D
Dapeng Wu
Guest
George, I think you got most of the calculation right. One thing I want to point out is that in Redo Phase, not all the block updates will turn into actual writes. A block may be updated many times but only with one or even no writes. During the Redo phase, we only replay the notes from the BI. This means no BI writes in this phase. So your calculation of 66 block/sec is actually from BI reads. When recovery moves to Physical/Logical undo phase, then BI activity will involve writes because we need to record the (new) actions to roll back uncommitted transactions. Your understanding of the Logical undo phase is also correct. You can't use the block number/offsets to calculate the number of BI blocks, as BI blocks are grouped into clusters, but clusters may be out of order. Dapeng
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