doc: update bgwriter description
authorBruce Momjian <bruce@momjian.us>
Mon, 16 Nov 2020 18:13:43 +0000 (13:13 -0500)
committerBruce Momjian <bruce@momjian.us>
Mon, 16 Nov 2020 18:13:43 +0000 (13:13 -0500)
commit62b50ad698f8a789f92177ad72639f99d94d7d78
tree57921fb6c14031f85af323dcf2ad974de7a46641
parent8ad06bcbe136360296a804da7d7631a78fd15e70
doc:  update bgwriter description

This clarifies exactly what the bgwriter does, which should help with
tuning.

Reported-by: Chris Wilson
Discussion: https://postgr.es/m/160399562040.7809.7335281028960123489@wrigleys.postgresql.org

Backpatch-through: 9.5
doc/src/sgml/config.sgml