9 terms, written for people who did not build the thing.
Aggregation also called roll-up
Combining many rows into one figure — a sum, a count, an average. Every chart you see is an aggregation of something.
See also cardinality, dimension
Audit log
An append-only record of who did what and when. Nothing in it can be edited, including by us.
Backfill
Loading historical data into a new column or table after the fact, usually slowly and usually at night.
See also incremental sync
Burst capacity also called headroom
Short-lived allowance above your plan limit, so a launch day does not start returning errors.
Cardinality
How many distinct values a column holds. High cardinality makes charts unreadable and queries expensive.
Cursor
The marker a sync stores so the next run knows where it stopped. Usually an indexed timestamp.
Cache key
The fingerprint that decides whether two queries count as identical. Ours includes your access rules, so nobody sees a neighbour cached result.
Dimension
A column you group by rather than measure — region, plan, channel. Metrics are the numbers; dimensions are the slices.
Deprovisioning
Removing someone access automatically when your identity provider says they have left.