perf: add covering indexes for referral network queries

Add composite indexes on advertising_campaign_registrations(user_id,
created_at) and transactions(user_id, type, is_completed, amount_kopeks)
to enable index-only scans. Uses CREATE INDEX CONCURRENTLY for zero
downtime. Also enable transaction_per_migration in Alembic env.py.

app/database/models.py

@@ -1574,6 +1574,7 @@ class Transaction(Base):
         Index('ix_transactions_type_created_completed', 'type', 'created_at', 'is_completed'),
         Index('ix_transactions_user_created', 'user_id', 'created_at'),
         Index('ix_transactions_type_method_created', 'type', 'payment_method', 'created_at'),
+        Index('ix_transactions_user_type_completed_amount', 'user_id', 'type', 'is_completed', 'amount_kopeks'),
     )
 
     id = Column(Integer, primary_key=True, index=True)
@@ -2490,7 +2491,10 @@ class AdvertisingCampaign(Base):
 
 class AdvertisingCampaignRegistration(Base):
     __tablename__ = 'advertising_campaign_registrations'
-    __table_args__ = (UniqueConstraint('campaign_id', 'user_id', name='uq_campaign_user'),)
+    __table_args__ = (
+        UniqueConstraint('campaign_id', 'user_id', name='uq_campaign_user'),
+        Index('ix_campaign_reg_user_created', 'user_id', 'created_at'),
+    )
 
     id = Column(Integer, primary_key=True, index=True)
     campaign_id = Column(Integer, ForeignKey('advertising_campaigns.id', ondelete='CASCADE'), nullable=False)

migrations/alembic/env.py

@@ -45,7 +45,11 @@ def run_migrations_offline() -> None:
 
 
 def do_run_migrations(connection: Connection) -> None:
-    context.configure(connection=connection, target_metadata=target_metadata)
+    context.configure(
+        connection=connection,
+        target_metadata=target_metadata,
+        transaction_per_migration=True,
+    )
 
     with context.begin_transaction():
         context.run_migrations()

migrations/alembic/versions/0041_add_performance_indexes.py

@@ -0,0 +1,56 @@
+"""add performance indexes for referral network queries
+
+Revision ID: 0041
+Revises: 0040
+Create Date: 2026-03-20
+
+"""
+
+from typing import Sequence, Union
+
+from alembic import op
+
+revision: str = '0041'
+down_revision: Union[str, None] = '0040'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # CREATE INDEX CONCURRENTLY cannot run inside a transaction.
+    # autocommit_block() temporarily disables the transaction wrapper.
+    #
+    # NOTE: If a concurrent index creation fails midway, PostgreSQL leaves behind
+    # an INVALID index. Check with:
+    #   SELECT indexrelname FROM pg_stat_user_indexes
+    #   JOIN pg_index ON pg_index.indexrelid = pg_stat_user_indexes.indexrelid
+    #   WHERE NOT pg_index.indisvalid;
+    # Then drop the invalid index and re-run the migration.
+    with op.get_context().autocommit_block():
+        # Index on advertising_campaign_registrations(user_id, created_at)
+        # Fixes sequential scan in _fetch_campaign_registrations which filters by user_id
+        # and uses ROW_NUMBER() OVER (PARTITION BY user_id ORDER BY created_at)
+        op.create_index(
+            'ix_campaign_reg_user_created',
+            'advertising_campaign_registrations',
+            ['user_id', 'created_at'],
+            if_not_exists=True,
+            postgresql_concurrently=True,
+        )
+
+        # Covering composite index on transactions(user_id, type, is_completed, amount_kopeks)
+        # Enables index-only scans for aggregation queries in referral network stats:
+        # _fetch_personal_spent, _fetch_branch_revenue, _fetch_campaign_stats
+        op.create_index(
+            'ix_transactions_user_type_completed_amount',
+            'transactions',
+            ['user_id', 'type', 'is_completed', 'amount_kopeks'],
+            if_not_exists=True,
+            postgresql_concurrently=True,
+        )
+
+
+def downgrade() -> None:
+    with op.get_context().autocommit_block():
+        op.execute('DROP INDEX CONCURRENTLY IF EXISTS ix_transactions_user_type_completed_amount')
+        op.execute('DROP INDEX CONCURRENTLY IF EXISTS ix_campaign_reg_user_created')

uv.lock

@@ -1115,7 +1115,7 @@ wheels = [
 
 [[package]]
 name = "remnawave-bedolaga-telegram-bot"
-version = "3.33.0"
+version = "3.34.1"
 source = { virtual = "." }
 dependencies = [
     { name = "aiogram" },