[MySQL友情协助]ERROR3(HY000):Errorwritingfile'/d_MySQL:bitsCN.com 朋友线上DB执行SQL报错：ERROR 3 (HY000): Error writing file '/dev/shm/MYHTwgxT' (Errcode: 28) 让朋友取得dev组run 过的sql，执行explain，如下：mysql> explainselect count(*) from (