MySQL崩溃错误：Out of memory (Needed 1073741816 bytes)

大多数人认为MySQL的最大内存占用大小的公式是这样的：

Maximum MySQL Memory Usage = innodb_buffer_pool_size + key_buffer_size + (read_buffer_size + sort_buffer_size) X max_connections

但是我更倾向于这种：

Maximum MySQL Memory Usage = innodb_buffer_pool_size + key_buffer_size + ((read_buffer_size + read_rnd_buffer_size + sort_buffer_size + join_buffer_size) X max_connections)

这些变量导入公式后的总和不要超过物理内存的80%：

sort_buffer_size

read_buffer_size

read_rnd_buffer_size

join_buffer_size

max_connections

原文：http://dba.stackexchange.com/questions/1927/why-does-mysql-say-im-out-of-memory