Flags & Environment Variables

ReferenceConfigurationOperations

Stable On by default · production-ready · inventory taken from the daemon source; defaults are the shipped daemon's, not the library's

This page lists every control surface the daemon exposes. The shorter Configuration & Availability page is the curated view that feature pages link to; this one is the exhaustive inventory for operators who need to know exactly what a knob does before touching it.

Feature flags versus settings

Every switch on this page is one of two kinds. Keep the distinction in mind; it decides where to look and what a change means.

Kind	What it changes	Examples	Granularity
Feature flag	Whether the database has a capability. Turning one on adds a subsystem, a listener, a tier or a language surface. Turning it off removes it.	HTAP, cluster mode, multi-tenancy, Flight SQL, streaming connectors, RLS	Coarse: a few dozen. These are the units the product is described in.
Setting	How an enabled capability behaves. Sizes, budgets, ports, timers, thresholds, and the kill switches that pick one execution route over another. Results never change; cost and placement do.	memory budget, spill dir, join partitions, watchdog budget, AETHERIUS_INLJ=0	Fine: about a hundred and fifty. Tuned per host and per workload.

Feature flags are documented once, in the Feature flags table. Settings are grouped by subsystem under Settings.

The license can override a feature flag. A grant in license.key wins over the command line and the environment in both directions. HTAP, cluster mode, multi-tenancy and high availability are premium features: they are off unless the key grants them, and their flags below are inert on a daemon that has evaluated a license. To license them, contact the AetheriusDB team at aetheriusdb.com or aetheriuslabs.com. See Licensing → Premium features.

The control surfaces

Surface	How many	Where it is read	Takes effect
Command-line flags on aetheriusd	65 on the main command, 7 on subcommands	at process start	next restart
AETHERIUS_* environment variables	about 120	at process start (a few are read on first use)	next restart
SQL SET variables	3 with behaviour	per session, at statement time	immediately, that session only
RuntimeConfig fields (library)	96	when the runtime is constructed	embedders only; the daemon exposes 33 of them

Precedence

Where a switch exists on more than one surface the daemon resolves it as

command-line flag  >  environment variable  >  built-in default

A flag always wins over the variable. For switches that are on by default, the env var is a kill switch (=0 turns it off); for switches that are off by default, the env var is an opt-in (=1 turns it on).

Value formats

Kind	Accepted values
Opt-in toggle (AETHERIUS_ENABLE_*, AETHERIUS_DISABLE_*, AETHERIUS_CLUSTER_MODE, …)	1 or true (case-insensitive). Anything else, or unset, is off.
Kill switch on a default-on path (AETHERIUS_INLJ, AETHERIUS_COPY_APPEND, …)	0 or false turns it off. Any other value, or unset, leaves it on. A few also accept off.
Numeric knob	A plain integer (bytes, rows, milliseconds). Unparsable or out-of-range values fall back to the default rather than disabling the feature. 0 usually means “no limit” or “disabled”; the tables say which.
Path / string	Used as-is.

How to set them

Shell, for a foreground run

AETHERIUS_ENABLE_HTAP=1 AETHERIUS_MEM_BUDGET_FRACTION=0.6 \
  aetheriusd --data-dir /var/lib/aetherius --enable-parallel --enable-query-watchdog

systemd (Linux installs) — never edit the shipped unit; add a drop-in:

sudo systemctl edit aetheriusd

[Service]
Environment=AETHERIUS_ENABLE_HTAP=1
Environment=AETHERIUS_MEM_BUDGET_FRACTION=0.6
# To add flags, override ExecStart (the empty line first is required):
ExecStart=
ExecStart=/usr/local/bin/aetheriusd --data-dir /var/lib/aetherius --enable-parallel --enable-query-watchdog

sudo systemctl daemon-reload && sudo systemctl restart aetheriusd

launchd (macOS installs) — edit the plist under /Library/LaunchDaemons/dev.aetherius.aetheriusd.plist: flags go in ProgramArguments, variables in an EnvironmentVariables dictionary. Then:

sudo launchctl kickstart -k system/dev.aetherius.aetheriusd

Docker / compose — -e AETHERIUS_ENABLE_HTAP=1 and append flags to the container command.

Per session — SET name = value; over any wire protocol; see SQL SET variables.

Confirm what took effect from the boot banner:

sudo journalctl -u aetheriusd -n 80 --no-pager    # Linux

The banner prints the security posture, WASM-aggregate mode, deployment mode, license state and watchdog state. There is no SQL view that reports the active flag set.

Feature flags

One row per capability. Turn on / off names the switch on each surface; where a flag and a variable both exist, the flag wins. The Default column is what a plain aetheriusd does with no switches.

Storage and transactions

Feature	Default	Turn on / off	What it adds
ACube columnar storage	on	--enable-acube-storage (kept for back-compat; leave on)	The 64 MiB slab engine everything else sits on.
HTAP	off · Premium	--enable-htap · AETHERIUS_ENABLE_HTAP=1 (inert once a license is evaluated; the key’s htap grant decides)	A mutable Delta tier over the sealed slabs per table: snapshot isolation, write-write conflict detection (SQLSTATE 40001), PK point-lookup dispatch, background Loom promotion to sealed slabs.
Persistent Tree Index (PTI)	off	--enable-pti	Secondary tree indexes with header-resident PK structures.
Chrono-Stripe persistence	off	--enable-chrono-stripe	Parallel striped persistence.
UDRF tiered residency	off	--enable-udrf	Hot / warm / cold data tiers with a horizon daemon.
SAL ingest	off	--enable-sal-ingest	Lock-free producer queue plus drain thread; producers are acked after the commit bit flips.
Write-Loom	off	--enable-loom	Schema-evolution transforms at write time.

Query engine

Feature	Default	Turn on / off	What it adds
Query optimizer	off on the daemon	--enable-optimizer	Rule-based plan rewriting. The library default is on; the daemon only enables it with the flag.
Morsel-parallel execution	off	--enable-parallel	Multi-core scans, joins, aggregates and window functions. Without it every query runs on one core. Refined by the AETHERIUS_PARALLEL_* settings.
JIT compilation	off	--enable-jit · AETHERIUS_ENABLE_JIT=1	Cranelift compilation of Sort / Agg / Join plans.
Adaptive query execution	off	--enable-aqe	Re-plans mid-flight from observed cardinalities.
Join-Graph auto-index	on	--disable-join-graph · AETHERIUS_DISABLE_JOIN_GRAPH=1	Eligible inner equi-joins capture a positional edge on first run and are served as address walks afterwards.
Cognitive Schema nervous system	on	--disable-nervous-system · AETHERIUS_DISABLE_NERVOUS_SYSTEM=1	Acts on declared cognitive properties at query time: Nervous-Path routing, Projection-Cube bypass, Pre-Cook serving, system.* cognitive views. Declarations stay stored when off.
WASM-cell aggregates	on	--disable-cell-wasm-aggregates · AETHERIUS_CELL_WASM_AGGREGATES=0	Narrow aggregates run inside the WASM sandbox instead of the host kernel. Byte-identical results.
Index advisor	off	--enable-index-advisor · AETHERIUS_ENABLE_INDEX_ADVISOR=1	Observes predicate columns and accumulates index recommendations. Recommend only.
Autonomous indexing	off	--enable-autonomous-indexing · AETHERIUS_ENABLE_AUTONOMOUS_INDEXING=1	The advisor creates real tree indexes itself (throttled, never UNIQUE). Needs the advisor on.
Auto materialized views (AVMM)	off	--enable-avmm	Autonomous view and materialization manager.
Anomaly detection	off	--enable-anomaly	Anomaly-detection engine.
Temporal pattern matching	off	--enable-temporal-nfa	NFA-based temporal event patterns.

Security and access

Feature	Default	Turn on / off	What it adds
RBAC authentication	on	--disable-security turns it off	Loopback peers are trusted as superuser; remote peers must match an RBAC user (seed one with aetheriusd bootstrap). Off restores trust-everyone mode.
Row-level security	off	--enable-rls	Policy enforcement per row.
Native protocol auth	off	--native-auth-token TOK · AETHERIUS_NATIVE_AUTH_TOKEN	Bearer token required on the native listener.
Flight SQL auth	off	--flight-auth-token TOK · AETHERIUS_FLIGHT_AUTH_TOKEN	Bearer token required on Flight SQL.
Signed cell artifacts	off	--cell-signer-key HEX64 (repeatable) · AETHERIUS_CELL_SIGNER_KEYS	Supplying any key turns signature enforcement on for DEPLOY CELLS. A trust root, deliberately not SQL-manageable. A malformed key aborts startup.
Non-loopback bind without auth	refused	--insecure-no-auth	Acknowledge exposing an unauthenticated pgwire port. Strongly discouraged.

Wire protocols

Feature	Default	Turn on / off	What it adds
PostgreSQL wire protocol	on	always on; port via --port	psycopg, asyncpg, JDBC, SQLAlchemy.
Native Aether-Sync protocol	on	--disable-native	The zero-copy binary protocol.
Arrow Flight SQL	on	--disable-flight (--enable-flight is a hidden no-op); a flight=off license grant also disables it	Columnar egress for ADBC and Arrow clients.
ANBF bulk-ingest listener	off	--ingest-port N (0 = off)	Dedicated bulk-ingest socket.
Async pgwire ring	off	--async-ring	Cooperative-multiplexing listener. Needs the async-ring build feature; no SCRAM on this path.

Compute cells and deployment topology

Feature	Default	Turn on / off	What it adds
External cell fleet	off	--enable-external-cells · AETHERIUS_ENABLE_EXTERNAL_CELLS=1	Route compute cells to an external worker fleet through the hybrid dispatcher. Falls back in-process unless strict mode is set.
Multi-process deployment	single	--deployment-mode multi (needs --cell-binary and --socket-dir)	A hypervisor with one aether-cell child process per database.
Compute push	off	--enable-compute-push	Compute-push offload.
Logic-Loom orchestration	off	--enable-logic-loom	Logic-Loom orchestration.
WASM edge compute	off	--enable-wasm-edge	WASM edge execution.

Distributed

Feature	Default	Turn on / off	What it adds
Cluster orchestrator	off · Premium	AETHERIUS_CLUSTER_MODE=1 (needs the key’s cluster grant)	This process routes statements to the workers named in the topology; single-table selects, aggregates, GROUP BY and two-table joins compile to bytecode and run remotely. Decided once at boot.
Cluster worker	off · Premium	AETHERIUS_WORKER_MODE=<cluster> (exits without the key’s cluster grant)	This process serves one cluster’s containers. No SQL surface.
Multi-tenancy	off · Premium	AETHERIUS_ENABLE_MULTI_TENANCY=1 (inert without the key’s multi_tenancy grant)	Accept tenants other than tenant 0. Off: any other tenant is refused before routing.
Raft metadata cluster	off	--cluster-mode with --node-id and --raft-peers	Raft-replicated metadata node. Distinct from the query-routing orchestrator above.
Aether-Sync replication / HA	off · Premium	--enable-sync; the key’s replication grant (enforcement pending)	Replication over the native protocol; standby VMs via the Shadow HA stream.
CDC bridge connectors	off	--enable-bridge	External change-data-capture bridges.

Operations

Feature	Default	Turn on / off	What it adds
Query watchdog	off	--enable-query-watchdog · AETHERIUS_ENABLE_QUERY_WATCHDOG=1	Abort statements past their budget (SQLSTATE 57014) and cancel statements whose client disconnected. Without it a disconnected client’s query runs until restart. Budgets are settings below.
License enforcement	on when a key is found	--license-file PATH · AETHERIUS_LICENSE_FILE · /etc/aetherius/license.key	Signed size / expiry / upgrade-window limits, feature grants and machine binding. Without a valid key the daemon boots read-only. See Licensing.

Modes and subcommands

Invocation	What it does
aetheriusd --repl or aetheriusd repl	Interactive SQL REPL instead of the server.
aetheriusd backup --to PATH	Write a phantom-backup ChronoAnchor.
aetheriusd restore --from PATH	Restore from a ChronoAnchor.
aetheriusd migrate	Offline, read-only: report the on-disk container format and whether this build can read it. Run before upgrading.
aetheriusd repair [--apply] [--purge-schema S]	Offline fsck. Dry-run unless --apply. Daemon must be stopped.
aetheriusd bootstrap --superuser NAME [--password PW]	Seed a superuser into the RBAC snapshot. Daemon must be stopped.
aetheriusd verify-license --file PATH	Verify a license against this binary’s embedded key; print limits, feature grants and binding. Exit 0 valid, 1 invalid, 2 unreadable.
aetheriusd fingerprint	Print this machine’s 64-hex license fingerprint for a machine-bound key.

Settings

Settings tune a feature that is already on. Changing one never changes a query’s result, only its cost or placement. Kill switches (=0) exist so support can isolate a suspect execution route on a live system; they are not product options.

Network

Setting	Default	What it does
--host ADDR	127.0.0.1	Bind address for every listener. A non-loopback address is refused unless auth is configured or --insecure-no-auth is passed.
--port N / -p N	5678	pgwire port.
--native-port N	5679	Native protocol port.
--flight-port N	8815	Flight SQL port.
--max-connections N	100	Concurrent connection ceiling.

Data directory and storage

Setting	Default	What it does
--data-dir PATH	aetherius_data (relative to the working directory)	Root of all durable state. Global, so it may follow a subcommand.
--compaction-threshold F	0.30	Fragmentation ratio (0.0–1.0) above which a segment is eligible for compaction.
AETHERIUS_CUBE_TARGET_BYTES	67108864 (64 MiB)	Target sealed-cube payload size; both bulk paths seal at this. Floored at 1 MiB.
AETHERIUS_TOPO_MAX_ROWS_PER_BLOCK	2000000	Row ceiling per physical block.
AETHERIUS_GROUP_COMMIT_MS	2000	Time bound on the append writer’s group commit. 0 restores pure batch-count commit.
AETHERIUS_COMPRESS_RESIDENT	off	=1 keeps sealed cubes LZ4-compressed in RAM, decompressing on scan.
AETHERIUS_COMPRESS_DISK	off	=1 lets the re-encode policy LZ4-compress cold columns on disk. Reads decode either way.
AETHERIUS_DICT_ENCODE	off	=1 dictionary-encodes eligible columns when writing. Reads decode either way.
AETHERIUS_VACUUM_DEAD_RATIO	0.30	Dead-byte ratio above which a container is rewritten.
AETHERIUS_VACUUM_AGE_OUT	off	=1 retires wholly superseded write-domain containers by age.
AETHERIUS_INDEX_REBUILD_THREADS	2	Concurrent index rebuilds at boot (1–64). 1 trades wall time for memory headroom.

Memory and spill

Setting	Default	What it does
AETHERIUS_MEM_BUDGET_BYTES	unset	Absolute resident-memory budget for the storage tier. Overrides the fraction.
AETHERIUS_MEM_BUDGET_FRACTION	0.75	Fraction of physical RAM the resident tier may use (0 < f ≤ 1).
AETHERIUS_MEM_BUDGET_FLOOR_MB	512	Floor for the budget on small hosts.
AETHERIUS_MAX_MEMORY_BYTES	66 % of RAM	Process-wide allocation ceiling enforced by the memory guard. 0 opts out.
AETHERIUS_JOIN_BUDGET_BYTES	268435456 (256 MiB)	In-RAM build-side cap for hash joins before they partition to disk.
AETHERIUS_SORT_BUDGET_BYTES	same as join	In-RAM cap for sorts before they spill.
AETHERIUS_SPILL_DIR	data dir	Where grace joins and external sorts spill. Keep it off the data volume on tight hosts.
AETHERIUS_SPILL_LIMIT_BYTES	34359738368 (32 GiB)	Total spill the process may hold. 0 = unlimited.
AETHERIUS_SPILL_FILE_LIMIT_BYTES	8589934592 (8 GiB)	Per-file spill cap. 0 = unlimited.
AETHERIUS_MAX_ROWS_IN_MEMORY	1000000	Rows a single query may buffer. Raise for large INSERT … SELECT migration chunks.
AETHERIUS_PK_DIRECTORY_BYTES	268435456 (256 MiB)	Heap ceiling for cached PK directories (12 bytes/row). 0 never builds or caches.
AETHERIUS_VAR_VIEW_CACHE_BYTES	536870912 (512 MiB)	Cap for the variable-width column view cache. 0 = unlimited.
--micro-slab-pool-mib N · AETHERIUS_MICRO_SLAB_POOL_MIB	4096	Ceiling for the HyperReduced micro-slab pool. Allocated on demand.

Ingest

Setting	Default	What it does
AETHERIUS_INSERT_COLUMNAR	on	=0 disables the columnar fast path for large INSERT … VALUES.
AETHERIUS_INSERT_COLUMNAR_MIN_ROWS	1024	Row count below which an INSERT is OLTP-shaped and stays on the row path.
AETHERIUS_COPY_COLUMNAR	on	=0 disables the columnar COPY path.
AETHERIUS_COPY_APPEND	on	=0 restores the legacy full-base flush after COPY.
AETHERIUS_COPY_ENFORCE_CONSTRAINTS	on	=0 skips the PK/UNIQUE/FK scan during bulk COPY into a constrained table. Unconstrained tables never pay it.
AETHERIUS_INGEST_SPILL	on	Evict each cube’s columns from RAM as soon as it is durably flushed; reload on scan. =0 keeps fresh cubes resident.
BULK_PULSE_V2 / BULK_PULSE_V2_CHUNKS	off / cores	Route source-table CSV ingest through the high-throughput pulse path; chunk count override. No-op on non-ACube backends.

Parallelism

All AETHERIUS_PARALLEL_* switches sit under the --enable-parallel feature: unset they follow it, =0 kills one path independently, any other value forces it on.

Setting	Default	What it does
AETHERIUS_QUERY_WORKERS	performance cores	Worker count for the shared query pool.
AETHERIUS_PARALLEL_SCAN	follows gate	Parallel sealed-cube scan.
AETHERIUS_PARALLEL_SCAN_MIN_ROWS	65536	Below this the scan decodes serially.
AETHERIUS_PARALLEL_JOIN	follows gate	Parallel hash-join probe.
AETHERIUS_PARALLEL_GATHER	on under gate	Parallel gather stage of the join. =0 isolates it.
AETHERIUS_PROBE_COALESCE_ROWS	262144	Rows per coalesced probe block (minimum 4096).
AETHERIUS_PARALLEL_AGG	follows gate	Parallel aggregation fold.
AETHERIUS_PARALLEL_AGG_MIN_ROWS	65536	Below this the fold is serial.
AETHERIUS_PARALLEL_WINDOW	follows gate	Parallel window-function partitions.
AETHERIUS_PIPELINED_AGG	on	=0 forces the serial batch drain before aggregation.

Scan routes (kill switches)

Setting	Default	What it does
AETHERIUS_PHYSICAL_CHUNKS	on	=0 disables physical-chunk scanning.
AETHERIUS_SCAN_PROJECTION_SINGLE	on	=0 restores projection pruning for multi-relation plans only.
AETHERIUS_PAIR_SCAN	on	=0 disables the fused two-table pair scan.
AETHERIUS_REVERSE_SEEK	on	=0 disables the reverse zonemap seek for ORDER BY … DESC LIMIT.
AETHERIUS_SW_PREFETCH	off	=1 enables software prefetch in the aggregate scatter. Measured neutral-to-negative on Apple silicon.

Join routes

Setting	Default	What it does
AETHERIUS_INLJ	on	=0 disables the index-nested-loop probe route at plan time. EXPLAIN reflects it.
AETHERIUS_INLJ_MAX_DRIVE	16384	Driving-side row cap for an unfiltered probe join.
AETHERIUS_INLJ_MAX_DRIVE_FILTERED	100000	Driving-side row cap when the driver is filtered.
AETHERIUS_INLJ_STRICT	off	=1 turns a probe fallback into an error instead of a silent hash join.
AETHERIUS_INLJ_ALLOW_FALLBACK	off	Test lever: suppress the debug assertion on facade-class probe declines.
AETHERIUS_COLUMNAR_JOIN	on	=0 forces the boxed key-table fallback.
AETHERIUS_DENSE_JOIN	on	=0 forces the hash lane instead of the dense key table.
AETHERIUS_GRACE_JOIN	on	=0 disables partitioned (grace) hash joins; large builds then fail on the memory guard instead of spilling.
AETHERIUS_JOIN_PARTITIONS	64	Partition count for grace joins.
AETHERIUS_JOIN_PREFETCH	on	=0 disables prefetch in the join key table.
AETHERIUS_RUNTIME_JOIN_FILTER	on	=0 or off disables build-side runtime filters pushed to the probe scan.
AETHERIUS_JOINGRAPH_BULK_ROWS	200000	Row cap above which a join side is “bulk” for the Join-Graph routing gate.
AETHERIUS_ROW_JOIN_BULK_GATE	on	=0 disables the bulk gate on the row-join path.
AETHERIUS_NAV_CHAIN_COST_GATE	on	=0 disables the cost gate that declines chain-nav joins over large tables.
AETHERIUS_NAV_CHAIN_ROWS	200000	Spine-table row cap for the chain-nav route (falls back to AETHERIUS_JOINGRAPH_BULK_ROWS).
AETHERIUS_GRAPH_INDEX_ACCEL_ROWS	2000000	Row cap above which CREATE GRAPH INDEX skips the acceleration structures. 0 disables them.
AETHERIUS_FK_TOPK_PUSHDOWN	on	=0 disables FK bound-seeding for Top-K joins.
AETHERIUS_CONSTRAINT_PROBE	on	=0 restores scan-based constraint checks on DML.

Aggregation, sort and Top-N routes

Setting	Default	What it does
AETHERIUS_DIRECT_AGG	on	=0 disables the direct array aggregate (COUNT/SUM/MIN/MAX/AVG over numeric columns).
AETHERIUS_DIRECT_AGG_PREFETCH	0	Prefetch lookahead rows for the direct aggregate. Off; re-sweep on x86 before trusting the arm64 result.
AETHERIUS_PRIM_AGG	on	=0 forces the legacy accumulator fold.
AETHERIUS_AGG_PUSHDOWN	off	Optimizer aggregate-pushdown rule. Disabled after it broke one benchmark query with no measured gain.
AETHERIUS_INDEX_ONLY_COUNT	on	=0 answers COUNT(*) from the ordinary aggregate path instead of the index.
AETHERIUS_SORT_DISTINCT	on	=0 disables the sort-based DISTINCT aggregate.
AETHERIUS_EXTERNAL_SORT	on	=0 disables spilling sorts; oversize sorts then fail on the memory guard.
AETHERIUS_SORT_MAX_CHUNK_ROWS	4000000	Row ceiling per external-sort chunk.
AETHERIUS_PARTITIONED_TOPN	on	=0 disables the fused partitioned Top-N.
AETHERIUS_TOPN_COLUMNAR	on	=0 forces the row lane for Top-N.
AETHERIUS_TOPK	on	=0 disables the optimizer’s limit-pushdown Top-K rewrite.
AETHERIUS_FLAT_INDEX	on	=0 restores the tree path for PTI index maintenance.

Watchdog budgets

Setting	Default	What it does
--query-watchdog-ms N · AETHERIUS_QUERY_WATCHDOG_MS · AETHERIUS_QUERY_TIMEOUT_SECS	60000	Per-statement wall budget. 0 keeps disconnect cancellation but removes the deadline. Only consulted with the watchdog feature on.
--ddl-watchdog-ms N · AETHERIUS_DDL_WATCHDOG_MS · AETHERIUS_DDL_TIMEOUT_SECS	60000	Separate budget for DDL (index builds scale with data, not user patience).

Compute cells

Setting	Default	What it does
--external-fleet-endpoint S · AETHERIUS_EXTERNAL_FLEET_ENDPOINT	none	Worker binary path or pool-discovery URL. Only read with external cells on.
--cell-mode-strict · AETHERIUS_CELL_MODE_STRICT=1	off	Disable the in-process fallback; an external failure surfaces ResourceExhausted.
--cell-selection-policy P · AETHERIUS_CELL_SELECTION_POLICY	least-utilized	least-utilized, round-robin, least-rtt, consistent-hash.
--cell-local-fleet-workers N · AETHERIUS_CELL_LOCAL_FLEET_WORKERS	1	Run the fleet’s dispatch across N in-process lanes on this host.
--cell-warm-pool-size N · AETHERIUS_CELL_WARM_POOL_SIZE	2 × cores	In-process warm-cell pool size.
--cell-idleness-tick-ms N · AETHERIUS_CELL_IDLENESS_TICK_MS	1000	Idleness sweep cadence. 0 disables the ticker.
--cell-hot-idle-ms N · AETHERIUS_CELL_HOT_IDLE_MS	5000	HOT → HIBERNATED threshold.
--cell-cold-idle-ms N · AETHERIUS_CELL_COLD_IDLE_MS	60000	HIBERNATED → COLD threshold.
--cell-binary PATH / --socket-dir PATH	none	Cell binary and control-socket directory for --deployment-mode multi.
--cell-memory-pool-bytes N	0 (off)	Shared memory-pool size for the hypervisor’s memory fabric.
--cell-min-memory-bytes N	67108864 (64 MiB)	Minimum per-cell budget when the fabric is on.

Cluster

Setting	Default	What it does
AETHERIUS_TOPOLOGY_JSON	unset	Topology document inline (highest precedence).
AETHERIUS_TOPOLOGY_FILE	cluster-topology.json in the data dir	Topology file path.
AETHERIUS_REQUIRE_TOPOLOGY	off	=1 fails boot when cluster mode is requested and no topology loads, instead of degrading with a diagnostic.
AETHERIUS_WORKER_PORT	5434	Worker listening port.
AETHERIUS_WORKER_DATA_DIR	unset	The containers/ directory the worker serves. Unset: serves no data.
AETHERIUS_MAX_CONCURRENT_QUERIES_PER_TENANT	50	In-flight statements per tenant at the orchestrator.
AETHERIUS_TX_TIMEOUT	5000	Milliseconds a cluster transaction may stay open.
AETHERIUS_VACUUM_INTERVAL	60	Seconds between a worker’s vacuum sweeps.
--raft-peers 2,3 / --node-id N	empty / 0	Peer ids and this node’s id for the Raft metadata cluster.

Correctness and diagnostics

Setting	Default	What it does
AETHERIUS_REFERENCE_SCAN	off	=1 disables every plan-replacing accelerator so a query runs on the naive oracle path. Use it to diff a suspicious result.
AETHERIUS_VERIFY_EMPTY	off	=1 re-checks any zero-row or zero-aggregate SELECT against the naive path and returns the verified answer.
AETHERIUS_POINT_LOOKUP_STRICT	off	=1 turns every silent empty point lookup into a named error.
AETHERIUS_POINT_LOOKUP_ALLOW_SCAN	off	Test lever: allow the debug-build scan fallback in point lookups.
AETHERIUS_SCAN_STRICT	off	=1 errors when a sidecar-clean table takes the Arrow scan path.
AETHERIUS_SERVE_DEBUG	off	Set (any value) to print serve-path fallbacks to stderr.
AETHERIUS_OP_TIMING	off	=1 enables per-operator section timers (read once per process).
AETHERIUS_PARALLEL_SCAN_DEBUG_MAIN / AETHERIUS_PARALLEL_AGG_DEBUG_MAIN	off	Bisect levers: run the parallel partitioning on the calling thread.
AETHERIUS_VERIFY_DATASET	unset	Path for the ignored dataset-verification test.

Other binaries

Variable	Binary	What it does
AETHERIUS_NATIVE_AUTH_TOKEN / AETHERIUS_FLIGHT_AUTH_TOKEN	aesql	Token the CLI presents when connecting (same names the daemon reads).
AETHERIUS_MCP_MODE	aetherius-mcp	read_only (default), write, or admin tool set.
AETHERIUS_LICENSE_SIGNING_KEY	aether-license-keygen	Vendor signing seed. Never set on a database host.
AETHERIUS_LLM_DIR	aether-transmute-model	Local model directory for the live inference test.

AETHERIUS_BUILD_TS_NS is stamped into the binary at compile time and is not a runtime setting. Variables prefixed PHASE6_, AE_P44_DEBUG, AETHER_SPECTRAL_*, AETHER_WASM_STRING and AETH_RECOVER_DBDIR are developer bisect levers and ignored tests; they are not supported operator controls.

SQL SET variables

SET name = value and SHOW name work on every protocol. Any name is stored on the session and echoed back by SHOW; three names change behaviour.

Name	Values	Effect
query_mode	sql (default), aether-script / native / as, dual / dual-verify / both	Language the session’s statements are parsed as. dual runs both engines and compares.
statement_timeout	<n>ms, <n>s, <n>min, or a bare integer in ms	Per-session statement deadline. Requires the query watchdog to be on to be enforced.
branch	a branch name	Switch the session to a database branch.

SHOW current_user, session_user and user return the session’s principal.

Library-only RuntimeConfig fields

Embedders constructing aetherius_runtime::Runtime directly can set every field of RuntimeConfig. The daemon exposes 33 of them through the switches above; the rest hold their library default on a shipped aetheriusd and cannot be changed without a code change. They are listed so nobody hunts for a flag that does not exist. Most are feature gates for subsystems not yet surfaced.

Field	Library default	Purpose
enable_transmute	false	AI Legacy-Transmuter migration pipeline.
enable_lexicon_sidecar	false	Auto <col>_lex_id sidecar per text column.
enable_sorted_id_sidecar	false	Auto <col>_sorted_id sidecar for SORTED DOMAIN columns.
enable_dict_encode_text	false	Dictionary-encode Utf8 columns at scan output.
enable_lazy_boot_attach	false	Attach sealed cubes from containers at boot instead of re-inserting rows.
enable_graph_algebra	false	In-memory BFS / SSSP / PageRank primitives.
enable_auto_mv_advisor	false	Workload-driven materialization advisor.
enable_vector_trap	false	Page-fault to async-yield vector trap.
enable_yield_sensors	false	Pipeline memory/CPU pressure sensors.
enable_aggregate_pushdown	false	Aggregate pushdown via PTI branch mirrors.
enable_prefetch	false	Cooperative ACube prefetch engine.
enable_spectral_fk	true	Spectral (eventually-consistent) foreign keys.
enable_sublimation	false	ACube HOT → SUBLIMATED lifecycle.
enable_tokenizer	false	BPE / WordPiece tokenizer functions.
enable_epoch_scan_gating	false	Derive the slab allow-list from the epoch snapshot after RESTORE.
enable_flow_kafka / enable_flow_cloud	false	Kafka and S3/GCS/Azure source-connector drivers. Without them START SOURCE only flips a flag.
enable_telemetry	false	Live telemetry ring for the Studio profiler.
enable_rl_optimizer_train / enable_rl_plan_selection	false	PPO training thread; let the trained agent pick the plan.
enable_cognitive_jit	false	Lower natural-language DAGs to executable plans.
enable_gpu_execute / enable_gpu	false	GPU vector search (needs the gpu-wgsl build feature) / GPU dispatch.
htap_loom_interval_ms / htap_loom_flush_threshold_bytes	100 / 12 MiB	HTAP Loom ticker cadence and flush threshold (settings).
horizon_tick_interval_ms / max_promotions_per_tick	60000 / 64	UDRF horizon daemon cadence and per-tick cap (settings).
enable_compaq_daemon / compaq_tick_interval_ms	false / 30000	Background compaction daemon.
enable_auto_pulse / auto_pulse_interval_ms	false / 100	Epoch-snapshot auto-pulse ring producer.
udrf_l1_capacity_bytes	512 MiB	UDRF RAM tier capacity (setting).
default_schema	public	Schema for unqualified names (setting).
flush_policy	default	Chrono-Stripe flush policy (setting).
query_timeout_ms	30000	Dead. Read by nothing; use the watchdog.
enable_cluster, enable_lease, enable_fabric, enable_steal, enable_encrypt, enable_crdt, enable_topology, enable_void, enable_multimodal, enable_probe, enable_brain, enable_finops, enable_migrator, enable_script, enable_fractal	false	Closure adapters for distributed, fabric, encryption, multimodal, FinOps, migration and scripting subsystems.
enable_temporal, enable_lexicon	true	System-versioned temporal tables; semantic string dictionary.

Two defaults differ between library and daemon

enable_optimizer and enable_htap default to true in RuntimeConfig but the daemon sets them from its flags, so on a plain aetheriusd both are off until --enable-optimizer / --enable-htap is passed. Conversely cell_wasm_aggregates is false in the library and on in the daemon. When in doubt, read the boot banner, not the struct.

Configuration & Availability →

The curated flag list that feature pages cite.

Licensing & the license.key File →

What the license gates and how to verify it.

Install & Run →

Where the service unit and data directory live after install.

EXPLAIN →

See which join and scan routes a query actually took.

Cluster Execution Engine →

Orchestrator, workers and topology in depth.