Follow-up to the previous two commits: the ALTER DATABASE ... SET
autovacuum_* commands fail at boot with
ERROR: parameter "autovacuum_vacuum_scale_factor" cannot be changed now
and take matrix-synapse-db-tune.service (and nextcloud-db-init.service)
down with them.
Root cause: ALTER DATABASE/ROLE ... SET validates through
set_config_option() with an interactive context, and guc.c rejects any
PGC_SIGHUP parameter set that way. All autovacuum_* GUCs are
SIGHUP-context, so per-database scoping is impossible for them — only
USERSET-level parameters (e.g. work_mem, statement_timeout) can be set
per-database.
Nothing is lost: the same values are already set cluster-wide in
configuration.nix, which covers both nextclouddb and matrix-synapse.
Remove the ALTERs from nextcloud-db-init and delete the now-purposeless
matrix-synapse-db-tune service.
Sovran Contributor
8bc325b148