X$BH State列:
Buffer Cache 中所有块的当前状态
从State列可得到缓冲区状态值表:
0,'free' 空闲
1,'xcur' 独占
2,'scur' 并发共享
3,'cr' 一致性读取
4,'read' 读取
5,'mrec' MediaRecovery
6,'irec' InstanceRecovery
7,'write' 写入
8,'pi', Pinned
9,'memory' 内存
10,'mwrite' 内存写
11,'donated'
0, FREE, no valid block image
1, XCUR, a current mode block, exclusive to this instance
2, SCUR, a current mode block, shared with other instances
3, CR, a consistent read (stale) block image
4, READ, buffer is reserved for a block being read from disk
5, MREC, a block in media recovery mode
6, IREC, a block in instance (crash) recovery mode
1, XCUR, a current mode block, exclusive to this instance
2, SCUR, a current mode block, shared with other instances
3, CR, a consistent read (stale) block image
4, READ, buffer is reserved for a block being read from disk
5, MREC, a block in media recovery mode
6, IREC, a block in instance (crash) recovery mode
This is a very useful internal view on the buffer cache headers for database blocks in the buffer cache, V$BH.
V$BH 来源于X$BH与X$LE
来自 “ ITPUB博客 ” ，链接：https://blog.itpub.net/22990797/viewspace-753138/ ，如需转载，请注明出处，否则将追究法律责任。
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