摘要: 一.DB(Data block) From:http://www.orafaq.com/wiki/Data_block A data block is the smallest unit of storage in an Oracle database. Every database has a default block size (specified when the database is created), although blocks in different tablespaces may have different block sizes. An extent cons... 阅读全文
posted @ 2013-04-23 15:12 taowang2016 阅读(819) 评论(2) 推荐(0) 编辑
摘要: http://blog.csdn.net/tianlesoftware/article/details/7777511一.RAC全局等待事件说明在RAC环境中,和全局调整缓存相关的最常见的等待事件是global cache cr request,global cache busy和equeue。当一个进程访问需要一个或者多个块时,Oracle会首先检查自己的Cache是否存在该块,如果发现没有,就会先通过global cache赋予这些块共享访问的权限,然后再访问。假如,通过global cache发现这些块已经在另一个实例的Cache里面,那么这些块就会通过Cache Fusion,在节点之 阅读全文
posted @ 2013-04-23 11:38 taowang2016 阅读(1362) 评论(0) 推荐(0) 编辑
摘要: https://blogs.oracle.com/askmaclean/entry/gc_buffer_busy_gcs_log?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+orana+%28OraNA%29http://t.askmaclean.com/thread-438-1-1.htmlgc current block busy 等待是RAC中global cache全局缓存当前块的争用等待事件, 该等待事件时长由三个部分组成:Time to process current block reques 阅读全文
posted @ 2013-04-23 10:58 taowang2016 阅读(740) 评论(0) 推荐(0) 编辑