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PostgreSQL Autotuning Knob Policy

This document records the inclusion/exclusion design decision for every knob in the PostgreSQL snapshot (397 total). It avoids implementation-centric framing and instead classifies knobs by optimization scope: performance optimization vs. semantics, security, topology, observability, and infrastructure policy.

See also: data/knob_policy.json (policy data) and src/knobs/policy.py (runtime loader and enforcement).

1. Policy intent and scope

What this tuner optimizes

The PBT tuner's objective is to maximize workload throughput and minimize query latency by searching the space of PostgreSQL runtime configuration parameters. The knob policy determines which parameters are admitted into that search space and which are excluded — and records the reasoning for every decision.

In scope

Parameters that directly influence workload execution efficiency:

  • Memory allocation (shared_buffers, work_mem, buffer pools)
  • Planner cost model (seq_page_cost, random_page_cost, cost weights)
  • Parallelism (max_parallel_workers, worker counts)
  • I/O behavior (effective_io_concurrency, bgwriter, checkpoint timing)
  • WAL and durability trade-offs (wal_level, fsync, synchronous_commit)
  • Autovacuum scheduling and resource limits

Out of scope

Parameters that define what the database is rather than how fast it runs:

  • Security policy (SSL/TLS, authentication, encryption)
  • Network topology (port, listen_addresses, replication connection strings)
  • File system paths and identity (data_directory, config_file, shared_preload_libraries)
  • Locale and formatting (TimeZone, DateStyle, lc_*)
  • Crash and recovery behavior (restart_after_crash, exit_on_error)
  • Audit/logging controls (logging_collector, log_destination, log_file_mode)
  • Debug/developer options (debug_print_plan, debug_discard_caches)
  • Data integrity bypass flags (zero_damaged_pages, ignore_checksum_failure)

2. Exclusion categories

Each exclusion is assigned a reason_code. The table below defines each code, its enforcement nature (absolute vs. conditional), and the conditions under which a knob in that category could be re-admitted.

Reason Code Description Nature Re-enable criteria
internal_context PostgreSQL context = internal parameters are read-only compile-time or memory-layout constants. No runtime interface can modify them. Absolute Cannot be re-enabled; inherently immutable.
applicator_dependency Disabling this knob would break the tuner's settings-application mechanism (ALTER SYSTEM). Absolute Cannot be re-enabled without replacing the settings applicator.
data_integrity Flags that bypass checksum validation or system index integrity. Enabling these in an automated loop risks silent data corruption across worker configurations. Absolute Never safe under automated tuning.
system_catalog_safety Permits direct writes to system catalog tables. Automating this risks internal catalog corruption. Absolute Never in an automated context.
debug_only Developer-mode flags with no production performance semantics. Absolute Not applicable to production optimization.
domain_scope_non_performance String parameters encoding identity, paths, locale, credentials, or recovery targets. They define operational configuration, not execution efficiency. (~70 parameters.) Absolute Not within this tuner's optimization objective.
semantic_behavior Flags that change SQL transactional semantics (default_transaction_read_only, default_transaction_deferrable). These alter the meaning of queries, not their speed. Absolute Not applicable.
network_binding port: modifies the postmaster listen port. Not a performance parameter; changes require restart and break benchmark connectivity. Absolute Not applicable.
network_discovery bonjour: Bonjour service advertisement. Unrelated to workload performance. Absolute Not applicable.
session_semantics Per-session transaction toggles (transaction_deferrable, transaction_read_only). Setting these globally via ALTER SYSTEM does not represent stable workload-wide optimization. Absolute Not applicable for global optimization.
security_transport SSL/TLS transport policy parameters. Security policy is external to the tuner's optimization objective. Conditional May be admitted in isolated research environments where SSL state is fixed and stable, via an explicit policy bypass.
benchmark_validity Parameters that introduce artificial latency (pre_auth_delay, post_auth_delay) or can cancel in-flight benchmark statements (statement_timeout). Conditional pre_auth_delay and post_auth_delay remain excluded. statement_timeout may be re-admitted if the evaluator manages its own per-step timeouts at each stage (partial admission implemented in Phase C for the VACUUM ANALYZE step).
mutual_exclusion Log statistics flags that are mutually exclusive at the PostgreSQL level. Enabling more than one subsystem flag at a time causes a configuration error. Conditional May be re-admitted if the tuner treats this group as a categorical single-select parameter and only ever activates one value at a time.
format_readback Octal-permission parameters (log_file_mode, unix_socket_permissions). PostgreSQL stores these as integers; the canonical form is octal, which the pipeline cannot reliably round-trip. Conditional Can be re-enabled once the pipeline handles octal encoding and validation for these specific parameters.
logging_pipeline_dependency logging_collector: redirects PostgreSQL log output away from stderr to managed files. The tuner's orchestration depends on stderr-based log collection. Conditional Can be re-enabled if the tuner's log collector is updated to read PostgreSQL-managed log files.
stability JIT compilation parameters (jit and family). JIT shows known instability in benchmark workloads in this environment: intermittent degradation and crashes under certain query patterns make benchmark scores unreliable. Conditional Can be re-enabled on PostgreSQL builds and environments where JIT is validated stable for the target workload (e.g., PG16+ OLAP with controlled query patterns).
os_alignment max_stack_depth must not exceed the OS ulimit -s stack size limit. The tuner cannot safely determine the correct OS-safe upper bound at runtime without reading /proc/1/limits or equivalent. Conditional Re-enable by adding OS stack limit discovery to the evaluator and clamping max_stack_depth at each worker startup.
storage_safety allow_in_place_tablespaces: enables tablespace creation in the PostgreSQL data directory path. Toggling in a tuning loop risks tablespace layout side effects. Conditional Can be re-enabled in controlled environments where tablespace layout is pre-fixed and verified.
uncurated_intmax_sentinel Numeric parameters whose PostgreSQL-native maximum is ≥ 2,000,000,000 (INT_MAX class) without curated metadata in data/knob_metadata.json defining practical bounds. The unbounded upper limit makes random search unsafe. Conditional Add a metadata entry in data/knob_metadata.json with practical tuning_min/tuning_max bounds and an impact_tier. The parameter is automatically promoted to the appropriate tier CSV on the next preprocessing run.

Sub-categories within domain_scope_non_performance

The domain_scope_non_performance code covers several distinct semantic groups:

Sub-group Examples ~Count
Paths and file locations data_directory, config_file, hba_file, ssl_cert_file 15
Identity and naming cluster_name, application_name, event_source 5
Locale and formatting TimeZone, DateStyle, lc_*, timezone_abbreviations 10
Replication topology primary_conninfo, recovery_target_*, synchronous_standby_names 10
Logging controls log_destination, log_directory, log_filename, log_line_prefix 7
Security credentials ssl_cert_file, ssl_key_file, ssl_ca_file, krb_server_keyfile 8
Library loading shared_preload_libraries, session_preload_libraries, local_preload_libraries 3
Misc operational search_path, temp_tablespaces, restrict_nonsystem_relation_kind 10

3. Source-stage classification rationale

Policy classification happens in retrieval.py::get_all_knobs_with_metadata(), which calls annotate_autotuning_policy() from src/knobs/policy.py before returning. This adds three columns to every row of the 397-knob dataframe:

Column Type Meaning
eligible_for_autotuning bool True if the knob is admitted to the optimization search space
autotuning_exclusion_reason_code str Category code from §2 (empty string for admitted knobs)
autotuning_exclusion_reason_detail str Human-readable exclusion reason (empty string for admitted knobs)

Downstream preprocessing reads eligible_for_autotuning and defines no additional policy of its own. A separate bounds safety gate (apply_bounds_safety_gate()) excludes uncurated INT_MAX-sentinel knobs as a second pass over the already-annotated dataframe.

Benefits of source-stage classification

  • Single authority. data/knob_policy.json is the policy source of truth; src/knobs/policy.py loads and enforces it.
  • Full auditability. The complete 397-row annotated dataframe is available for dashboards, reports, and tests.
  • Structured logging. The pipeline logs a grouped breakdown of excluded knobs by reason code at each run.
  • Safe re-enablement. Adding or removing a policy entry requires a change to exactly one JSON map in one file.

4. Operational guidance

Adding a new exclusion

  1. Look up the knob name as it appears in pg_settings.name.
  2. Select the appropriate reason_code from the table in §2.
  3. Add an entry to AUTOTUNING_SOURCE_EXCLUSIONS in data/knob_policy.json:
"AUTOTUNING_SOURCE_EXCLUSIONS": {
  "knob_name": [
    "reason_code",
    "One sentence explaining why this knob is excluded."
  ]
}
  1. Update the knob's row in the full inventory below: set Decision to Exclude, and fill in the Reason Code and Reason columns.
  2. Run the preprocessing pipeline and confirm the exclusion count increases by 1:
python -m src.knobs.preprocess_knobs data/postgresql_all_knobs_demo.csv
  1. Run the unit tests: pytest tests/unit/knobs/.

Removing an exclusion (re-admitting a knob)

  1. Find the knob entry in AUTOTUNING_SOURCE_EXCLUSIONS inside data/knob_policy.json.
  2. Verify all re-enable conditions for its reason_code (§2) are satisfied.
  3. Delete the entry from AUTOTUNING_SOURCE_EXCLUSIONS.
  4. If the knob's native max is ≥ 2,000,000,000, also add a metadata entry in data/knob_metadata.json (see below).
  5. Run the preprocessing pipeline and confirm the knob appears in the expected tier CSV.
  6. Update the inventory row to Include and set the appropriate Reason Code.
  7. Run the unit tests: pytest tests/unit/knobs/.

Promoting an uncurated_intmax_sentinel knob

The most common re-admission path. Most INT_MAX-sentinel knobs are excluded purely by the bounds safety gate, not by an AUTOTUNING_SOURCE_EXCLUSIONS entry. To promote one:

  1. Research practical operating bounds in the PostgreSQL documentation and community tuning guides.
  2. Add a knob metadata entry in data/knob_metadata.json:
"knob_name": {
  "tuning_min": <practical_min>,
  "tuning_max": <practical_max>,
  "scale": "linear",
  "impact_tier": "extensive",
  "tuning_priority": 5,
  "notes": "What this knob controls.",
  "hardware_relative": false,
  "resource_type": ""
}
  1. Run the pipeline: the knob is automatically promoted to the correct tier CSV.
  2. Verify metadata loads and preprocessing runs without exclusions regressions.

Changing a reason code

If a knob's exclusion reason is reclassified (e.g., stability → benchmark_validity):

  1. Update the AUTOTUNING_SOURCE_EXCLUSIONS entry in data/knob_policy.json.
  2. Update the knob's row in the inventory table below.
  3. Run the pipeline and unit tests.

Version upgrade: handling new knobs

When upgrading to a new PostgreSQL minor or major version, run the preprocessing pipeline and inspect the log output for any new knobs appearing without a policy exclusion annotation that may represent out-of-scope parameters. Add entries to AUTOTUNING_SOURCE_EXCLUSIONS in data/knob_policy.json as needed before merging.

5. Full knob decision inventory

Columns:

  • Min/Max: Curated bounds for curated knobs; native pg_settings bounds otherwise.
  • Decision: Include or Exclude.
  • Reason Code / Reason: Clear rationale category and detail.
Knob Min Max Unit Vartype Context Decision Reason Code Reason
DateStyle — — — string user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
IntervalStyle — — — enum user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
TimeZone — — — string user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
allow_alter_system — — — bool sighup Exclude applicator_dependency Tuner applies settings via ALTER SYSTEM; disabling this breaks configuration application.
allow_in_place_tablespaces — — — bool superuser Exclude storage_safety Storage/path behavior option; excluded from autotuning safety policy.
allow_system_table_mods — — — bool superuser Exclude system_catalog_safety System catalog mutation option; excluded from autotuning safety policy.
application_name — — — string user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
archive_cleanup_command — — — string sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
archive_command — — — string sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
archive_library — — — string sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
archive_mode — — — enum postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
archive_timeout 0.0 1073741823.0 s integer sighup Exclude benchmark_validity WAL archiving timer; not relevant as benchmarks don't measure archiving latency.
array_nulls — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
authentication_timeout 1.0 600.0 s integer sighup Exclude benchmark_validity Login timeout setting; not a workload performance tuning knob.
autovacuum — — — bool sighup Include admitted_curated Enable autovacuum. Usually keep on.
autovacuum_analyze_scale_factor 0.01 0.5 — real sighup Include admitted_curated fraction of table modified for analyze.
autovacuum_analyze_threshold 0.0 2147483647.0 — integer sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
autovacuum_freeze_max_age 100000.0 2000000000.0 — integer postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
autovacuum_max_workers 1 8 — integer sighup Include admitted_curated Max autovacuum worker processes.
autovacuum_multixact_freeze_max_age 10000.0 2000000000.0 — integer postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
autovacuum_naptime 1 600 s integer sighup Include admitted_curated Time between autovacuum runs.
autovacuum_vacuum_cost_delay -1.0 50.0 ms real sighup Include admitted_curated ms delay after cost limit is hit.
autovacuum_vacuum_cost_limit -1 2000 — integer sighup Include admitted_curated per-worker autovacuum cost limit.
autovacuum_vacuum_insert_scale_factor 0.01 0.5 — real sighup Include admitted_curated fraction of table inserted for vacuum.
autovacuum_vacuum_insert_threshold -1.0 2147483647.0 — integer sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
autovacuum_vacuum_max_threshold -1.0 2147483647.0 — integer sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
autovacuum_vacuum_scale_factor 0.01 0.5 — real sighup Include admitted_curated fraction of table modified for vacuum.
autovacuum_vacuum_threshold 0.0 2147483647.0 — integer sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
autovacuum_work_mem -1.0 2147483647.0 kB integer sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
autovacuum_worker_slots 1 16 — integer postmaster Include admitted_curated Autovacuum worker slot capacity; aligned with practical worker process limits.
backend_flush_after 0 256 8kB integer user Include admitted_curated pages written by backend before OS flush.
backslash_quote — — — enum user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
backtrace_functions — — — string superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
bgwriter_delay 10 2000 ms integer sighup Include admitted_curated ms between bgwriter rounds.
bgwriter_flush_after 0 256 8kB integer sighup Include admitted_curated pages written by bgwriter before OS flush.
bgwriter_lru_maxpages 0 1000 — integer sighup Include admitted_curated pages per bgwriter round.
bgwriter_lru_multiplier 0.0 10.0 — real sighup Include admitted_curated multiplier for pages to write based on recent usage.
block_size 8192.0 8192.0 — integer internal Exclude internal_context Internal parameters cannot be modified via PostgreSQL runtime/config interfaces.
bonjour — — — bool postmaster Exclude network_discovery Service discovery/network behavior, not performance tuning.
bonjour_name — — — string postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
bytea_output — — — enum user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
check_function_bodies — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
checkpoint_completion_target 0.1 0.9 — real sighup Include admitted_curated Spread checkpoint I/O over this fraction of checkpoint_timeout.
checkpoint_flush_after 0 256 8kB integer sighup Include admitted_curated pages written by checkpointer before OS flush.
checkpoint_timeout 30 3600 s integer sighup Include admitted_curated Max time between automatic checkpoints. Affects recovery time.
checkpoint_warning 0.0 2147483647.0 s integer sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
client_connection_check_interval 0.0 2147483647.0 ms integer user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
client_encoding — — — string user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
client_min_messages — — — enum user Exclude benchmark_validity Low message-level settings can alter runtime overhead and benchmark comparability.
cluster_name — — — string postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
commit_delay 0 10000 — integer superuser Include admitted_curated microseconds to wait for group commit.
commit_siblings 0 20 — integer user Include admitted_curated concurrent active transactions to trigger commit_delay.
commit_timestamp_buffers 0 1024 8kB integer postmaster Include admitted_curated SLRU buffers for commit timestamps (must be multiple of 16).
compute_query_id — — — enum superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
config_file — — — string postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
constraint_exclusion — — — enum user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
cpu_index_tuple_cost 0.0001 0.01 — real user Include admitted_curated Cost of processing each index entry.
cpu_operator_cost 0.0001 0.01 — real user Include admitted_curated Cost of executing operators/functions.
cpu_tuple_cost 0.001 0.1 — real user Include admitted_curated Cost of processing each row.
createrole_self_grant — — — string user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
cursor_tuple_fraction 0.0 1.0 — real user Include admitted_curated planner estimator for cursor retrieval fraction.
data_checksums — — — bool internal Exclude internal_context Internal parameters cannot be modified via PostgreSQL runtime/config interfaces.
data_directory — — — string postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
data_directory_mode 0.0 511.0 — integer internal Exclude internal_context Internal parameters cannot be modified via PostgreSQL runtime/config interfaces.
data_sync_retry — — — bool postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
deadlock_timeout 1.0 2147483647.0 ms integer superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
debug_assertions — — — bool internal Exclude internal_context Internal parameters cannot be modified via PostgreSQL runtime/config interfaces.
debug_discard_caches 0.0 0.0 — integer superuser Exclude debug_only Debug/developer option; not valid for production workload tuning.
debug_io_direct — — — string postmaster Exclude debug_only Debug/developer option; can produce high-volume internal debug output and distort benchmarks.
debug_logical_replication_streaming — — — enum user Exclude debug_only Debug/developer option; not valid for production workload tuning.
debug_parallel_query — — — enum user Exclude debug_only Debug/developer option; not valid for production workload tuning.
debug_pretty_print — — — bool user Exclude debug_only Debug/developer option; not valid for production workload tuning.
debug_print_parse — — — bool user Exclude debug_only Debug/developer option; not valid for production workload tuning.
debug_print_plan — — — bool user Exclude debug_only Debug/developer option; not valid for production workload tuning.
debug_print_rewritten — — — bool user Exclude debug_only Debug/developer option; not valid for production workload tuning.
default_statistics_target 10 10000 — integer user Include admitted_curated Statistics sample size for ANALYZE. Higher = better plans, slower ANALYZE.
default_table_access_method — — — string user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
default_tablespace — — — string user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
default_text_search_config — — — string user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
default_toast_compression — — — enum user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
default_transaction_deferrable — — — bool user Exclude semantic_behavior Changes SQL behavioral semantics rather than performance characteristics.
default_transaction_isolation — — — enum user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
default_transaction_read_only — — — bool user Exclude semantic_behavior Changes SQL behavioral semantics rather than performance characteristics.
dynamic_library_path — — — string superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
dynamic_shared_memory_type — — — enum postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
effective_cache_size 65536 1048576 8kB integer user Include admitted_curated Planner's OS cache estimate. Doesn't allocate memory, only affects plans.
effective_io_concurrency 0 200 — integer user Include admitted_curated Expected concurrent I/O. SSD: 100-200, HDD: 1-2
enable_async_append — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
enable_bitmapscan — — — bool user Include admitted_curated Enable bitmap scans.
enable_distinct_reordering — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
enable_gathermerge — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
enable_group_by_reordering — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
enable_hashagg — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
enable_hashjoin — — — bool user Include admitted_curated Enable hash joins.
enable_incremental_sort — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
enable_indexonlyscan — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
enable_indexscan — — — bool user Include admitted_curated Enable index scans. Usually leave on.
enable_material — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
enable_memoize — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
enable_mergejoin — — — bool user Include admitted_curated Enable merge joins.
enable_nestloop — — — bool user Include admitted_curated Enable nested loop joins.
enable_parallel_append — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
enable_parallel_hash — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
enable_partition_pruning — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
enable_partitionwise_aggregate — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
enable_partitionwise_join — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
enable_presorted_aggregate — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
enable_self_join_elimination — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
enable_seqscan — — — bool user Include admitted_curated Enable sequential scans. Usually leave on.
enable_sort — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
enable_tidscan — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
escape_string_warning — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
event_source — — — string postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
event_triggers — — — bool superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
exit_on_error — — — bool user Exclude stability Alters error/crash behavior and destabilizes tuning loop execution.
extension_control_path — — — string superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
external_pid_file — — — string postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
extra_float_digits -15.0 3.0 — integer user Exclude semantic_behavior Client display precision; semantic client behavior, not server performance.
file_copy_method — — — enum user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
file_extend_method — — — enum sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
from_collapse_limit 1.0 2147483647.0 — integer user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
fsync — — — bool sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
full_page_writes — — — bool sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
geqo — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
geqo_effort 1 10 — integer user Include admitted_curated GEQO effort level.
geqo_generations 0.0 2147483647.0 — integer user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
geqo_pool_size 0.0 2147483647.0 — integer user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
geqo_seed 0.0 1.0 — real user Include admitted_curated GEQO random seed.
geqo_selection_bias 1.5 2.0 — real user Include admitted_curated GEQO selection bias.
geqo_threshold 2.0 2147483647.0 — integer user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
gin_fuzzy_search_limit 0.0 2147483647.0 — integer user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
gin_pending_list_limit 64.0 2147483647.0 kB integer user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
gss_accept_delegation — — — bool sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
hash_mem_multiplier 1.0 8.0 — real user Include admitted_curated Hash operation memory multiplier; bounded to avoid aggressive memory oversubscription.
hba_file — — — string postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
hot_standby — — — bool postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
hot_standby_feedback — — — bool sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
huge_page_size 0.0 2147483647.0 kB integer postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
huge_pages — — — enum postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
huge_pages_status — — — enum internal Exclude internal_context Internal parameters cannot be modified via PostgreSQL runtime/config interfaces.
icu_validation_level — — — enum user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
ident_file — — — string postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
idle_in_transaction_session_timeout 0.0 2147483647.0 ms integer user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
idle_replication_slot_timeout 0.0 2147483647.0 s integer sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
idle_session_timeout 0.0 2147483647.0 ms integer user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
ignore_checksum_failure — — — bool superuser Exclude data_integrity Dangerous data-integrity bypass option; excluded from autotuning.
ignore_invalid_pages — — — bool postmaster Exclude data_integrity Dangerous data-integrity bypass option; excluded from autotuning.
ignore_system_indexes — — — bool backend Exclude data_integrity Dangerous data-integrity bypass option; excluded from autotuning.
in_hot_standby — — — bool internal Exclude internal_context Internal parameters cannot be modified via PostgreSQL runtime/config interfaces.
integer_datetimes — — — bool internal Exclude internal_context Internal parameters cannot be modified via PostgreSQL runtime/config interfaces.
io_combine_limit 1 128 8kB integer user Include admitted_curated I/O combine limit.
io_max_combine_limit 1 128 8kB integer postmaster Include admitted_curated Max I/O combine limit.
io_max_concurrency -1 256 — integer postmaster Include admitted_curated Max I/O concurrency.
io_method — — — enum postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
io_workers 1 16 — integer sighup Include admitted_curated I/O worker count (PG17+); bounded to practical CPU-core-aligned range.
jit — — — bool user Exclude stability Known instability for benchmark workloads in this environment.
jit_above_cost -1.0 1.79769e+308 — real user Exclude stability Known instability for benchmark workloads in this environment.
jit_debugging_support — — — bool superuser-backend Exclude stability Known instability for benchmark workloads in this environment.
jit_dump_bitcode — — — bool superuser Exclude stability Known instability for benchmark workloads in this environment.
jit_expressions — — — bool user Exclude stability Known instability for benchmark workloads in this environment.
jit_inline_above_cost -1.0 1.79769e+308 — real user Exclude stability Known instability for benchmark workloads in this environment.
jit_optimize_above_cost -1.0 1.79769e+308 — real user Exclude stability Known instability for benchmark workloads in this environment.
jit_profiling_support — — — bool superuser-backend Exclude stability Known instability for benchmark workloads in this environment.
jit_provider — — — string postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
jit_tuple_deforming — — — bool user Exclude stability Known instability for benchmark workloads in this environment.
join_collapse_limit 1.0 2147483647.0 — integer user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
krb_caseins_users — — — bool sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
krb_server_keyfile — — — string sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
lc_messages — — — string superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
lc_monetary — — — string user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
lc_numeric — — — string user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
lc_time — — — string user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
listen_addresses — — — string postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
lo_compat_privileges — — — bool superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
local_preload_libraries — — — string user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
lock_timeout 0.0 2147483647.0 ms integer user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
log_autovacuum_min_duration -1.0 2147483647.0 ms integer sighup Exclude benchmark_validity Autovacuum logging threshold; does not affect actual maintenance pacing.
log_checkpoints — — — bool sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
log_connections — — — string superuser-backend Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
log_destination — — — string sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
log_directory — — — string sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
log_disconnections — — — bool superuser-backend Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
log_duration — — — bool superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
log_error_verbosity — — — enum superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
log_executor_stats — — — bool superuser Exclude mutual_exclusion Mutually exclusive with statement/parser/planner stats and can cause config errors.
log_file_mode 0.0 511.0 — integer sighup Exclude format_readback Octal-mode parameter with unreliable readback/validation in this pipeline.
log_filename — — — string sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
log_hostname — — — bool sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
log_line_prefix — — — string sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
log_lock_failures — — — bool superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
log_lock_waits — — — bool superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
log_min_duration_sample -1.0 2147483647.0 ms integer superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
log_min_duration_statement -1.0 2147483647.0 ms integer superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
log_min_error_statement — — — enum superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
log_min_messages — — — enum superuser Exclude benchmark_validity Low log-level settings (debug*) can flood logs and materially skew benchmark timing.
log_parameter_max_length -1.0 1073741823.0 B integer superuser Exclude benchmark_validity Log truncation limit; does not affect workload performance.
log_parameter_max_length_on_error -1.0 1073741823.0 B integer user Exclude benchmark_validity Error log truncation; does not affect workload performance.
log_parser_stats — — — bool superuser Exclude mutual_exclusion Mutually exclusive with statement/planner/executor stats and can cause config errors.
log_planner_stats — — — bool superuser Exclude mutual_exclusion Mutually exclusive with statement/parser/executor stats and can cause config errors.
log_recovery_conflict_waits — — — bool sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
log_replication_commands — — — bool superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
log_rotation_age 0.0 35791394.0 min integer sighup Exclude benchmark_validity Log file rotation schedule; does not affect workload performance.
log_rotation_size 0.0 2147483647.0 kB integer sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
log_startup_progress_interval 0.0 2147483647.0 ms integer sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
log_statement — — — enum superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
log_statement_sample_rate 0.0 1.0 — real superuser Exclude benchmark_validity Fraction of statements logged; can skew benchmark measurements.
log_statement_stats — — — bool superuser Exclude mutual_exclusion Mutually exclusive with parser/planner/executor stats and can cause config errors.
log_temp_files -1.0 2147483647.0 kB integer superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
log_timezone — — — string sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
log_transaction_sample_rate 0.0 1.0 — real superuser Exclude benchmark_validity Fraction of transactions logged; can skew benchmark measurements.
log_truncate_on_rotation — — — bool sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
logging_collector — — — bool postmaster Exclude logging_pipeline_dependency Redirects logs and interferes with restart/log-driven orchestration behavior.
logical_decoding_work_mem 64.0 2147483647.0 kB integer user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
maintenance_io_concurrency 0 200 — integer user Include admitted_curated Maintenance I/O concurrency for VACUUM/CREATE INDEX, similar semantics to effective_io_concurrency.
maintenance_work_mem 65536 262144 kB integer user Include admitted_curated For VACUUM, CREATE INDEX. Can be larger than work_mem.
max_active_replication_origins 0.0 262143.0 — integer postmaster Exclude benchmark_validity Replication origin slots; not relevant as benchmarks don't use replication fanout.
max_connections 50 200 — integer postmaster Include admitted_curated Max concurrent connections. Requires restart. High values increase memory.
max_files_per_process 64.0 2147483647.0 — integer postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
max_function_args 100.0 100.0 — integer internal Exclude internal_context Internal parameters cannot be modified via PostgreSQL runtime/config interfaces.
max_identifier_length 63.0 63.0 — integer internal Exclude internal_context Internal parameters cannot be modified via PostgreSQL runtime/config interfaces.
max_index_keys 32.0 32.0 — integer internal Exclude internal_context Internal parameters cannot be modified via PostgreSQL runtime/config interfaces.
max_locks_per_transaction 10.0 2147483647.0 — integer postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
max_logical_replication_workers 0 10 — integer postmaster Include admitted_curated Logical replication worker cap; bounded for stability in non-replication-centric tuning runs.
max_notify_queue_pages 64.0 2147483647.0 — integer postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
max_parallel_apply_workers_per_subscription 0 8 — integer sighup Include admitted_curated Logical replication apply parallelism; low-impact for non-replication benchmarks but safely tunable.
max_parallel_maintenance_workers 0 4 — integer user Include admitted_curated Max parallel workers for maintenance (CREATE INDEX, VACUUM).
max_parallel_workers 0 16 — integer user Include admitted_curated Max parallel workers system-wide. Must be <= max_worker_processes.
max_parallel_workers_per_gather 0 4 — integer user Include admitted_curated Parallelism for analytical queries. Limited by CPU cores.
max_pred_locks_per_page 0.0 2147483647.0 — integer sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
max_pred_locks_per_relation -2147483648.0 2147483647.0 — integer sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
max_pred_locks_per_transaction 10.0 2147483647.0 — integer postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
max_prepared_transactions 0.0 262143.0 — integer postmaster Exclude benchmark_validity 2PC transaction slots; not used by standard OLTP/OLAP benchmarks.
max_replication_slots 0.0 262143.0 — integer postmaster Exclude benchmark_validity Replication slot cap; not relevant as benchmarks don't use replication fanout.
max_slot_wal_keep_size -1.0 2147483647.0 MB integer sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
max_stack_depth 100.0 2147483647.0 kB integer superuser Exclude os_alignment Depends on OS stack limits and can crash backend when misaligned.
max_standby_archive_delay -1.0 2147483647.0 ms integer sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
max_standby_streaming_delay -1.0 2147483647.0 ms integer sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
max_sync_workers_per_subscription 0.0 262143.0 — integer sighup Exclude benchmark_validity Sync parallelism for replication; not relevant for standalone benchmarks.
max_wal_senders 0 10 — integer postmaster Include admitted_curated WAL sender process cap; safely bounded for environments without heavy replication fanout.
max_wal_size 80 10240 MB integer sighup Include admitted_curated Max WAL size before forced checkpoint.
max_worker_processes 4 16 — integer postmaster Include admitted_curated Max background workers. Requires restart. Must be >= max_parallel_workers.
md5_password_warnings — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
min_dynamic_shared_memory 0.0 2147483647.0 MB integer postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
min_parallel_index_scan_size 0 16384 8kB integer user Include admitted_curated pages required to trigger parallel index scan.
min_parallel_table_scan_size 0 65536 8kB integer user Include admitted_curated pages required to trigger parallel table scan.
min_wal_size 80 2048 MB integer sighup Include admitted_curated Minimum WAL size to keep.
multixact_member_buffers 4 64 8kB integer postmaster Include admitted_curated MultiXact member SLRU buffers (pages); bounded for stable memory usage.
multixact_offset_buffers 4 64 8kB integer postmaster Include admitted_curated MultiXact offset SLRU buffers (pages); bounded for stable memory usage.
notify_buffers 4 64 8kB integer postmaster Include admitted_curated LISTEN/NOTIFY buffers (pages); bounded for safe memory footprint.
num_os_semaphores 0.0 2147483647.0 — integer internal Exclude internal_context Internal parameters cannot be modified via PostgreSQL runtime/config interfaces.
oauth_validator_libraries — — — string sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
parallel_leader_participation — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
parallel_setup_cost 1.0 10000.0 — real user Include admitted_curated Cost of starting parallel workers.
parallel_tuple_cost 0.0001 10.0 — real user Include admitted_curated Cost of transferring tuples between workers.
password_encryption — — — enum user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
plan_cache_mode — — — enum user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
port 1.0 65535.0 — integer postmaster Exclude network_binding Instance network binding parameter; not workload performance tuning.
post_auth_delay 0.0 2147.0 s integer backend Exclude benchmark_validity Artificially delays post-auth processing and distorts benchmark latency.
pre_auth_delay 0.0 60.0 s integer sighup Exclude benchmark_validity Artificially delays connection auth and distorts benchmark latency.
primary_conninfo — — — string sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
primary_slot_name — — — string sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
quote_all_identifiers — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
random_page_cost 0.1 4.0 — real user Include admitted_curated Critical for index vs seqscan decisions. SSD: 1.0-1.5, HDD: 3.0-4.0
recovery_end_command — — — string sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
recovery_init_sync_method — — — enum sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
recovery_min_apply_delay 0.0 2147483647.0 ms integer sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
recovery_prefetch — — — enum sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
recovery_target — — — string postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
recovery_target_action — — — enum postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
recovery_target_inclusive — — — bool postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
recovery_target_lsn — — — string postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
recovery_target_name — — — string postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
recovery_target_time — — — string postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
recovery_target_timeline — — — string postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
recovery_target_xid — — — string postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
recursive_worktable_factor 0.1 100.0 — real user Include admitted_curated planner multiplier for recursive queries.
remove_temp_files_after_crash — — — bool sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
reserved_connections 0 5 — integer postmaster Include admitted_curated Reserved connection slots; conservative bounds preserve user connection capacity.
restart_after_crash — — — bool sighup Exclude stability Alters crash recovery behavior and destabilizes tuning loop execution.
restore_command — — — string sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
restrict_nonsystem_relation_kind — — — string user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
row_security — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
scram_iterations 1.0 2147483647.0 — integer user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
search_path — — — string user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
segment_size 131072.0 131072.0 8kB integer internal Exclude internal_context Internal parameters cannot be modified via PostgreSQL runtime/config interfaces.
send_abort_for_crash — — — bool sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
send_abort_for_kill — — — bool sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
seq_page_cost 0.1 2.0 — real user Include admitted_curated Cost of sequential page fetch. Usually kept at 1.0 as baseline.
serializable_buffers 16 1024 8kB integer postmaster Include admitted_curated SLRU buffers for serializable transactions (must be multiple of 16).
server_encoding — — — string internal Exclude internal_context Internal parameters cannot be modified via PostgreSQL runtime/config interfaces.
server_version — — — string internal Exclude internal_context Internal parameters cannot be modified via PostgreSQL runtime/config interfaces.
server_version_num 180003.0 180003.0 — integer internal Exclude internal_context Internal parameters cannot be modified via PostgreSQL runtime/config interfaces.
session_preload_libraries — — — string superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
session_replication_role — — — enum superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
shared_buffers 16384 131072 8kB integer postmaster Include admitted_curated Most impactful knob. Log scale because doubling matters more than addition.
shared_memory_size 0.0 2147483647.0 MB integer internal Exclude internal_context Internal parameters cannot be modified via PostgreSQL runtime/config interfaces.
shared_memory_size_in_huge_pages -1.0 2147483647.0 — integer internal Exclude internal_context Internal parameters cannot be modified via PostgreSQL runtime/config interfaces.
shared_memory_type — — — enum postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
shared_preload_libraries — — — string postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
ssl — — — bool sighup Exclude security_transport Security transport policy parameter, excluded from autotuning scope.
ssl_ca_file — — — string sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
ssl_cert_file — — — string sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
ssl_ciphers — — — string sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
ssl_crl_dir — — — string sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
ssl_crl_file — — — string sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
ssl_dh_params_file — — — string sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
ssl_groups — — — string sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
ssl_key_file — — — string sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
ssl_library — — — string internal Exclude internal_context Internal parameters cannot be modified via PostgreSQL runtime/config interfaces.
ssl_max_protocol_version — — — enum sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
ssl_min_protocol_version — — — enum sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
ssl_passphrase_command — — — string sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
ssl_passphrase_command_supports_reload — — — bool sighup Exclude security_transport Security transport policy parameter, excluded from autotuning scope.
ssl_prefer_server_ciphers — — — bool sighup Exclude security_transport Security transport policy parameter, excluded from autotuning scope.
ssl_tls13_ciphers — — — string sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
standard_conforming_strings — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
statement_timeout 0.0 2147483647.0 ms integer user Exclude benchmark_validity Can cancel post-workload maintenance and produce false failure signals.
stats_fetch_consistency — — — enum user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
subtransaction_buffers 0 1024 8kB integer postmaster Include admitted_curated SLRU buffers for subtransactions (must be multiple of 16).
summarize_wal — — — bool sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
superuser_reserved_connections 0 5 — integer postmaster Include admitted_curated Reserved connection slots for superusers; tuned conservatively to prevent starvation.
sync_replication_slots — — — bool sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
synchronize_seqscans — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
synchronized_standby_slots — — — string sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
synchronous_commit — — — enum user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
synchronous_standby_names — — — string sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
syslog_facility — — — enum sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
syslog_ident — — — string sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
syslog_sequence_numbers — — — bool sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
syslog_split_messages — — — bool sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
tcp_keepalives_count 0.0 2147483647.0 — integer user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
tcp_keepalives_idle 0.0 2147483647.0 s integer user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
tcp_keepalives_interval 0.0 2147483647.0 s integer user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
tcp_user_timeout 0.0 2147483647.0 ms integer user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
temp_buffers 1024 4096 8kB integer user Include admitted_curated Temp buffer size per session.
temp_file_limit -1.0 2147483647.0 kB integer superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
temp_tablespaces — — — string user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
timezone_abbreviations — — — string user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
trace_connection_negotiation — — — bool postmaster Exclude debug_only Debug/developer trace option; can generate noisy logs and perturb timing.
trace_notify — — — bool user Exclude debug_only Debug/developer trace option; can generate noisy logs and perturb timing.
trace_sort — — — bool user Exclude debug_only Debug/developer trace option; can generate noisy logs and perturb timing.
track_activities — — — bool superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
track_activity_query_size 100.0 1048576.0 B integer postmaster Exclude benchmark_validity pg_stat_activity query truncation; memory overhead is trivial and unmeasured.
track_commit_timestamp — — — bool postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
track_cost_delay_timing — — — bool superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
track_counts — — — bool superuser Exclude debug_only Disabling stats collection causes errors and prevents collection of important metrics
track_functions — — — enum superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
track_io_timing — — — bool superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
track_wal_io_timing — — — bool superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
transaction_buffers 0 1024 8kB integer postmaster Include admitted_curated SLRU buffers for transactions (must be multiple of 16).
transaction_deferrable — — — bool user Exclude session_semantics Transaction/session semantic toggle, not a stable global performance knob.
transaction_isolation — — — enum user Exclude session_semantics Transaction/session semantic toggle, not a stable global performance knob.
transaction_read_only — — — bool user Exclude session_semantics Transaction/session semantic toggle, not a stable global performance knob.
transaction_timeout 0.0 2147483647.0 ms integer user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
transform_null_equals — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
unix_socket_directories — — — string postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
unix_socket_group — — — string postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
unix_socket_permissions 0.0 511.0 — integer postmaster Exclude format_readback Octal-mode parameter with unreliable readback/validation in this pipeline.
update_process_title — — — bool superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
vacuum_buffer_usage_limit 128 2048 kB integer user Include admitted_curated buffer usage limit for vacuum (pages).
vacuum_cost_delay 0.0 100.0 ms real user Exclude maintenance_only Manual VACUUM cost delay affects only post-workload unmeasured maintenance.
vacuum_cost_limit 1 2000 — integer user Include admitted_curated aggregate cost cap for vacuum.
vacuum_cost_page_dirty 0 1000 — integer user Include admitted_curated cost of dirtying a page.
vacuum_cost_page_hit 0 100 — integer user Include admitted_curated cost of vacuuming a buffer-hit page.
vacuum_cost_page_miss 0 1000 — integer user Include admitted_curated cost of vacuuming a disk-read page.
vacuum_failsafe_age 0.0 2100000000.0 — integer user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
vacuum_freeze_min_age 0 100000000 — integer user Include admitted_curated minimum age before freezing tuples.
vacuum_freeze_table_age 0.0 2000000000.0 — integer user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
vacuum_max_eager_freeze_failure_rate 0.0 1.0 — real user Include admitted_native_bounded Safe bounded native PostgreSQL domain (real). Included as an extensive-tier candidate.
vacuum_multixact_failsafe_age 0.0 2100000000.0 — integer user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
vacuum_multixact_freeze_min_age 0 100000000 — integer user Include admitted_curated minimum age before freezing multixacts.
vacuum_multixact_freeze_table_age 0.0 2000000000.0 — integer user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
vacuum_truncate — — — bool user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
wal_block_size 8192.0 8192.0 — integer internal Exclude internal_context Internal parameters cannot be modified via PostgreSQL runtime/config interfaces.
wal_buffers 64 2048 8kB integer postmaster Include admitted_curated WAL buffer size. Default -1 means auto (1/32 of shared_buffers).
wal_compression — — — enum superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
wal_consistency_checking — — — string superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
wal_decode_buffer_size 65536.0 1073741823.0 B integer postmaster Exclude benchmark_validity Recovery decode buffer; benchmarks measure normal execution, not crash recovery.
wal_init_zero — — — bool superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
wal_keep_size 0.0 2147483647.0 MB integer sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
wal_level — — — enum postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
wal_log_hints — — — bool postmaster Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
wal_receiver_create_temp_slot — — — bool sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
wal_receiver_status_interval 0.0 2147483.0 s integer sighup Exclude benchmark_validity Replication heartbeat interval; not relevant for standalone benchmarks.
wal_receiver_timeout 0.0 2147483647.0 ms integer sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
wal_recycle — — — bool superuser Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
wal_retrieve_retry_interval 1.0 2147483647.0 ms integer sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
wal_segment_size 1048576.0 1073741824.0 B integer internal Exclude internal_context Internal parameters cannot be modified via PostgreSQL runtime/config interfaces.
wal_sender_timeout 0.0 2147483647.0 ms integer user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
wal_skip_threshold 0.0 2147483647.0 kB integer user Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
wal_summary_keep_time 0.0 35791394.0 min integer sighup Exclude benchmark_validity WAL summary retention; does not affect workload performance.
wal_sync_method — — — enum sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
wal_writer_delay 1 5000 ms integer sighup Include admitted_curated ms between WAL flushes.
wal_writer_flush_after 0.0 2147483647.0 8kB integer sighup Exclude uncurated_intmax_sentinel Native max value is INT_MAX-sentinel/unbounded; requires curated practical bounds before safe autotuning admission.
work_mem 4096 65536 kB integer user Include admitted_curated Per-operation memory. Total can be work_mem _ connections _ operations_per_query
xmlbinary — — — enum user Exclude semantic_behavior XML encoding toggle; semantic client behavior, not server performance.
xmloption — — — enum user Exclude semantic_behavior XML default handling; semantic client behavior, not server performance.
zero_damaged_pages — — — bool superuser Exclude data_integrity Dangerous data-integrity bypass option; excluded from autotuning.