Off-heap Vs On-Heap Lookup cache issue #3663

Hey,

Issue #3663 says

“it was supposed that MapDB caches 10 millions of bytes (see https://github.com/druid-io/druid/blob/420358029061acb09e5f40370881f88e5a36d8d5/docs/content/development/extensions-core/lookups-cached-global.md, search “10MB” in page), but actually MapDB caches 10 millions entries (check the MapDB source code).”

But I have a few lookups having even 16 million entries.

If I use “onHeap” then the entire lookup will be stored in heap but if I use “offHeap” then 10 million entries will be stored in Heap and rest will be memory-mapped files???

Correct me if I’m wrong somewhere.

Please mark me in the thread if this is a duplicate post.

Thanks!!