On 50,000 vectors of 768 dimensions on a 2-vCPU RDS instance, an exact nearest-neighbour search took 133 ms. HNSW cut it to 1.9 ms after a 47-second build; IVFFlat to 1.8 ms after 2.4 seconds. What recall looked like, why our numbers are a floor, and how to size this for real embeddings.
RDS Postgres 17 on db.m7g.large. Our measurements, November 2026.
The full report has p99 latencies, index sizes, measured recall at default settings, and why random test vectors understate recall compared with real embeddings.
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Database Failover Downtime on AWS, Measured: RDS Multi-AZ 13–15 Seconds, Aurora Under 2
We wrote to Postgres every 50 ms and forced failovers. RDS Multi-AZ lost writes for 13.0 and 14.8 seconds; in one trial the switch began three minutes after the reboot was requested. Aurora PostgreSQL lost writes for 2.0 and 0.5 seconds, one failed write each time. The full timelines, the errors your application will see, and what to set so it recovers on its own.
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Aurora Serverless v2, Measured: 14–21 Seconds to Resume From Zero, Two Minutes to Scale to 16 ACUs
With auto-pause at 0 ACUs, the first query after a pause took 21.4 and 13.6 seconds to answer. Under sustained CPU load, the cluster went from 2 ACUs to its 16-ACU maximum in about two minutes, and tail latency fell from 24 seconds to 5. What that means for scale-to-zero databases behind real users.
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As of November 9, 2026. Provided as is, for general information, and accurate to the best of our knowledge on the date shown. Not legal, compliance, tax, financial or other professional advice. Prices, limits and vendor services change; check current vendor documentation before relying on anything here. Terms of use.