⚡ Bolt: [작업 목록 조회 성능 최적화를 위한 데이터베이스 인덱스 추가]

.jules/bolt.md

@@ -67,3 +67,6 @@
 ## 2025-02-12 - [Fast Path Execution in Directory Traversal and Log Parsing]
 **Learning:** Checking for string existence (`if "silence_" not in stderr`) before invoking regex matchers provides significant speed improvements when parsing large blocks of text. Similarly, moving expensive I/O operations like `os.path.realpath` inside conditional blocks prevents redundant disk access when configuration (like path exclusions) isn't utilized.
 **Action:** When working on large text processing or disk operations, verify if early exit conditions or conditional execution can bypass the expensive system or library calls.
+## 2023-11-20 - [SQLite job store query performance bottleneck]
+**Learning:** In a single-file SQLite database used as a job queue with a WAL journal mode, relying on full table scans for frequent `list_jobs` polling causes a measurable CPU and memory sorting (filesort) bottleneck. SQLite can quickly evaluate queries locally, but as row count scales to tens of thousands, scanning without an index becomes an issue.
+**Action:** When implementing an SQLite table meant to be polled or queried sequentially (e.g., a job table with status and timestamps), always define composite indexes corresponding to the `ORDER BY` and `WHERE` clauses from the start. Remember to use `conn.executescript()` instead of `conn.execute()` when initializing schemas with multiple statements.

CHANGELOG.md

@@ -4,3 +4,5 @@
 ### Added
 - 다중 파일 업로드 선택 시 즉각적인 파일 개수 피드백 및 제한 초과 경고 메시지 추가
 - 일괄 업로드 폼에 대상 바이트 프리셋 버튼과 총 파일 크기 미리보기를 추가하여 사용성을 개선했습니다.
+
+- `job_store.py` 데이터베이스 테이블에 조회 최적화를 위한 복합 인덱스를 추가하여 `list_jobs` 쿼리 성능 개선 (Bolt)

job_store.py

@@ -44,7 +44,12 @@
     output_name TEXT,
     error       TEXT,
     temp_dir    TEXT
-)
+);
+-- Bolt ⚡: Optimization for list_jobs queries.
+-- Composite indexes drastically speed up queries by preventing full table scans and memory file sorts
+-- when querying and ordering by status and created_at.
+CREATE INDEX IF NOT EXISTS idx_jobs_status_created_id ON jobs(status, created_at, id);
+CREATE INDEX IF NOT EXISTS idx_jobs_created_id ON jobs(created_at, id);
 """
 
 _COLUMNS = (
@@ -95,7 +100,7 @@ def __init__(self, db_path: str) -> None:
         self._db_path = str(db_path)
         self._lock = threading.Lock()
         with self._connect() as conn:
-            conn.execute(_SCHEMA)
+            conn.executescript(_SCHEMA)
 
     @contextmanager
     def _connect(self) -> Iterator[sqlite3.Connection]: