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forum_thread

Database(*.odb) file size on disk

Hello, we have questions about the file size of ObjectDB database on disk. Can you tell us something about how the deleting of entities affects the size of *.odb files on disk? -Will the released memory always used by new entities? -Will be the database file automatically reduced?   We have created a small test, in which we create and delete entities. It looks like that the released memory are reused but the the file not resized. The database is at the end empty again, but larger than the initial size. #1 2016-07-15 10:06 Hello, we have questions about the file size of ObjectDB database on disk. Can you tell us something ...

 
forum_thread

Should derived fields of an EmbeddedId be manually maintained by app code?

If I have an Entity which has a primary key which is derived and I am implementing it using @EmbeddedId, am I responsible for maintaining the derived fields of the @EmbeddedId? I could not find anything in the JPA 2.0 spec http://download.oracle.com/auth/otn-pub/jcp/persistence-2.0-fr-oth-JSpec/persistence-2_0-final-spec.pdf?e=1317047713&h=54831c176e81a244a4c309e13eba0b27 which tells me what to expect. #1 2011-09-26 15:26 If I have an Entity which has a primary key which is derived and I am implementing it using @EmbeddedId, am I res ...

 
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Mapped By Fetch is very Slow

Well ! I think i pointed out a HUGE performance issue with mapped-by attribute (yeah again :( ). Here is the test case : 1- Create 100 000 entities with for each 1 entity with @OneToOne(mappedBy attribute) 2- Retrieve only 10 000 for testing 3- Wait ... On my AMD FX 8350, it took 60s Now, go the MyEntity class and remove "mapped-by". You obtain 1 second max of query fetch. #1 2015-06-19 11:05 Well ! I think i pointed out a HUGE performance issue with mapped-by attribute (yeah again :( ). Here is ...

 
forum_thread

Items in list are doubled, when the entity class is not enhanced

Dear all, I have a problem with adding items (entities) into other entity list. When the classes are not enhanced, added items are doubled. Here is an example: #1 2011-06-09 08:24 Dear all, I have a problem with adding items (entities) into other entity list. When the classes are not ...

 
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Some details about db behavior

Suppose I have two entities... A B -> A B has a ManyToOne relationship with A. When my database is empty and I persist a valid B entity (that contains actual A reference) I observe some behaviour that I'm not sure I understand. ... keeping copy of A? how do I achieve that when A is removed all objects referring to it will have null? I know that there ... as part of the B instance. When that A instance is removed you should also update the reference from B accordingly. Otherwise, ...

 
forum_thread

Schema Update: class hierarchy change

Hello, we try to change the class hierarchy of an Entity. You wrote www.objectdb.com/database/forum/899 that ObjectDB support automatic schema evolution for adding and removing fields and for class hierarchy change.   But our small test failed: At first create a DataBase with one Object of MyEntity ... Suppose we have a change, in which a class is removed from the hierarchy. How can we 'save' the contents of the fields from the class which was removed from the hierarchy. As Example: Given are the three ...

 
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Posting to ObjectDB Website - Important Instructions

Instructions for posting to ObjectDB website (to the forum, the issue tracking and the help desk). Please read the following instructions carefully - before posting to the ObjectDB website. 1. Where to Post Almost everything should be posted to the ObjectDB Forum  - and not as an help desk support ticket or as a ...

 
forum_thread

'DROP TABLE' in ODB?

Let's say I no longer need some entity in my project and after deleting all the objects of this type in database I want to remove this type from schema. How can I do this? Is there something like SQL 'drop table' in ODB? ... a feature on your roadmap that unused classes etc. can be removed from the DB? edit ...

 
forum_thread

Lazy loading does not work - crud takes long

tomee7.0.0SNAPSHOT,objectdb 2.6.4 The OneToMany Entities are filled with 40.000 Records and they have between 20-40 Columns. It takes over 50s to load all Project Enities that contains the OneToMany Relationships. It should be load lazy but i didnt know why the query fetch all the Data. #1 2015-10-24 23:07 tomee7.0.0SNAPSHOT,objectdb 2.6.4 The OneToMany Entities are filled with 40.000 Records and they have bet ...

 
api-jdo

removeFetchGroups(groups)

Remove the FetchGroups from the set of active FetchGroups.(Method of javax.jdo.PersistenceManagerFactory)