PG_STAT_BGWRITER

PG_STAT_BGWRITER showing statistics about the background writer process's activity.

Table 1 PG_STAT_BGWRITER columns

Name	Type	Description
checkpoints_timed	bigint	Number of scheduled checkpoints that have been performed
checkpoints_req	bigint	Number of requested checkpoints that have been performed
checkpoint_write_time	double precision	Total time that has been spent in the portion of checkpoint processing where files are written to disk (unit: ms)
checkpoint_sync_time	double precision	Total time that has been spent in the portion of checkpoint processing where files are synchronized to disk (unit: ms)
buffers_checkpoint	bigint	Number of buffers written during checkpoints
buffers_clean	bigint	Number of buffers written by the background writer
maxwritten_clean	bigint	Number of times the background writer stopped a cleaning scan because it had written too many buffers
buffers_backend	bigint	Number of buffers written directly by a backend
buffers_backend_fsync	bigint	Number of times a backend had to execute its own fsync call (normally the background writer handles those even when the backend does its own write)
buffers_alloc	bigint	Number of buffers allocated
stats_reset	timestamp with time zone	Time at which these statistics were last reset