缓存并跳过未改变的步骤
只重新运行实际发生变化的部分，提高速度
缓存并跳过未改变的步骤 是 CoddyKit 上的免费 MLOps Academy 课时。 这是第 3 节课，共 4 节。 你可以在下方免费阅读本课时的完整内容 — 然后在浏览器中使用内置代码编辑器和全天候 AI 导师进行实践。 这是 MLOps Academy 学习路径的一部分，你的进度在网页和 CoddyKit 应用中同步。 MLOps Academy 课程共包含 4 节课。
本课时的部分内容尚未翻译，以英文显示。
Why Re-Run Everything?
If you only tweak the eval script, re-running ingest and train wastes time. DVC caches stage results so unchanged work is skipped. ⏱️
DVC Hashes Your Inputs
For each stage, DVC computes a hash of its dependencies and command. The hash is a fingerprint that changes the moment any input changes.
Same Hash Means Skip
When you run dvc repro, DVC compares each stage's current hash to the one in dvc.lock. If they match, it skips the stage.
See the Skip in the Output
DVC tells you plainly when nothing changed. A message like didn't change, skipping means the cached output was reused.
$ dvc repro
Stage 'prep' didn't change, skipping
Running stage 'train'...Changes Cascade Downstream
Change a prep input and DVC re-runs prep, then every downstream stage that depends on it. Upstream stages stay cached.
Outputs Are Stored in the Cache
Stage outputs are saved in DVC's cache directory, keyed by hash. Skipping a stage means DVC just restores that cached file.
Force a Full Re-Run
Need to ignore the cache? Pass --force to dvc repro and every stage runs again, even if nothing changed.
dvc repro --forceRe-Run a Single Stage
You can target one stage by name with dvc repro -s. Handy when you want to rerun just train without touching the rest.
dvc repro -s trainCheck Status Before Running
Run dvc status to see which stages are out of date without executing anything. It is a safe dry run of what repro would do.
dvc statusThe Speed Payoff
On big datasets, caching turns a thirty-minute pipeline into seconds when only one stage changed. That fast feedback loop is the whole point. ⚡
Commit dvc.lock to Share Cache State
Because dvc.lock holds the hashes, committing it lets teammates reuse the same cache decisions and skip work you already did.
Quick Check
Think about what triggers a re-run.
Recap: Cache and Skip
You saw how DVC hashes inputs to skip unchanged stages, cascade changes downstream, and force reruns when needed. Fast, smart pipelines. 🎯
常见问题解答
「缓存并跳过未改变的步骤」课时是免费的吗？
是的 — 「缓存并跳过未改变的步骤」的完整文本可在网页上免费阅读。要进行交互式练习（内置代码编辑器和全天候 AI 导师）并解锁 MLOps Academy 课程的其余内容，请升级到 CoddyKit PRO。 MLOps Academy 课程共包含 4 节课。
「缓存并跳过未改变的步骤」这节课中我会学到什么？
只重新运行实际发生变化的部分，提高速度 你通过在浏览器中直接运行的动手代码来练习 MLOps Academy，全天候 AI 导师会在你学习这节课的过程中回答你的问题。
学习 MLOps Academy 需要有经验吗？
无需任何先前经验。CoddyKit 上的 MLOps Academy 课程适合初学者到高级学习者，你可以从这里开始或从头开始，按照自己的节奏学习。 这是第 3 节课，共 4 节。
「缓存并跳过未改变的步骤」课时需要多长时间？
大多数 CoddyKit 课程大约需要 5–10 分钟。每节课都很精短且互动，所以你能稳步进步，并在网页和应用中从离开的地方继续。
我能在这节 MLOps Academy 课中编写并运行代码吗？
能。每节 MLOps Academy 课都包含内置代码编辑器，你可以在浏览器中直接编写并运行真实代码，并获得即时 AI 反馈 — 无需本地设置。