artifact-data-loadinglisted

# Artifact data loading A page is one file with a 16MB ceiling and no network. So the question is never "how do I ship all the rows" — it is **"what is the smallest dataset that answers the question."** Almost always, the answer is far smaller than the raw data, and the reduction happens *before* embedding, not after. --- ## Aggregate at the source first The highest-leverage step, and it happens in SQL, not in the page. ```sql -- WRONG: 180,000 rows embedded so the page can group them SELECT * FROM gl WHERE period = '2026-07' -- RIGHT: 40 rows; the page renders, it does not compute SELECT account, account_name, SUM(amount) AS amount, COUNT(*) AS txn_count, SUM(amount) - SUM(prior_amount) AS variance FROM gl_with_prior WHERE period = '2026-07' GROUP BY account, account_name HAVING ABS(SUM(amount) - SUM(prior_amount)) > 25000 ``` Ship the grain the visual needs. A chart with 40 marks needs 40 rows — embedding 180,000 so the browser can produce those 40 is pure cost. **Ship a second, coarser aggregate for drill-down** rather than the detail: top 10 transactions per account, not every transaction. Full detail belongs behind a download. --- ## Choosing the grain Work backwards from the marks: | Visual | Rows needed | |---|---| | KPI tile | 1 | | Bridge / waterfall | one per bar (5-12) | | Monthly time series, 3 years | 36 per series | | Cohort heatmap, 24 ×