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by ori_b 1086 days ago
Do you have benchmarks of lmdb when the working set is much larger than memory? I couldn't find any.

In my experience -- and in line with the article -- mmap works fine with small working sets. It seems that most benchmarks of lmdb have relatively small data sets.
1 comments
hyc_symas 1086 days ago
> Do you have benchmarks of lmdb when the working set is much larger than memory? I couldn't find any.

Where did you look? This is a sample using DB 5x and 50x larger than RAM http://www.lmdb.tech/bench/hyperdex/

There are plenty of other larger-than-RAM benchmarks there.

link
ori_b 1086 days ago
Hm. That seems to be comparing against a 2013 era leveldb, which at the time also used mmap. (It's since switched the default for performance reasons)

It's also strange to me that there's no transition in performance when the data set size grows beyond cache.

link