Issues

• Internal error: GROUP BY over UNION ALL fails when a branch projects coalesce(<nullable bool>, FALSE) (CSE rewrite is physically nullable)

  apache/datafusion#25978 · Filter by author paul-heyse opened on Oct 2, 2026

• Pre-select before cheap conjuncts when the undecided rows form a few long runs

  enhancement
  Feature

  apache/datafusion#25976 · Filter by author Abhisheklearn12 opened on Oct 2, 2026
  1

  

• Lambda examples in the SQL function docs fail with the default dialect

  apache/datafusion#25960 · Filter by author rawsun007 opened on Oct 2, 2026

• PiecewiseMergeJoin returns wrong results for List keys with NULL elements and fails on Struct keys

  bug
  Bug

  apache/datafusion#25957 · Filter by author SubhamSinghal opened on Oct 2, 2026
  1

• array_repeat fails on lists with non-nullable elements or a non-default element field name

  bug
  apache/datafusion#25950 · Filter by author neilconway opened on Oct 1, 2026
  1

  

• array_concat on nested lists panics or fails with type mismatch errors

  bug
  apache/datafusion#25948 · Filter by author neilconway opened on Oct 1, 2026

• nvl / ifnull convert decimals to Float64 and timestamps and dates to strings

  bug
  apache/datafusion#25947 · Filter by author neilconway opened on Oct 1, 2026

• decimal % 1 returns 0 for non-nullable decimal columns

  bug
  apache/datafusion#25946 · Filter by author neilconway opened on Oct 1, 2026

• SQL unparser drops the time zone from timestamp literals

  bug
  apache/datafusion#25945 · Filter by author neilconway opened on Oct 1, 2026

• Queries with multiple SUM(expr + literal) aggregates fail or change result type

  bug
  apache/datafusion#25943 · Filter by author neilconway opened on Oct 1, 2026

• Spark negative returns wrong results for decimal columns

  bug
  apache/datafusion#25942 · Filter by author neilconway opened on Oct 1, 2026
  1

  

• Comparing a timestamp cast to a time zone against a literal returns wrong results

  bug
  apache/datafusion#25941 · Filter by author neilconway opened on Oct 1, 2026

• Option to assign Parquet row groups to file ranges by midpoint, as Spark does

  enhancement
  apache/datafusion#25938 · Filter by author comphead opened on Oct 1, 2026
  

• datafusion-proto: EmptyRelation loses its schema on a logical plan round trip

  bug
  Bug

  apache/datafusion#25937 · Filter by author bigluck opened on Oct 1, 2026
  1

  

• Grouped count(DISTINCT x) on numbers takes a slower path

  apache/datafusion#25936 · Filter by author mkleen opened on Oct 1, 2026
  1

  

• Record whether a window frame was set explicitly, so ExprFunctionExt can build on an existing window function

  apache/datafusion#25934 · Filter by author timsaucer opened on Oct 1, 2026

• sum(DISTINCT x) with GROUP BY uses twice the memory or more

  apache/datafusion#25932 · Filter by author mkleen opened on Oct 1, 2026
  4

• Implement optimizer hook for combining partial/final aggregate in AggregateExec

  enhancement
  Feature

  apache/datafusion#25928 · Filter by author 2010YOUY01 opened on Oct 1, 2026
  

• Avoid redundant sorts for scalar subquery expressions

  apache/datafusion#25926 · Filter by author Toby1009 opened on Oct 1, 2026
  2

• Add checked time arithmetic regression coverage for scalar UDF type recovery

  apache/datafusion#25925 · Filter by author Toby1009 opened on Oct 1, 2026
  1

  

• Filtered semi/anti sort-merge join is slow on small key groups and charges each group a whole batch

  apache/datafusion#25923 · Filter by author dwsmith1983 opened on Oct 1, 2026
  1

• Add a security policy

  enhancement
  Feature

  apache/datafusion#25916 · Filter by author alamb opened on Sep 30, 2026
  

• Spark xxhash64 hashes the raw bits of a NaN instead of the canonical NaN

  bug
  apache/datafusion#25913 · Filter by author andygrove opened on Sep 30, 2026

• Planning time grows quadratically with IN-list size on main

  bug
  Bug

  apache/datafusion#25905 · Filter by author gafiatulin opened on Sep 30, 2026

• feat: make SharedCoalescer do memory accounting for buffered batches

  enhancement
  Feature

  apache/datafusion#25904 · Filter by author gruuya opened on Sep 30, 2026
  1