For anyone else that experiences similar memory problems - it was found out that this was not exactly a memory leak, but in some cases ObjectDB memory consumption might be just too high, and this can be fixed by setting the configuration.
The following configuration elements are particularly relevant:
- The <processing> element - try reducing the number of threads and the cache size (notice that this setting is per open database, so this is especially important for applications that use many open databases).
- The <temp> element - try reducing the threshold, e.g. from 64MB to 8MB (notice that this setting is per value list, and each transaction or query execution could use several values lists, so high database activity may lead to using many value lists of up to 64MB each, when the default configuration is used).
In addition, if the problem is caused by heavy queries - defining new indexes (but see this issue) may help.
ObjectDB - Fast Object Database for Java (JPA/JDO)