About result

forum_thread

Restrict by class in query

I have the following bit of code: ... the folder. I can, however do a .get(1) call to fetch the result. Am I doing something wrong to make sure that I only get folders in my result set? edit ...

 
forum_thread

performance limit

Hi, can someone share expirience with performance limits of ObjectDB especialy when quering tables with large records sets. Our issue is with tables with 100.000+ records. Everything was OK when we had few thousand records. We have a simple SELECT statement which selects from a table with 100.000+ records by UserID atribute, tables have from 5 to 20 atributes. Usualy the results range from few hundred to few thousand records. This query takes up to 12 seconds. Is this normal, what when we will have few milion records, how to handle this. ... runs much faster in the Explorer (because in the Explorer result data is always loaded lazily). You may execute queries in the application with lazy result loading, using the objectdb.result-fetch query's hint in order ...

 
release

2.6.8

... in queries. Fixed a bug in ordering query result by an expression that is used in IN operator. Fixed a ... ( issue #249 ). Improved title of query result windows in the Explorer. Changed the Enhancer to return ...

 
forum_thread

500Mb ObjectDb database opening issue

Hi, I have observed that 500 Mb objectDb database opening time is very slow (~3 seconds) for following code m_EntityMgrFactory = Persistence.createEntityManagerFactory( "objectdb:" + aFilename ); m_EntityManager = m_EntityMgrFactory.createEntityManager(); Does exist any way to speed-up open time for big databases? Definitely, it's too long for 500 Mb database! ... I removed all of them, but there is no differences in result With activation codes ~15 codes was observed 1/29/2016 ... all activation codes with enabled network I got successful result below 1/29/2016 19:33:10.3310: INFO : ...

 
api-jpa

orderBy(o)

Specify the ordering expressions that are used to order the query results.(Method of javax.persistence.criteria.CriteriaQuery)

 
api-jpa

javax.persistence.criteria.Fetch

Represents a join-fetched association or attribute.(Interface of JPA)

 
api-jpa

javax.persistence.criteria.FetchParent

Represents an element of the from clause which may function as the parent of Fetches.(Interface of JPA)

 
forum_thread

find() delay

Hi, I tried objectdb in following steps: 1, for 1 to 30 {trans.begin(); create typeC o; em.persist(o); trans.commit();} 2, for 1 to 30 {p = em.find(typeC.class, i); print(p)} So simple a test, there is no result in one go; I have to disable step 1 and run again, then Step 2 output the expected results. I tried em.flush(), em.clear(), etc.. that do not work. Any idea? TIA ... i); print(p)} So simple a test, there is no result in one go; I have to disable step 1 and run again, then Step 2 output ... runs twice in each test and choose only the second result, maybe is related to this. Institute of Computer ...

 
manual

Locking in JPA

Explains how to use optimistic locking and pessimistic locking in JPA.... when an pessimistic locking conflict occurs that does not result in transaction rollback. See JavaDoc Reference Page... is ... when an pessimistic locking conflict occurs that does not result in transaction rollback. See JavaDoc Reference Page... (on ...

 
api-jpa

javax.persistence.criteria.CompoundSelection

The CompoundSelection interface defines a compound selection item (tuple, array, or result of constructor).(Interface of JPA)