Glossary · Phase 11 · Professional practice
Upsert
An insert that updates the existing row when the key is already there, such as SQLite's INSERT ... ON CONFLICT DO UPDATE, so rerunning it never adds a duplicate.
Try it now
Unrated replies belong in the denominator: leaving them out makes the rate look far worse than it is.
Learn it properly
Measuring an AI feature from its logs · Typed views over event logs, metric specs, cost from a price table, and rollups you can rerun. About 40 minutes.
Other terms from the same lesson
- metric spec: A metric written down before it's computed: its numerator, denominator, what's left out and its unit.
- rollup table: A table of precomputed summaries, such as one row of metrics per day, rebuilt by a scheduled job so dashboards don't scan raw events.
- SQL view: A saved query that looks like a table. It stores no data, so it always shows the current rows underneath.
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Teach a small one to write, right in your browser. It takes about 20 seconds and needs no account.