Mastering PostgreSQL 12 - Third Edition

Tracking the background worker

In this section, we will take a look at the background writer statistics. As you may already know, database connections will, in many cases, not write blocks to disks directly. Instead, data is written by the background writer process or by the checkpointer.

To see how data is written, inspect the pg_stat_bgwriter view:

test=# \d pg_stat_bgwriter                          View "pg_catalog.pg_stat_bgwriter"        Column         |           Type           | Collation | Nullable | Default -----------------------+--------------------------+-----------+----------+--------- checkpoints_timed     | bigint                   |           |          |  checkpoints_req       | bigint                   |           |          |  checkpoint_write_time | double precision         |           |          |  checkpoint_sync_time  | double precision         |           |          |  buffers_checkpoint    | bigint                   |           |          |  buffers_clean ...