Difference between the SQL Server CHECKPOINT and Lazy Writer
Let’s have a quick summary to see the difference between the CHECKPOINT and the Lazy Writer process.
CHECKPOINT | LAZY WRITER |
SQL Server uses CHECKPOINT to flush dirty pages in the disk to keep database recovery as per the defined threshold. check | SQL Server uses the Lazy Writer process to flush the dirty and clean pages for keeping free space in the buffer cache to accommodate new pages |
CHECKPOINT generates the transaction log records and follows the write-ahead logging process | A lazy writer does not make any entry in the transaction log |
CHECKPOINT flushes only the dirty pages | It flushes both dirty and clean pages |
We can manually execute the CHECKPOINT or control the CHECKPOINT behavior by setting the appropriate parameters | DBA cannot control on the Lazy Writer process |
CHECKPOINT is also dependent on the recovery model | Lazy Writer does not have any relationship with the database recovery model |
We can monitor the CHECKPOINT event by using the undocumented system function as well as the trace flags. Starting from SQL Server 2012, it also logs an entry in the error log for the long CHECKPOINT | We cannot monitor the Lazy Writer process |
We can check CHECKPOINT LSN in the database boot page | We cannot check the Lazy writer process |
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