--- title: Hardwood: A New Parser for Apache Parquet | daily.dev description: Hardwood is a new open-source Apache Parquet parser for Java 21+, built from scratch to address the heavy Hadoop dependency and single-threaded limitations of... canonical: https://daily.dev/posts/hardwood-a-new-parser-for-apache-parquet-ykkv3qu8e twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Hardwood: A New Parser for Apache Parquet | daily.dev og:description: Hardwood is a new open-source Apache Parquet parser for Java 21+, built from scratch to address the heavy Hadoop dependency and single-threaded limitations of... og:url: https://daily.dev/posts/hardwood-a-new-parser-for-apache-parquet-ykkv3qu8e og:image: https://api.daily.dev/og/posts/ykkv3QU8E.png og:image:alt: Hardwood: A New Parser for Apache Parquet 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. # Hardwood: A New Parser for Apache Parquet **[Hacker News](https://daily.dev/sources/hn)** · 8 min read · 1 upvotes · 0 comments ## Summary Hardwood is a new open-source Apache Parquet parser for Java 21+, built from scratch to address the heavy Hadoop dependency and single-threaded limitations of parquet-java. It offers two APIs: a row-oriented RowReader for complex nested schemas and a columnar ColumnReader for peak throughput via typed primitive arrays. Performance is achieved through page-level parallelism, adaptive page prefetching, cross-file prefetching, and minimizing allocations. Benchmarks show parsing ~9.2 GB of NYC taxi data (650M rows) in ~1.2 seconds using the column API on an M3 Max. The project is at 1.0.0.Alpha1, supports all column types and key encodings, with predicate push-down and a parquet-java compatibility layer on the roadmap. The author also shares candid reflections on using Claude Code as an AI assistant during development, emphasizing that LLM-generated code requires human review and ownership. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Improved Column Reader API, First Cut of Geospatial Support: Hardwood 1.0.0.CR1 Is Available](https://daily.dev/posts/improved-column-reader-api-first-cut-of-geospatial-support-hardwood-1-0-0-cr1-is-available-sophywvh1) · Gunnar Morling · 0 upvotes · 0 comments - [VARIANT Support, Interactive Parquet File TUI: Hardwood 1.0.0.Beta2 Is Out](https://daily.dev/posts/variant-support-interactive-parquet-file-tui-hardwood-1-0-0-beta2-is-out-fpq2dxjkd) · Gunnar Morling · 0 upvotes · 0 comments - [Chasing Efficient Java Development: From 1BRC to Developing Hardwood AI Natively](https://daily.dev/posts/chasing-efficient-java-development-from-1brc-to-developing-hardwood-ai-natively-oo495c7oo) · InfoQ · 0 upvotes · 0 comments - [Hardwood Reaches Beta: S3, Predicate Push-Down, CLI, and More](https://daily.dev/posts/hardwood-reaches-beta-s3-predicate-push-down-cli-and-more-qjzn498ft) · Gunnar Morling · 0 upvotes · 0 comments --- Tags: [#performance](https://daily.dev/tags/performance), [#java](https://daily.dev/tags/java), [#data-engineering](https://daily.dev/tags/data-engineering), [#apache-iceberg](https://daily.dev/tags/apache-iceberg) [View this post on daily.dev](https://daily.dev/posts/hardwood-a-new-parser-for-apache-parquet-ykkv3qu8e) ```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":"Hardwood: A New Parser for Apache Parquet","url":"https://daily.dev/posts/hardwood-a-new-parser-for-apache-parquet-ykkv3qu8e","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/hardwood-a-new-parser-for-apache-parquet-ykkv3qu8e"},"datePublished":"2026-03-01T17:33:26.884Z","dateModified":"2026-03-01T17:33:50.738Z","description":"Hardwood is a new open-source Apache Parquet parser for Java 21+, built from scratch to address the heavy Hadoop dependency and single-threaded limitations of...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/2d9ee15419361a239d07038800a2b38e?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/2d9ee15419361a239d07038800a2b38e?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Hacker News","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Hacker News","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/hn","url":"https://daily.dev/sources/hn"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/hardwood-a-new-parser-for-apache-parquet-ykkv3qu8e","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":1},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"performance,java,data-engineering,apache-iceberg","timeRequired":"PT8M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Hacker News","item":"https://daily.dev/sources/hn"},{"@type":"ListItem","position":3,"name":"Hardwood: A New Parser for Apache Parquet"}]} ```