0和2都是每秒從緩沖區(qū)寫入文件一次。區(qū)別是commit操作時，0不做任何操作，為2 的時候，commit時會把緩沖區(qū)內(nèi)容寫入文件。文檔上是這么寫的：If the value of innodb_flush_log_at_trx_commit is 0, the log buffer is written out to the log file once per second and the flush to disk operation is performed on the log file, but nothing is done at a transaction commit.. When the value is 2, the log buffer is written out to the file at each commit, but the flush to disk operation is not performed on it. However, the flushing on the log file takes place once per second also when the value is 2.