Database owners can issue the checkpoint command to force all modified pages in memory to be written to disk. Manual checkpoints do not truncate the log, even if the trunc log on chkpt option of sp_dboption is turned on.
Use the checkpoint command:
As a precautionary measure in special circumstances—for example, just before a planned shutdown with nowait so that Adaptive Server recovery mechanisms occur within the recovery interval. (An ordinary shutdown performs a checkpoint.)
To cause a change in database options to take effect after executing sp_dboption. (After you run sp_dboption, an informational message reminds you to run checkpoint.)
You can use checkpoint to identify the one or more databasess or use an all clause.
checkpoint [all | [dbname[, dbname[, dbname.....]]]
