278: WAL-ing Through Database Changes
Thinking Elixir Podcast
Practical Uses of WAL: Fly's Replication-Based RPC
Mark explains Fly's approach using WAL to block until replication completes, enabling consistent cross-region writes and reads.
News includes the Curiosum Elixir survey closing soon, ReqLLM reaching 1.0 with standardized LLM API support across multiple providers, Isaac Yonemoto's Codicil library bringing semantic code understanding to AI assistants through MCP, José Valim teasing Tidewave Web expansion to support Django, Rails, Next.js and other popular frameworks, phoenix_test_playwright adding browser pooling for improved performance, Peter Ullrich's deep dive into using Postgres WAL for database change notifications at scale, and more!
Show Notes online - http://podcast.thinkingelixir.com/278
Elixir Community News
- https://paraxial.io/ – Paraxial.io is sponsoring today's show! Sign up for a free trial of Paraxial.io today and mention Thinking Elixir when you schedule a demo for a special offer.
- https://elixir-survey.typeform.com/2025-edition – Curiosum Elixir survey open until November 14th, 2025 (about 2 days remaining when episode releases)
- https://elixir-hub.com/surveys – Where survey results will be published after the survey closes
- https://nitter.net/mikehostetler/status/1985134169899360709 – Announcement tweet about ReqLLM 1.0 release
- https://agentjido.xyz/blog/announcing-req_llm-1_0 – Blog post announcing ReqLLM 1.0, a Req-based package to standardize LLM API calls and responses across providers
- https://github.com/agentjido/req_llm – ReqLLM GitHub repository - went through 8 RCs to reach 1.0, includes Google Vertex AI, AWS Bedrock support, and more
- https://nitter.net/DNAutics/status/1983278808271663452 – Isaac Yonemoto's tweet about using an LLM to build an MCP to analyze and service Elixir codebases
- https://github.com/E-xyza/codicil/ – Codicil - Elixir library providing AI coding assistants with deep semantic understanding of your codebase through the Model Context Protocol
- Isaac will be speaking about Codicil at ExMex conference (which will have concluded by episode release)
- https://nitter.net/josevalim/status/1985408862690685315 – José Valim teases upcoming Tidewave Web expansion to support multiple frameworks including Django, FastAPI, Flask, Next.js, Phoenix, Rails, and React + Vite
- https://github.com/ftes/phoenix_test_playwright – phoenix_test_playwright library - executes PhoenixTest cases in actual browsers via Playwright
- https://github.com/ftes/phoenix_test_playwright/blob/main/CHANGELOG.md – Changelog for versions 0.9.0 and 0.9.1 with expanded click support, drag and drop, and browser pooling for reduced memory and higher speed
- https://github.com/ftes/phoenix_test_playwright/pull/86 – Pull request implementing browser pooling feature
- https://hexdocs.pm/phoenix_test – PhoenixTest documentation
- https://bsky.app/profile/peterullrich.com/post/3m4qms5kp322y – Peter Ullrich's Bluesky post about listening to database changes through Postgres WAL
- https://peterullrich.com/listen-to-database-changes-through-the-postgres-wal – In-depth blog post about using Postgres Write Ahead Log (WAL) for database change notifications at scale, avoiding pg_notify performance issues
- https://github.com/superfly/fly_rpc_elixir – fly_rpc Elixir library that uses WAL monitoring to track Postgres replication for distributed RPC calls across regions
Do you have some Elixir news to share? Tell us at @ThinkingElixir or email at show@thinkingelixir.com
Find us online
- Message the show - Bluesky
- Message the show - X
- Message the show on Fediverse - @ThinkingElixir@genserver.social
- Email the show - show@thinkingelixir.com
- Mark Ericksen on X - @brainlid
- Mark Ericksen on Bluesky - @brainlid.bsky.social
- Mark Ericksen on Fediverse - @brainlid@genserver.social
- David Bernheisel on Bluesky - @david.bernheisel.com
- David Bernheisel on Fediverse - @dbern@genserver.social
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