If you follow me on here, you should follow me on there: bsky.app/profile/julien.lede…

In SF during Snowflake Summit June 1-3? Duck out (ha!) to The Dive! Hear from rockstars at Anthropic, Braintrust, Lovable, Hex, & more. See the future of lakehouses with @J_ , creator of Apache Parquet, and @zeroshade, founder at Columnar (& me!) Register! thedive.motherduck.com/

@J_ & Pierre Lacave of @datadoghq on how they rely on and contribute to key projects in the data ecosystem: Arrow for data interchange Substrait for plans Calcite as an optimizer DataFusion as an execution core Parquet for columnar storage

Thank you for letting me keynote day 2 of the Iceberg summit. I hope you all enjoyed it! bsky.app/profile/julien.lede…

Hey it’s @J_ @ Iceberg Summit. Great keynote!!

@J_ this morning at #icebergsummit.

The database landscape is going through its biggest shift in a decade. AI workloads are pushing OLTP and OLAP closer together, object storage is becoming the de facto foundation for AI search at hundred‑billion‑ to trillion‑document scale, and agents are spinning up databases and schemas programmatically in patterns classic systems were never optimized for. AI Council's Data Engineering & Databases track is where the builders re-architecting the stack come together. Curated by @saisrirampur, Director of Product at @ClickHouseDB, here's the lineup: → Hannes Mühleisen, Co-Founder & CEO at @duckdb: "Super-Secret Next Big Thing for DuckDB" → @nikhilbenesch, CTO at @turbopuffer: "Fast AI Search on Object Storage @ >1 Trillion Scale" → @J_ & Pierre Lacave, Principal Engineer & Staff Engineer at @datadoghq: "The Deconstructed Database at Datadog" → @iskakaushik, Engineering Lead at ClickHouseDB: "Building a Unified OLTP OLAP Database for AI Workloads" → Bhargavi Reddy Dokuru, Staff Data Engineer at @netflix: "Democratizing Analytics via Self Service: Netflix Games Edition" → @kelvich, Principal Software Engineer at @databricks & Neon co-founder: "AI Needs a New Kind of OLTP: Lakebase & Serverless Postgres in the Agent Era" → Robin Tang, Co-founder & CTO at @artie_labs: “Scaling CDC to Trillions of Rows: What Broke, What We Rebuilt, and What AI Demands Next” A huge thank you to Sai for curating this awesome track! Join us SF, May 12-14! 🎟️ aicouncil.com

@J_ co-created Apache Parquet, Apache Arrow, and OpenLineage. Three projects. Three industry standards. Parquet at Twitter in 2013. Arrow at Dremio. OpenLineage at Datakin, acquired as part of Astronomer's $213M Series C. He is now Principal Engineer at Datadog and an officer of the Apache Software Foundation. That is an unusual track record of picking the right abstraction at the right time. His OpenXData talk argues that the current wave of challengers -- Lance, Vortex, Nimble, FastLanes, BtrBlocks, F3 -- are solving real problems but misreading what made Parquet succeed in the first place. The core contribution was not the encoding choices. It was the community consensus mechanism those choices were built inside. His case: use established open source communities to absorb these innovations rather than fragment the ecosystem across six competing formats. He published the written version of this argument at sympathetic.ink in December 2025. OpenXData is where you can push back live. 👉 Register here: openxdata.ai

If you follow me on here, you should follow me on there: bsky.app/profile/julien.lede…

If you missed my talk "The advent of the open data lake" at AI By the Bay, the recording is now available. ai.bythebay.io/talks/the-adv… youtube.com/watch?v=xHGVCVjA…

There is some crazy (good) activity on the @ApacheParquet mailing list for new encodings. A sample: PFOR, FSST, ALP, Strings and Cascaded Encodings. 🤯 Huge kudos to Arnav Balyan, Prateek Gaur, and Micah Kornfield for driving this. lists.apache.org/list.html?d…

If you missed me giving it live, the slides of my talk, "Column Storage for the AI era" are available here: docs.google.com/presentation…

I’ll be speaking in Mountain View on Thursday. Come say hi!

Higher latency but higher throughput on improving the overall data ecosystem.

Cool parquet metadata visualizer by @J_, powered by Hyparquet

If you've been wondering why we see a flurry of new columnar formats, come see me present "Column Storage for the AI Era". I'll talk about what has changed, new advances in data encoding and how that's pushing Parquet to evolve. Event tomorrow: luma.com/pxikwty3

New file format just dropped !

I'm trying to understand a bit better real life deployments of open source Clickhouse. If you're using it, what does your deployment look like?

The FastLanes format paper from @afroozeh3 and @peterabcz contains interesting and practical ideas for representing SIMD friendly cascaded encodings. I think almost all of the ideas could be applied to extend @ApacheParquet as a new encoding scheme. github.com/cwida/FastLanes/b…