Bitcoin full node and query server

Nov 5, 2024

View in context in the libbitcoin Slack #general mirror.

somewhat unrelated, im very curious what insights you guys have regarding mmap'd db architectures. ive been exploring mdbx as a replacement for leveldb in core as sort of a moonshot side experiment, and mdbx (fork of lmdb) is essentially a mmap'd shadow paged btree. we saw some really promising benchmarks, but also a ton of write amplification. curious if you guys have any insights, since it seems you've rolled your own mmaped db architecture?

evoskuil19:28

I would absolutely not recommend it for use in any general purpose database. mmap must page to get/set any amount of data. Data locality and access patterns become a significant consideration, pretty much dominating everything else. These are not generally encountered under you start operating under heavy stress, so it can look great until you get into thrashing and then it goes parabolic.

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