How can I control cache of the DB4O

Question

I have some difficulties to find documents about DB4O. How can I control cache of the DB4O? I think than its connection is expending all memory of our server. I want set the minimal cache configuration. Could anyone recommend me some document or send me some examples?

I'm glad for anyone who can help.

score 1 · Accepted Answer · answered Jun 23 '19 at 17:56

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If you already made the cache configuration like @Gamlor said, the problem can be a object corrupted, you can delete this object and defrag your database to improve performance

answered Jun 23 '19 at 17:56

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This tecnology is too old, it's exactly what I made to solve it, then we change our database, but thank you. – Cleiton Capristano Jun 23 '19 at 18:00

score 0 · Answer 2 · answered Jul 18 '16 at 14:36

I would recommend looking at it with a profiler. Then you can see what kind of classes take up space.

A typical pitfall with db4o is that that a 'ObjectContainer' is kept open for a long time, with a high activation depth. Then a large part of your object graph is kept in memory.

Some nobs to try:

configuration.common().weakReferenceCollectionInterval(milli-secs);

How often db4o clears up it's weak reference cache system. If you lower that interval, cleans up more aggressive.

There is a file level cache. I think it's quite low by default. Anyway, here's setting:

Storage fileStorage = new FileStorage();
// A cache with 128 pages of 1024KB size, gives a 128KB cache
Storage cachingStorage = new CachingStorage(fileStorage,128,1024);
configuration.file().storage(cachingStorage);

Maybe there are more caches. I don't remember all of then.

How can I control cache of the DB4O

2 Answers2