Database queries page

performance/database-queries/ — where database cost concentrates and which endpoints are query-heavy or database-bound. See Database cost for how query count, DB time and DB % are measured.

KPI tiles

The build_kpis(since) tiles, with the database ones most relevant here: avg DB queries per request, avg response time, avg DB time and DB %.

Endpoint DB cost table

One row per endpoint (paginated, 20 per page), sorted by average queries descending:

Column	Source
Avg queries	Avg(db_query_count)
Max queries	Max(db_query_count)
Avg DB time	Avg(db_time_ms)
Max DB time	Max(db_time_ms)
DB %	avg_db_ms / avg_response_ms × 100

DB % is the tell: a high value means the endpoint's time is dominated by the database, so query optimisation will move the needle; a low value means the latency is elsewhere.

Query-count histogram

Up to 5,000 recent db_query_count values bucketed into 12 bins from 0 to the maximum observed. A long right tail, or a spike at a high bin, points at endpoints issuing far more queries than typical — usually an N+1 pattern.

DB time vs response time (scatter)

Up to 500 recent requests plotting db_time_ms (x) against response_time_ms (y). Points near the diagonal are database-bound (most of their time is queries); points well above it spend their time outside the database.

Slow requests

The 12 slowest requests in the range (response_time_ms ≥ 500, ordered descending), each with its endpoint, response time, query count, DB time, concurrency and a computed DB % for the individual request. This is the "show me the worst offenders right now" list.

DB offenders

Endpoints ranked by estimated total DB time contribution, not average per request — see DB offenders. The ranking is Σ(weight × db_time_ms) per endpoint with a share_pct of the grand total, so a cheap-but-constant endpoint that runs millions of times surfaces above a slow endpoint that runs rarely. This is the list to work down when you want the largest total database saving.

Refresh endpoint

performance/api/db-queries/ returns the page context as JSON, staff-only.