About clear

forum_thread

First query takes 4+ minutes to complete

Hi, we are evaluating ObjectDB 2.5.1_04 in embedded mode hoping to replace SQLite in our application. We observed that in our case it takes on average more than 4 minutes to complete the first SELECT query that we run on the DB which contains about 320,000 records of a single type of object. SQLite in comparison responds within few seconds on average with the same number of records. We hope to receive your recommendation on how to improve this result with this post.   Test System ... the same behavior with the the following code (note, em.clear() at the start of the method, where em is an instance of an ... ( ) {   em. clear ( ) ; // TODO Remove me for production. Testing slow ...

 
issue

objectdb.home for client/server

Currently, we do need to manually setup the objectdb.home property eventhough we're working on client/server mode. However, without setting this in our client, he complains about the missing objectdb.conf. Why is this required? Can't the server deliver it? Most of the time we do not even know where our object db home is located at as we might have multiple server instances running on multiple machines so all we do really need to supply should be the server connection url and no objectdb.home..   Alex ... use the forum to discuss this - issue tracking is only for clear bugs and precisely described feature requests. ...

 
forum_thread

Garbage Free Persistence?

Hi, I am trying to make my application garbage free. I noticed ObjectDB is not garbage free - I noticed that by persisting the same object 1mio times - and I can see the java garbage collector kicking and the usedHeap increasing. Is there a way to persist entities in a garbage free manner? Thanks EKK ... doesn't usually improve performance. If you can show clear benefits in moving of ObjectDB to garbage free we may consider this is as ...

 
forum_thread

Understanding limitations of schema evolution

Hi, I am trying to understand the limitations of schema evolution and have read the material on http://www.objectdb.com/java/jpa/entity/schema as well as the link therein regarding manual schema update when changing a field’s name Yet, i am confused regarding how to handle the case where one re-factors a class by moving one if it's Fields to a different class. Is this case managable? Thanks... http://www.objectdb.com/java/jpa/setting/schema it is not clear how to handle this case. edit ...

 
forum_thread

Speed of queries that return many objects

Hi, I have a DB of 146MB - with 1_000_000 elements. Loading the contents (objectDB query in java) takes about 10sec. I am using a recent MacBook (SSD blabla - disk I/O speed is about 400MB/sec - according to blackMagicTest app for mac) - so I was expecting the query to take less than one sec (146/400 = 0.35sec.. + some overhead). I was wondering if this kind of speed is "normal", or if this is something I should investigate. Thanks EKK ... ) . commit ( ) ; em. clear ( ) ; } if ( ...

 
forum_thread

Like fails if both underscore and percent are used

When using a like query that has both _ and % in it, ObjectDB seems to fail. Here is a unit test to demonstrate:   ... Thank you for this report and for the clear test case. Please try build 2.5.4_03, which should fix this ...

 
forum_thread

Thread in BLOCKED state

Hello, Some on my threads stay in BLOCKED state in my thread pool. When i watch the stack trace, i see only just obfuscated object db code. ... The exact problem is not completely clear. A blocked thread is not necessarily a problem. There is an ...

 
forum_thread

Memory consumption of empty Strings

After doing some memory related research in my program, I found a possible place for an enhancement of objectdb: My program has several entities which contain many String. Often some of these String are empty (""). To avoid unnecessary memory consumption, the String within the entities are initialized like: String firstName = ""; ... . commit ( ) ; entityManager. clear ( ) ; }   entityManager. close ...

 
forum_thread

Problem with byte arrays in JDO - internal exception

This code generates an internal exception: ... ( ) ; // Clear out existing objects pm. currentTransaction ( ) ...

 
manual

Database Doctor

Explains how to use the ObjectDB object database Doctor tool to diagnose and repair database files and damaged Java/JPA/JDO objects.... computer virus). Given all these causes it is clear that database files should be backed up regularly and often. It is ...