MapDB collection size issue

Question

I'm using MapDB 0.9-snapshot. I have some collection containing several millions of records String->String. My problem is that the method size() on such ConcurrentMap(s) takes a lot of time and a lot of memory (I have even an OutOfMemory error).

Any other experienced such a problem? Thanks Bye

score 2 · Accepted Answer · answered Mar 13 '13 at 17:32

2

MapDB needs to traverse all entries in collections to count it. You may store count in external Atomic.Long and retrieve it separately, an example is here:

https://github.com/jankotek/MapDB/blob/master/src/test/java/examples/Map_Size_Counter.java

OOEM should not happen, it is probably due to GC overhead assertion.

answered Mar 13 '13 at 17:32

Jan Kotek

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Thanks a lot Jan. It works. However, is quite strange to have it as external trick. – Brad Stallion Mar 14 '13 at 09:22
deadlink in the answer – Stepan Yakovenko Oct 22 '18 at 01:09

MapDB collection size issue

1 Answers1