Clients often ask what the differences are between the various
InnoDB isolation levels, or what ACID means. Here are some simple
explanations for those that have not yet read the manual and
committed it to memory.
Every select operates without locks so you don’t get consistency
and might have dirt reads, which are potentially earlier versions
of data. So, no ACID support here.
Has consistent reads without locks. Each consistent read, even
within the same transaction, sets and reads its own fresh
The InnoDB default isolation level for ACID compliance. All reads
within the same transaction will be consistent between each other
– ie, the C in ACID. All writes will be durable, etc etc.
Same as REPEATABLE READ but MySQL converts regular select …