InnoDB Transaction Model and Locking
InnoDB transaction model, the goal is to
combine the best properties of a multi-versioning database with
traditional two-phase locking.
locking on the row level and runs queries as non-locking
consistent reads by default, in the style of Oracle. The lock
InnoDB is stored so space-efficiently
that lock escalation is not needed: Typically several users are
allowed to lock every row in the database, or any random subset of
the rows, without
InnoDB running out of memory.