Type: real
Default: 0.9
Min: 0
Max: 1
Context: sighup
Restart: false

Specifies the target of checkpoint completion, as a fraction of total time between checkpoints. The default is 0.9, which spreads the checkpoint across almost all of the available interval, providing fairly consistent I/O load while also leaving some time for checkpoint completion overhead. Reducing this parameter is not recommended because it causes the checkpoint to complete faster. This results in a higher rate of I/O during the checkpoint followed by a period of less I/O between the checkpoint completion and the next scheduled checkpoint. This parameter can only be set in the postgresql.conf file or on the server command line.


Defines the fraction of one checkpoint_interval over which to spread checkpoints. The default value works for most users.