- Add --append flag: diff source-table 总排号 against existing
Common.Attachment SN and classify/write only the missing ones. --limit
caps the per-run append count, --order sets the direction. Backed by
new fetch_existing_attachment_sns() in db.py.
- Fix batch elapsed-time accounting: summarize_results() summed each
task's per-item elapsed_ms, which overcounts under ThreadPoolExecutor
concurrency (cumulative work time, not real wall-clock — 100 tasks on
8 workers reported ~5x the actual runtime). Callers now time
classify_batch() via perf_counter and pass wall_clock_ms; both the
write_attachments [汇总] line and main.py --summary report wall-clock
separately from the cumulative sum.
- Format durations >=1s in seconds (88851.4 ms -> 88.85 s) in the
human-readable [汇总] line; structured JSON --summary fields stay in ms.
- Chunk all IN (...) lists to 2000 items to respect SQL Server's 2100
bind-parameter hard limit (previously --append --limit 5000 failed at
the fetch step with "COUNT 字段不正确"). Applied to fetch_params_by_ids
(sn / id paths) and to the DELETE inside upsert_attachments.
Co-Authored-By: Claude <noreply@anthropic.com>
