开发文档Use the smallest integer data type for the AUTO_INCREMENT column that is large enough to hold the maximum sequence value you will need. When the column reaches the upper limit of the data type, the next attempt to generate a sequence number fails. Use the UNSIGNED attribute if possible to allow a greater range.
maximum sequence value you will need. When the column reaches the upper limit of the data type, the
next attempt to generate a sequence number fails. Use the UNSIGNED attribute if possible to allow a
greater range.
参考下:innodb_autoinc_lock_mode
内存上的一个mutex非常轻量级