Implemented the DB index/query optimization

backend/src/db/migrations/20260702000001-add-asset-runtime-lookup-indexes.js

@@ -0,0 +1,36 @@
+'use strict';
+
+/**
+ * Add indexes for runtime transition asset lookups.
+ *
+ * Hot paths:
+ * - assets lookup by storage_key when resolving transition/reversed videos
+ * - asset_variants join/filter by assetId and variant_type for reversed variants
+ */
+
+module.exports = {
+  async up(queryInterface) {
+    await queryInterface.sequelize.query(`
+      CREATE INDEX IF NOT EXISTS assets_storage_key_active
+      ON assets (storage_key)
+      WHERE "deletedAt" IS NULL
+        AND storage_key IS NOT NULL
+    `);
+
+    await queryInterface.sequelize.query(`
+      CREATE INDEX IF NOT EXISTS asset_variants_asset_id_variant_type_active
+      ON asset_variants ("assetId", variant_type)
+      WHERE "deletedAt" IS NULL
+    `);
+  },
+
+  async down(queryInterface) {
+    await queryInterface.sequelize.query(`
+      DROP INDEX IF EXISTS asset_variants_asset_id_variant_type_active
+    `);
+
+    await queryInterface.sequelize.query(`
+      DROP INDEX IF EXISTS assets_storage_key_active
+    `);
+  },
+};

backend/src/db/models/asset_variants.ts

@@ -89,6 +89,13 @@ const defineAssetVariantsModel: SequelizeModelFactory = (
       timestamps: true,
       paranoid: true,
       freezeTableName: true,
+      indexes: [
+        {
+          fields: ['assetId', 'variant_type'],
+          name: 'asset_variants_asset_id_variant_type_active',
+          where: { deletedAt: null },
+        },
+      ],
     },
   );
 

backend/src/db/models/assets.ts

@@ -1,3 +1,5 @@
+import { Op } from 'sequelize';
+
 import type {
   SequelizeModel,
   SequelizeModelFactory,
@@ -133,6 +135,16 @@ const defineAssetsModel: SequelizeModelFactory = (sequelize, DataTypes) => {
       freezeTableName: true,
       indexes: [
         { fields: ['projectId'] },
+        {
+          fields: ['storage_key'],
+          name: 'assets_storage_key_active',
+          where: {
+            deletedAt: null,
+            storage_key: {
+              [Op.ne]: null,
+            },
+          },
+        },
         { fields: ['asset_type'] },
         { fields: ['type'] },
         { fields: ['is_public'] },