java Data Objects (JDO) API than competing object databases . By using a standard API such as JPA

of a single field in a single database object . This type of viewer is useful for viewing data ... object models, is preferred. A Tree window displays objects as a tree. Every database object ... windows provide easier navigation. Because every reference between two database objects is represented by

The Java Persistence API (JPA) provides various ways to retrieve objects from the database ... of the database . The persistence context serves as a cache of retrieved entity objects . If a requested ... with data that is retrieved from the database (or from the L2 cache - if enabled). The new entity object

The configuration element specifies back end ( database engine) settings that are relevant ... :    The element The element specifies the database file and page size settings: The initial attribute specifies the initial size of every new database file. The resize attribute specifies

In JPA a database connection is represented by the EntityManager interface. Therefore, in order to manipulate an ObjectDB database we need an EntityManager instance. Operations that modify database ... of EntityManagerFactory that represents the relevant database and then we can use that factory instance

), which can represent physical objects in the database . Managing an ObjectDB Object Database using JPA ... database objects . Entity Object Life Cycle The life cycle of entity objects consists of four states ... the database . An entity object becomes Managed when it is persisted to the database

entity class. This is done automatically in memory each time the entity object is loaded. The database object is only updated to the new schema when that entity object is stored to the database ... of an entity class are detected by ObjectDB. New entity objects have to be stored in the new class

Given an EntityManager , em , that represents a JPA connection to the object database , we can use it to store, retrieve, update and delete database objects . Storing New Entity Objects The following code fragment stores 1,000 Point   objects in the database : em. getTransaction (). begin

New entity objects can be stored in the database either explicitly by invoking the persist method ... its state to Managed. The new entity object is stored in the database when the transaction ... class. Only instances of entity classes can be stored in the database independently. Objects

To access relational databases using the Java Persistence API (JPA) you will need an Object ... . The DataNucleus ORM implementation supports also the Java Data Objects (JDO) API. ObjectDB is a full featured standalone Object Database Management System (ODBMS) and not an ORM tool, so it is not intended and cannot be used to access other database management systems.

, but they are easier to use in object oriented languages such as Java. In addition, unlike most other NoSQL databases ... ObjectDB is a unique NoSQL database . It doesn't have the known disadvantages and limitations ... ). Therefore, ObjectDB can be used in applications that cannot use conventional non ACID NoSQL databases because of a requirement for a very high level of consistency.

Detached entity objects are objects in a special state in which they are not managed by any EntityManager but still represent objects in the database . Compared to managed entity objects , detached ... the database unless modified detached objects are merged back into an EntityManager to become managed

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

Modifying existing entity objects that are stored in the database is based on transparent ... Once an entity object is retrieved from the database (no matter which way) it can simply be modified in memory ... (); The entity object is physically updated in the database when the transaction is committed

As noted above, using ObjectDB instead of a relational database and ORM combination  ... of a relational database is mandatory (e.g. as a result of a customer request or when a new application is developed for an existing old relational database ). By using the Java Persistence API (JPA

A connection to a database is represented by an EntityManager instance, which also provides functionality for performing operations on a database . Many applications require multiple database ... database connection, using a separate EntityManager instance, for every HTTP request. The main role

, the same database is managed on multiple machines (nodes), possibly in different geographic locations ... master-slave replication, the master node manages the main (master) database , which supports Read / Write operations. The other (slave) nodes in the cluster manage identical copies of the same database

database file Checks a given ObjectDB database file, verifies that it is healthy and valid ... of a corrupted ObjectDB database file Repairs a corrupted ObjectDB database file by creating a new fresh database file and then copying all the recoverable data in the corrupted database file

can apply recorded database operations on a matching database backup (if available). This ability is useful for two different purposes: It enables recovery from a database failure by replaying ... & Recording Files When recording is enabled , ObjectDB maintains for every database file a recording

ObjectDB Server is a tool that manages ObjectDB databases in a separate dedicated process, making these databases accessible to client applications in other processes including ones on other remote ... are: The ability to access and use databases from different processes simultaneously. The ability to access

All about ObjectDB Database in Java/JPA database - explanations, examples, references, links and related information.

Describes the ObjectDB object database tools - the Explorer, the Server, the Enhancer, the Doctor and the Replayer.

Every 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

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

; Object entity ,    LockModeType lockMode ,    LockOption... options ) Lock ... the database lock. If these checks fail, the OptimisticLockException is thrown. If the lock mode type ... if the database locking failure causes transaction-level rollback the LockTimeoutException is thrown

; Object entity ,    LockModeType lockMode ,    Map properties ) Lock an entity ... , the persistence provider must also perform optimistic version checks when obtaining the database ... if the database locking failure causes transaction-level rollback the LockTimeoutException ia thrown

; Object entity ,    LockModeType lockMode ,    Map properties ) Refresh the state of the given managed entity instance from the database , overwriting unflushed changes ... is thrown if the database locking failure causes transaction-level rollback the LockTimeoutException

; Object entity ,    RefreshOption... options ) Refresh the state of the given managed entity instance from the database , using the specified options , overwriting changes made to the entity ... : the PessimisticLockException is thrown if the database locking failure causes transaction-level rollback

; Object entity ,    LockModeType lockMode ) Refresh the state of the given managed entity instance from the database , overwriting unflushed changes made to the entity, if any, and obtain ... : the PessimisticLockException is thrown if the database locking failure causes transaction-level

; Object entity ,    LockModeType lockMode ) Lock an entity instance belonging ... checks when obtaining the database lock. If these checks fail, the OptimisticLockException is thrown ... : the PessimisticLockException is thrown if the database locking failure causes transaction-level rollback

; EntityGraph entityGraph ,    Object primaryKey ,    FindOption... options ) Find ... when obtaining the database lock. If these checks fail, the OptimisticLockException is thrown. If the lock ... : the PessimisticLockException is thrown if the database locking failure causes transaction-level rollback

entityClass ,    Object primaryKey ,    LockModeType lockMode ,    Map ... when obtaining the database lock. If these checks fail, the OptimisticLockException is thrown. If the lock mode ... : the PessimisticLockException is thrown if the database locking failure causes transaction-level rollback

entityClass ,    Object primaryKey ,    FindOption... options ) Find an instance ... optimistic version checks when obtaining the database lock. If these checks fail ... but cannot be locked: the PessimisticLockException is thrown if the database locking failure causes transaction-level

entityClass ,    Object primaryKey ,    LockModeType lockMode ) Find by primary ... attribute, the persistence provider must perform optimistic version checks when obtaining the database ... if the database locking failure causes transaction-level rollback the LockTimeoutException is thrown

Jakarta Persistence (JPA) Method in jakarta.persistence.PersistenceUnitUtil Object getIdentifier (    Object entity ) Return the id of the entity. A generated id is not guaranteed to be available until after the database insert has occurred. Returns null if the entity does not

Jakarta Persistence (JPA) Method in jakarta.persistence.PersistenceUnitUtil Object getVersion (    Object entity ) Return the version of the entity. A generated version is not guaranteed to be available until after the database insert has occurred. Returns null if the entity does not

Jakarta Persistence (JPA) Method in jakarta.persistence.EntityManager void refresh (    Object entity ) Refresh the state of the given managed entity instance from the database ... : EntityNotFoundException - if the entity no longer exists in the database . IllegalArgumentException

; Object entity ,    Map properties ) Refresh the state of the given managed entity instance from the database , using the specified properties, and overwriting unflushed changes ... Throws: EntityNotFoundException - if the entity no longer exists in the database

Jakarta Persistence (JPA) Method in jakarta.persistence.EntityManager void persist (    Object entity ) Make a new entity instance managed and persistent, resulting in its insertion in the database when the persistence context is synchronized with the database , or make a removed entity

Jakarta Persistence (JPA) Method in jakarta.persistence.EntityManager void remove (    Object entity ) Mark a managed entity instance as removed, resulting in its deletion from the database when the persistence context is synchronized with the database . This operation cascades

; Class entityClass ,    Object primaryKey ) Obtain a reference to an instance ... instance does not exist in the database , the EntityNotFoundException is thrown when the instance state ... an association to an entity without loading its state from the database . The application should not

;  Object entity ,    String attributeName ) Load the persistent value of a given ... instance Throws: IllegalArgumentException - if the given object is not an instance of an entity class ... with an open persistence context or cannot be loaded from the database . Since: Jakarta Persistence (JPA) 3.2

;  Object entity ) Load the persistent state of an entity belonging to the persistence unit ... : IllegalArgumentException - if the given object is not an instance of an entity class belonging ... or cannot be loaded from the database . Since: Jakarta Persistence (JPA) 3.2

(    Object entity ,    Class entityClass ) Return true if the given entity ... instance Throws: IllegalArgumentException - if the given object is not an instance of an entity class ... or cannot be loaded from the database . Since: Jakarta Persistence (JPA) 3.2

Jakarta Persistence (JPA) Method in jakarta.persistence.TypedQuery TypedQuery setHint (    String hintName ,    Object value ) Set a query property or hint. The hints elements ... on the database in use and the locking mechanisms used by the provider, this hint may or may not be observed

Jakarta Persistence (JPA) Method in jakarta.persistence.EntityManager void detach (    Object entity ) Evict the given managed or removed entity from the persistence context, causing ... deletion of the entity, will never be synchronized to the database . Managed entities which reference

Jakarta Persistence (JPA) Method in jakarta.persistence.StoredProcedureQuery StoredProcedureQuery setHint (    String hintName ,    Object value ) Set a query property or hint ... . Depending on the database in use, this hint may or may not be observed. Parameters: value - value

The Java Data Objects (JDO) is another standard for accessing persistent data in databases , using ... with both relational and object databases . JDO is supported by many object databases , including ObjectDB, and it is probably the most popular Java API for object databases today.