在SG中看redo log buffer时有这么一段:
It records the block that is changed,the location of the change,and the new value in a redo entry.A redo entry makes no distinction between the type of block that is changed; it simply records which bytes are changed in the block.
在rollback segment中有:
changes to rollback segments are recorded in the redo log buffer.
我想知道,系统怎么知道哪条记录是undo条目,哪条记录是redo条目?
