Issues

• Readers: write flat rows directly, without per-row Python conversion

  datachain-ai/datachain#2119 · Filter by author dmpetrov opened on Oct 28, 2026

• Remove temporary pytest <9.2 bound after benchmark plugin updates

  datachain-ai/datachain#2113 · Filter by author shcheklein opened on Oct 27, 2026
  

• Keys with double-slash follow-ups

  bug
  datachain-ai/datachain#2086 · Filter by author dmpetrov opened on Oct 21, 2026

• UDFs speed up parallelism: one progress message, dynamic work distribution

  enhancement
  datachain-ai/datachain#2078 · Filter by author dmpetrov opened on Oct 19, 2026

• Listing: parallel key ranges on ADLS Gen2

  enhancement
  datachain-ai/datachain#2077 · Filter by author dmpetrov opened on Oct 18, 2026

• S3: _fetch_dir always asks for versions

  bug
  datachain-ai/datachain#2076 · Filter by author dmpetrov opened on Oct 18, 2026
  1

• versions=True can return a key twice as latest when it changes between two listing pages

  bug
  datachain-ai/datachain#2069 · Filter by author shcheklein opened on Oct 17, 2026

• GCS: a key that ends with '#' and digits, like dir/#0, reads as empty bytes

  bug
  datachain-ai/datachain#2066 · Filter by author shcheklein opened on Oct 17, 2026
  2

• Azure: a blob name that ends with '#' loses the '#', so the file can't be read

  bug
  datachain-ai/datachain#2065 · Filter by author shcheklein opened on Oct 17, 2026
  2

• UDF: a public row_type(model)

  datachain-ai/datachain#2057 · Filter by author dmpetrov opened on Oct 17, 2026

• Listing: S3 and Azure reads part of the bucket twice

  enhancement
  datachain-ai/datachain#2050 · Filter by author dmpetrov opened on Oct 15, 2026

• Listing: Validate destination paths in cp and pull --cp

  bug
  datachain-ai/datachain#2041 · Filter by author dmpetrov opened on Oct 12, 2026

• Listings: support object keys with a leading slash

  enhancement
  datachain-ai/datachain#2040 · Filter by author dmpetrov opened on Oct 12, 2026

• MCAP and LeRobot v3 readers

  enhancement
  datachain-ai/datachain#2023 · Filter by author dmpetrov opened on Oct 8, 2026

• read_parquet: predicate pushdown

  bugpriority-p2
  datachain-ai/datachain#2022 · Filter by author dmpetrov opened on Oct 8, 2026
  1

• Hydrate Pydantic models nested in collections when reading datasets

  datachain-ai/datachain#2007 · Filter by author ilongin opened on Sep 28, 2026
  

• Preserve aliases when hydrating nested Pydantic model collections

  datachain-ai/datachain#2003 · Filter by author ilongin opened on Sep 28, 2026
  

• Top-level Pydantic model unions read back as dictionaries

  datachain-ai/datachain#2002 · Filter by author ilongin opened on Sep 28, 2026

• Introducing URL type

  enhancement
  datachain-ai/datachain#1984 · Filter by author dmpetrov opened on Sep 9, 2026

• A model and a plain value serialize by different rules

  datachain-ai/datachain#1968 · Filter by author shcheklein opened on Aug 30, 2026

• Union types: collection arms (Union[str, list[str]])

  datachain-ai/datachain#1952 · Filter by author dmpetrov opened on Aug 24, 2026

• Unify deprecation warnings behind one helper

  datachain-ai/datachain#1950 · Filter by author dmpetrov opened on Aug 23, 2026

• Drop the legacy numeric _type_tag (arm index) layout

  datachain-ai/datachain#1949 · Filter by author dmpetrov opened on Aug 23, 2026
  1

• Validation accepts annotations that storage cannot honour

  datachain-ai/datachain#1942 · Filter by author shcheklein opened on Aug 19, 2026

• Read path: values do not come back as their declared type

  datachain-ai/datachain#1918 · Filter by author shcheklein opened on Aug 17, 2026