MINE Timestamp Is Less than APPLY Timestamp

Problem Description

We are a little bit confused with this case. Sometimes, our MINE timestamp is less than the APPLY timestamp:

--------------------------------------------------------------------------------------- MINE IS running. Currently at plog 2632 and SCN 15450971 (10/07/2014 15:50:36). APPLY IS running. Currently at plog 2636 and SCN 15454241 (10/07/2014 15:50:33).

Is this a normal process?

Solution

  1. After restart, APPLY can process already-done-work faster than MINE, so it can gain on it.

  2. Sometimes MINE does not advance the last obsolete redo. For example, when a chained row operation of a LOB operations straddles redo boundaries.

Arjen Visser October 11, 2014 20:38