摘要:
http://blog.csdn.net/luowangjun/article/details/4866084http://konglx.iteye.com/blog/1873805 阅读全文
摘要:
1. 监控事例的等待select event,sum(decode(wait_Time,0,0,1)) "Prev",sum(decode(wait_Time,0,1,0)) "Curr",count(*) "Tot"from v$session_Waitgroup by event order b... 阅读全文
摘要:
1.--查看表锁SELECT*FROMSYS.V_$SQLAREAWHEREDISK_READS>100; 2.--监控事例的等待SELECTEVENT, SUM(DECODE(WAIT_TIME,0,0,1))"Prev", SUM(DECODE(WAIT_TIME,0,1,0))"Curr", ... 阅读全文
摘要:
表级锁共具有五种模式,如下所示。行级排他锁(Row Exclusive,简称RX锁)当我们进行DML时会自动在被更新的表上添加RX锁,或者也可以通过执行lock命令显式的在表上添加RX锁。在该锁定模式下,允许其他的事务通过DML语句修改相同表里的其他数据行,或通过lock命令对相同表添加RX锁定,但... 阅读全文