implemented a lot of features

config/database.ts

@@ -61,7 +61,13 @@ const dbConfig = defineConfig({
         user: env.get('DB_USER'),
         password: env.get('DB_PASSWORD')?.release(),
         database: env.get('DB_DATABASE'),
+        // For idempotent bulk writers (worker:fetch): don't wait for the WAL
+        // flush on every statement. A crash loses the last moments of writes,
+        // which the retried job writes again.
+        ...(env.get('DB_SYNCHRONOUS_COMMIT') === 'off' ? { options: '-c synchronous_commit=off' } : {}),
       },
+      // One connection per concurrent job; knex defaults to 10.
+      pool: { min: 0, max: env.get('DB_POOL_MAX', 10) },
       migrations: {
         naturalSort: true,
         paths: ['database/migrations'],