Hi

Woops... Amar, You caught my neck!

Well,

Step 1: Since there is Checkpoint during the logswitch then using other than current redo log file is ruled out. So restricting only to current redo log file.

Step 2. DBWR flushing dirty blocks to the data files, Oracle DOC:

The initialization parameter DB_WRITER_PROCESSES specifies the number of DBWn processes. If your system uses multiple DBWn processes, you should adjust the value of the DB_BLOCK_LRU_LATCHES parameter so that each DBWn process has the same number of latches (LRU buffer lists).The DBWn process writes dirty buffers to disk under the following conditions:

When a server process cannot find a clean reusable buffer after scanning a threshold number of buffers, it signals DBWn to write. DBWn writes dirty buffers to disk asynchronously while performing other processing.

DBWn periodically writes buffers to advance the checkpoint, which is the position in the redo thread (log) from which crash or instance recovery would need to begin. This log position is determined by the oldest dirty buffer in the buffer cache.
So it is clear that some of the RBS infomation must be flushed to the data files except the latest or complete. From that knowledge I concluded that it is taking PARTIAL of the current redo log file which is missing in the RBS

Amar, tell me me where I am wrong..?

I appreciate!


Regards

Thomas