At a glance
The percentage of SQL queries that failed rather than completed successfully, measured over a rolling five-minute window. This is the lakehouse’s “are queries working?” gauge. A small baseline of errors is normal (a user typos a column name, an ad-hoc query times out), but a sustained rate above 1% means something systemic is wrong: a table was dropped or renamed, a schema changed under a dashboard, the metastore is unreachable, or a warehouse is failing health checks. For a platform team this is a front-line outage detector, because a rising error rate is often the first thing that moves when an upstream change breaks downstream consumers.
Calculation
Over the trailing five-minute window, Vortex IQ reads the query-history feed for the monitored warehouses and classifies each terminal query as success or failure based on its final status:Worked example
A platform team runs a SQL warehouse serving about 60 analyst and dashboard queries per minute against a gold-layer schema. A data-engineering squad ships a model change at 13:00 UTC that renamesgold.customer_360.lifetime_value to ltv_gbp. Snapshot taken on 23 Apr 26 around the deploy.
At 13:01 the gauge jumps from 0.6% to 13.4% and pages the on-call. The error sample in the drill-down is unambiguous.
- Roll back the rename, then migrate forward. The fastest path to green is to revert the model change so consumers work again, then reintroduce the rename as an additive change (add
ltv_gbpas a copy, deprecatelifetime_value, update consumers, drop the old column later). The error rate returns to baseline by 13:20. - Identify every broken consumer from the failures. The drill-down already names the six dashboards and two exports that failed, which is the exact migration checklist. There is no need to guess which downstream objects referenced the column.
- Add a contract check to the deploy. A pre-deploy test that runs each known consumer query against the proposed schema would have caught this before it shipped. The error rate spike is the symptom; the missing schema-contract test is the root cause.
- Read the percentage with the absolute count. 13.4% on 305 queries is a real, broad outage. The same 13.4% on a warehouse doing five queries in five minutes would be a single unlucky ad-hoc query, not an emergency. The card shows both for exactly this reason.
- Error rate is the fastest deploy-regression detector you have. It moved within 60 seconds of the breaking change, faster than anyone filed a ticket. Pair it with your deploy timeline so a spike immediately points at the change that caused it.
Sibling cards
Reconciling against the source
Where to look in Databricks:
Open SQL → Query History and filter Status = Failed over a five-minute window; the failed count over the total is this card.
Run SELECT execution_status, count(*) FROM system.query.history WHERE start_time >= now() - interval 5 minute GROUP BY execution_status (where the system schema is enabled) for the success/failure split.
Each failed row in Query History exposes the error message and class, the same sample the card’s drill-down surfaces.
Why our number may legitimately differ from the Databricks UI:
Cross-connector reconciliation: