WHERE col1=val1 AND col2=val2;index exists on col1 and col2, the appropriate rows can be fetched directly
摘要:
http://www.jianblog.com/2006/07/10/70/ Suppose that you issue the following SELECT statement: mysql> SELECT * FROM tbl_name WHERE col1=val1 AND col2=val2; If a multiple-column index exists on col1 ... 阅读全文
posted @ 2008-11-05 22:02 cy163 阅读(634) 评论(0) 推荐(0) 编辑