from our readme:
The unfairly fast nostr database backed by lmdb.
nostrdb stores nostr events as a custom in-memory representation that enables zero-copy and O(1) access to all note fields. This is similar to flatbuffers but it is custom built for nostr events.
These events are then memory-mapped inside lmdb, enabling insanely fast, zero-copy access and querying.
This entire design of nostrdb is copied almost entirely from strfry, the fastest nostr relay. The difference is that nostrdb is meant to be embeddable as a C library into any application with full nostr query support.