PostgreSQL 11 → 12 GUC diff

Core configuration parameters added, removed, or changed in boot default between PostgreSQL 11 and 12.

Note

Fact. The measured inventory changes from 292 to 317 settings: 26 added, 6 boot-default changes, and 1 removed.

Added parameters

Parameter	Type	Context	Boot default	Category
`archive_cleanup_command`	`string`	`sighup`	`""` (empty string)	Write-Ahead Log / Archive Recovery
`default_table_access_method`	`string`	`user`	`heap`	Client Connection Defaults / Statement Behavior
`log_transaction_sample_rate`	`real`	`superuser`	`0`	Reporting and Logging / When to Log
`plan_cache_mode`	`enum`	`user`	`auto`	Query Tuning / Other Planner Options
`primary_conninfo`	`string`	`postmaster`	`""` (empty string)	Replication / Standby Servers
`primary_slot_name`	`string`	`postmaster`	`""` (empty string)	Replication / Standby Servers
`promote_trigger_file`	`string`	`sighup`	`""` (empty string)	Replication / Standby Servers
`recovery_end_command`	`string`	`sighup`	`""` (empty string)	Write-Ahead Log / Archive Recovery
`recovery_min_apply_delay`	`integer`	`sighup`	`0 ms`	Replication / Standby Servers
`recovery_target`	`string`	`postmaster`	`""` (empty string)	Write-Ahead Log / Recovery Target
`recovery_target_action`	`enum`	`postmaster`	`pause`	Write-Ahead Log / Recovery Target
`recovery_target_inclusive`	`bool`	`postmaster`	`on`	Write-Ahead Log / Recovery Target
`recovery_target_lsn`	`string`	`postmaster`	`""` (empty string)	Write-Ahead Log / Recovery Target
`recovery_target_name`	`string`	`postmaster`	`""` (empty string)	Write-Ahead Log / Recovery Target
`recovery_target_time`	`string`	`postmaster`	`""` (empty string)	Write-Ahead Log / Recovery Target
`recovery_target_timeline`	`string`	`postmaster`	`latest`	Write-Ahead Log / Recovery Target
`recovery_target_xid`	`string`	`postmaster`	`""` (empty string)	Write-Ahead Log / Recovery Target
`restore_command`	`string`	`postmaster`	`""` (empty string)	Write-Ahead Log / Archive Recovery
`restrict_nonsystem_relation_kind`	`string`	`user`	`""` (empty string)	Client Connection Defaults / Statement Behavior
`shared_memory_type`	`enum`	`postmaster`	`mmap`	Resource Usage / Memory
`ssl_library`	`string`	`internal`	`OpenSSL`	Preset Options
`ssl_max_protocol_version`	`enum`	`sighup`	`""` (empty string)	Connections and Authentication / SSL
`ssl_min_protocol_version`	`enum`	`sighup`	`TLSv1`	Connections and Authentication / SSL
`tcp_user_timeout`	`integer`	`user`	`0 ms`	Client Connection Defaults / Other Defaults
`wal_init_zero`	`bool`	`superuser`	`on`	Write-Ahead Log / Settings
`wal_recycle`	`bool`	`superuser`	`on`	Write-Ahead Log / Settings

Boot-default changes

Parameter	PG11	PG12	Category
`autovacuum_vacuum_cost_delay`	`20 ms`	`2 ms`	Autovacuum
`extra_float_digits`	`0`	`1`	Client Connection Defaults / Locale and Formatting
`jit`	`off`	`on`	Query Tuning / Other Planner Options
`server_version`	`11.22 (Debian 11.22-1.pgdg120+1)`	`12.22 (Debian 12.22-1.pgdg120+1)`	Preset Options
`server_version_num`	`110022`	`120022`	Preset Options
`transaction_isolation`	`default`	`read committed`	Client Connection Defaults / Statement Behavior

Removed parameters

Parameter	Last type	Context	Last boot default	Category
`default_with_oids`	`bool`	`user`	`off`	Version and Platform Compatibility / Previous PostgreSQL Versions

Method

The three lists compare the pinned PG11 and PG12 pg_settings snapshots directly. A default change is a change in the boot_val plus unit pair; setting is excluded so an initdb-generated value is not mistaken for the compiled boot default.