High-Throughput Database Considerations | Dataford Interview Questions

What are the critical considerations when working with databases in a high-throughput environment?

Use the query telemetry and query plan tables to produce a workload summary by endpoint and minute. Include performance, reliability, and plan-usage indicators that help identify operational concerns.

Output

One row per endpoint and minute.
Include endpoint, minute, query count, queries per second, p95 latency, error rate, average cache hit percentage, and observed index usage.
Order by endpoint, then minute ascending.

Schema

query_events

Column	Type	Description
event_idPK	INT	Unique query telemetry event identifier
endpoint	VARCHAR(100)	Logical workload endpoint
occurred_at	TIMESTAMP	Time when the query completed
latency_ms	INT	Query latency in milliseconds
status	VARCHAR(20)	Query completion status
rows_returned	INT	Number of rows returned by the query
plan_id	INT	Optional reference to the captured query plan

query_plans

Column	Type	Description
plan_idPK	INT	Captured query plan identifier
index_name	VARCHAR(120)	Index used by the plan, if any
cache_hit_pct	DECIMAL(5,2)	Percentage of reads served from cache
plan_type	VARCHAR(40)	General execution plan type

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Problem