What is the difference between a lock and a latch in the context of concurrent access to a database?

Question

I am trying to understand a paper on concurrent B-tree, in which the author mentioned latch vs lock, and how latches do not need a \"Lock Manager\". I have been trying to figure

Answer 1

It really depends on your DBMS, but here's a good explanation for Oracle.

http://www.dba-oracle.com/t_lru_latches.htm

Latches are like locks for RAM memory structures to prevent concurrent access and ensure serial execution of kernel code. The LRU (least recently used) latches are used when seeking, adding, or removing a buffer from the buffer cache, an action that can only be done by one process at a time.