--- title: On rebuilding read models, Dead-Letter Queues and Why... description: A deep dive into a race condition discovered in event-driven read model rebuilding with PostgreSQL. The author walks through three failed attempts to prevent... canonical: https://daily.dev/posts/on-rebuilding-read-models-dead-letter-queues-and-why-letting-go-is-sometimes-the-answer-ytt74jgv4 twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: On rebuilding read models, Dead-Letter Queues and Why Letting Go is Sometimes the Answer | daily.dev og:description: A deep dive into a race condition discovered in event-driven read model rebuilding with PostgreSQL. The author walks through three failed attempts to prevent... og:url: https://daily.dev/posts/on-rebuilding-read-models-dead-letter-queues-and-why-letting-go-is-sometimes-the-answer-ytt74jgv4 og:image: https://api.daily.dev/og/posts/ytt74JGV4.png og:image:alt: On rebuilding read models, Dead-Letter Queues and Why Letting Go is Sometimes the Answer og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # On rebuilding read models, Dead-Letter Queues and Why Letting Go is Sometimes the Answer **[Event-Driven by Oskar Dudycz](https://daily.dev/sources/event-driven-io)** · 18 min read · 0 upvotes · 0 comments ## Summary A deep dive into a race condition discovered in event-driven read model rebuilding with PostgreSQL. The author walks through three failed attempts to prevent events from being skipped during inline projection rebuilds (waiting for in-flight transactions, using transaction ID boundaries, and locking appends), explaining why each fails due to PostgreSQL's transaction visibility rules. The solution reframes the problem: instead of preventing skips, record them as system messages in the same transaction, then drain and process them after the rebuild completes. This is essentially a Dead Letter Queue pattern applied to projection rebuilding. The broader lesson is that distributed systems have fundamental constraints that can't always be engineered around — accepting failures and making them visible and recoverable is often stronger than complex coordination machinery. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [On rebuilding read models, Dead-Letter Queues and Why Letting Go is Sometimes the Answer](https://daily.dev/posts/on-rebuilding-read-models-dead-letter-queues-and-why-letting-go-is-sometimes-the-answer-9srxnccwt) · Architecture Weekly · 4 upvotes · 0 comments - [Using PostgreSQL as a Dead Letter Queue for Event-Driven Systems](https://daily.dev/posts/using-postgresql-as-a-dead-letter-queue-for-event-driven-systems-ekm9n1imv) · Hacker News · 0 upvotes · 0 comments - [Rebuilding Event-Driven Read Models in a safe and resilient way](https://daily.dev/posts/rebuilding-event-driven-read-models-in-a-safe-and-resilient-way-v2gd5xsp0) · Architecture Weekly · 16 upvotes · 0 comments --- Tags: [#architecture](https://daily.dev/tags/architecture), [#postgresql](https://daily.dev/tags/postgresql), [#distributed-systems](https://daily.dev/tags/distributed-systems) [View this post on daily.dev](https://daily.dev/posts/on-rebuilding-read-models-dead-letter-queues-and-why-letting-go-is-sometimes-the-answer-ytt74jgv4) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"On rebuilding read models, Dead-Letter Queues and Why Letting Go is Sometimes the Answer","url":"https://daily.dev/posts/on-rebuilding-read-models-dead-letter-queues-and-why-letting-go-is-sometimes-the-answer-ytt74jgv4","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/on-rebuilding-read-models-dead-letter-queues-and-why-letting-go-is-sometimes-the-answer-ytt74jgv4"},"datePublished":"2026-06-17T11:26:18.771Z","dateModified":"2026-06-17T11:34:37.614Z","description":"A deep dive into a race condition discovered in event-driven read model rebuilding with PostgreSQL. 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