Physical Logging during partition extend: Number of bit map pages to be logged i

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Technote (FAQ)

Question
What means messages like this in online.log ?

00:31:45 Physical Logging during partition extend: Number of bit map pages to be logged in critcal section: 51 Remaining Phyical Log: 1762220
Cause
Load data into tables
Answer
We have a situation where we are allocating a large extent. The large extent allocates many bitmap pages. All these have to be physically logged and when we do that we are in a critical section. If we are in a critical section, check points have to wait. In that case, we just make sure we have enough physical log. In this case, there is plenty of physical log.

A critical section is just a transaction that does INSERT/UPDATE/DELETE or does explicit or implicit DDL grabbing extra extents. To extend a partition(read table) is one of those implicit ddl's.