feat: Apply indexing to parameter-values (#50)

Author: anth-volk

src/policyengine_api/api/parameter_values.py

@@ -9,6 +9,7 @@
 from uuid import UUID
 
 from fastapi import APIRouter, Depends, HTTPException
+from fastapi_cache.decorator import cache
 from sqlmodel import Session, select
 
 from policyengine_api.models import ParameterValue, ParameterValueRead
@@ -18,6 +19,7 @@
 
 
 @router.get("/", response_model=List[ParameterValueRead])
+@cache(expire=3600)  # Cache for 1 hour
 def list_parameter_values(
     parameter_id: UUID | None = None,
     policy_id: UUID | None = None,

src/policyengine_api/modal_app.py

@@ -120,7 +120,6 @@ def simulate_household_uk(
 ) -> None:
     """Calculate UK household and write result to database."""
     import json
-    import os
     from datetime import datetime, timezone
 
     from rich.console import Console
@@ -246,7 +245,6 @@ def simulate_household_us(
 ) -> None:
     """Calculate US household and write result to database."""
     import json
-    import os
     from datetime import datetime, timezone
 
     from rich.console import Console

supabase/migrations/20251229000000_add_parameter_values_indexes.sql

@@ -0,0 +1,16 @@
+-- Add indexes to parameter_values table for query optimization
+-- This migration improves query performance for filtering by parameter_id and policy_id
+
+-- Composite index for the most common query pattern (filtering by both)
+CREATE INDEX IF NOT EXISTS idx_parameter_values_parameter_policy
+ON parameter_values(parameter_id, policy_id);
+
+-- Single index on policy_id for filtering by policy alone
+CREATE INDEX IF NOT EXISTS idx_parameter_values_policy
+ON parameter_values(policy_id);
+
+-- Partial index for baseline values (policy_id IS NULL)
+-- This optimizes the common "get current law values" query
+CREATE INDEX IF NOT EXISTS idx_parameter_values_baseline
+ON parameter_values(parameter_id)
+WHERE policy_id IS NULL;