Reuse fixed SQL statements for observation pruning

src/lib/server/hosts/index.ts

@@ -428,11 +428,11 @@ export function pruneHostObservations(): number {
         const rows = handle.prepare(`SELECT id FROM ec_host_operations WHERE observation_success=1 AND state='completed'
             AND updated_at<? ORDER BY updated_at LIMIT 500`).all(cutoff) as { id: string }[];
         if (!rows.length) return 0;
-        const ids = rows.map(row => row.id);
-        const placeholders = ids.map(() => '?').join(',');
-        handle.prepare(`DELETE FROM ec_host_operation_events WHERE operation_id IN (${placeholders})`).run(...ids);
-        handle.prepare(`DELETE FROM ec_host_operation_payloads WHERE operation_id IN (${placeholders})`).run(...ids);
-        return handle.prepare(`DELETE FROM ec_host_operations WHERE id IN (${placeholders})`).run(...ids).changes;
+        // Fixed SQL text prevents each batch size from adding three cached statements.
+        const ids = JSON.stringify(rows.map(row => row.id));
+        handle.prepare('DELETE FROM ec_host_operation_events WHERE operation_id IN (SELECT value FROM json_each(?))').run(ids);
+        handle.prepare('DELETE FROM ec_host_operation_payloads WHERE operation_id IN (SELECT value FROM json_each(?))').run(ids);
+        return handle.prepare('DELETE FROM ec_host_operations WHERE id IN (SELECT value FROM json_each(?))').run(ids).changes;
     })();
 }
 /** Heartbeats can tell an executing create to stop at its next safe command boundary. */