Updated on 2023-10-23 GMT+08:00

BGWRITER_STAT

BGWRITER_STAT displays statistics about the background writer process's activities.

Table 1 BGWRITER_STAT 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 the backend

buffers_backend_fsync

bigint

Number of times the 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