diff --git a/backend/drizzle/0005_flow_facts.sql b/backend/drizzle/0005_flow_facts.sql
index d352fe2..577a2f7 100644
--- a/backend/drizzle/0005_flow_facts.sql
+++ b/backend/drizzle/0005_flow_facts.sql
@@ -1,5 +1,6 @@
 -- Statistics cube: hour + daily facts (server × iface × country × service × ASN).
--- Compact types, fillfactor for HOT upserts, autovacuum tuned for ON CONFLICT.
+-- Compact types. FILLFACTOR/autovacuum нельзя на partitioned parent (PG 42809) —
+-- задаются на листовых партициях в ensurePartitionFor.
 -- Retention: DROP partitions only (see PARTITION_SPECS).
 
 CREATE TABLE IF NOT EXISTS flow_hour_facts (
@@ -14,12 +15,6 @@ CREATE TABLE IF NOT EXISTS flow_hour_facts (
   PRIMARY KEY (server_id, bucket_at, iface, country, service, asn)
 ) PARTITION BY RANGE (bucket_at);
 
-ALTER TABLE flow_hour_facts SET (
-  fillfactor = 70,
-  autovacuum_vacuum_scale_factor = 0.05,
-  autovacuum_vacuum_cost_limit = 2000
-);
-
 CREATE TABLE IF NOT EXISTS flow_daily_facts (
   server_id BIGINT NOT NULL REFERENCES servers(id) ON DELETE CASCADE,
   day DATE NOT NULL,
@@ -31,9 +26,3 @@ CREATE TABLE IF NOT EXISTS flow_daily_facts (
   packets BIGINT NOT NULL DEFAULT 0,
   PRIMARY KEY (server_id, day, iface, country, service, asn)
 ) PARTITION BY RANGE (day);
-
-ALTER TABLE flow_daily_facts SET (
-  fillfactor = 70,
-  autovacuum_vacuum_scale_factor = 0.05,
-  autovacuum_vacuum_cost_limit = 2000
-);
diff --git a/backend/src/db/partitions.ts b/backend/src/db/partitions.ts
index 0333661..d46d51b 100644
--- a/backend/src/db/partitions.ts
+++ b/backend/src/db/partitions.ts
@@ -8,6 +8,12 @@ export interface PartitionSpec {
   keepDays: number
 }
 
+/** Leaf-only: PG forbids storage params on partitioned parents (SQLSTATE 42809). */
+const FACT_LEAF_STORAGE =
+  "fillfactor = 70, autovacuum_vacuum_scale_factor = 0.05, autovacuum_vacuum_cost_limit = 2000"
+
+const FACT_PARENTS = new Set(["flow_hour_facts", "flow_daily_facts"])
+
 export const PARTITION_SPECS: PartitionSpec[] = [
   { parent: "flow_buckets", kind: "day", keepDays: 4 },
   { parent: "flow_minute_stats", kind: "day", keepDays: 4 },
@@ -112,6 +118,9 @@ export async function ensurePartitionFor(
   await pool.query(
     `CREATE TABLE IF NOT EXISTS ${name} PARTITION OF ${parent} FOR VALUES FROM ('${from}') TO ('${to}')`,
   )
+  if (FACT_PARENTS.has(parent)) {
+    await pool.query(`ALTER TABLE ${name} SET (${FACT_LEAF_STORAGE})`)
+  }
   return name
 }