---
title: "D1"
description: "1 posts about D1, summarised, each linking to the original."
---

# D1
> 1 posts about D1, summarised, each linking to the original.

## Articles

### [Under the hood, off the hot path: How D1 scales to millions of databases](https://yomu.fyi/post/under-the-hood-off-the-hot-path-how-d1-scales-to-millions-of-databases.md)
- Company: [Cloudflare](https://yomu.fyi/company/cloudflare.md)
- Author: Lambros Petrou
- Published: Oct 13, 2026
- Type: Explainer

D1, Cloudflare’s serverless SQLite database, has seen 15x growth in live databases over the past year and scales by keeping query execution on the edge in Durable Objects, separate from the control plane’s metadata operations. The control plane uses an Edge API Worker with Hyperdrive to access Postgres clusters for transactional metadata, while Workers KV caches database-to-Durable-Object mappings for fast edge lookups. Database creation completes in about 1.6 seconds by generating a Durable Object ID, persisting metadata to Postgres, and storing the mapping in Workers KV, with the Durable Object lazily initialized on first query. Storage usage enforcement uses atomic counters in Workers KV that are checked locally on each query and updated asynchronously after execution, avoiding any central database round trip during the query. Precomputed aggregations for billing are stored in ClickHouse, and guiding principles such as eventual consistency and idempotency further reduce reliance on centralized components.