摘要:
1.EXPLAIN EXTENDED SELECT NAME,ACCOUNT from PLAYER_INFO where NAME in (SELECT NAME from PLAYER_INFO group by NAME having count(NAME)>1); 2.EXPLAIN EXT 阅读全文
摘要:
转自:http://www.cnblogs.com/sunyubo/archive/2010/12/24/2282078.html 1. I/O模型 Unix下共有五种I/O模型 a. 阻塞I/O b. 非阻塞I/O c. I/O复用(select和poll) d. 信号驱动I/O(SIGIO) e 阅读全文