Tempdb Checkpoint

TempDB를 제외한 모든 DB들의 checkpoint는 주기적으로 진행된다. 여기서 checkpoint란 dirty page에 있는 정보들을 disk에 쓰는 행위를 말한다. 하지만, Tempdb의 경우 log의 70%까지 가득 차여야만 checkpoint를 실행한다.
  

The next most common condition that triggers a checkpoint is when the log becomes 70% full.

When a checkpoint occurs for a database in the SIMPLE recovery model, log clearing (a.k.a. log truncation) occurs. This means that some portions of the transaction log may be able to be marked as reusable if nothing else requires them to be kept around, thus decreasing the amount of space used in the log. (I'm vastly over-simplifying – see my article here for more details.)
 

원본 위치 <http://www.sqlmag.com/blog/sql-server-questions-answered-28/sql-server/when-do-checkpoints-occur-for-tempdb-137143>

   

*. Simple Recovery Type의 경우 Checkpoint는 두 가지 수치에 따라 결정
If the database is using the simple recovery model, an automatic checkpoint is generated whenever the number of log records reaches the lesser of these two values: 

• The log becomes 70 percent full.
• The number of log records reaches the number the Database Engine estimates it can process during the time specified in the recovery interval option.

원본 위치 <http://msdn.microsoft.com/en-us/library/ms189573(v=sql.90).aspx>
   

참고 링크
http://www.sqlmag.com/blog/sql-server-questions-answered-28/sql-server/when-do-checkpoints-occur-for-tempdb-137143
http://www.sqlskills.com/BLOGS/PAUL/post/How-do-checkpoints-work.aspx
http://www.sqlskills.com/blogs/paul/post/what-does-checkpoint-do-for-tempdb.aspx