Relevant: Concurrent on-disk btree https://code.google.com/p/high-concurrency-btree/ https://code.google.com/p/high-concurrency-btree/ "Lehman and Yao's high

Relevant: Concurrent on-disk btree https://code.google.com/p/high-concurrency-btree/ https://code.google.com/p/high-concurrency-btree/ "Lehman and Yao's high concurrency B-Tree in C language with Jaluta's balanced B-link tree operations including a locking enhancement for increased concurrency"