1.2.0

Issues

• Sort-aware Iceberg reads: per-partition streaming merge + report ordering and grouping (v1)

  area:scanenhancement
  apache/datafusion-comet#5337 · Filter by author parthchandra opened on Aug 12, 2026 · 1.2.0
  

• Codegen dispatcher writes a null map key as the key type's default value

  area:expressionsbugpriority:critical
  apache/datafusion-comet#6172 · Filter by author Smallfu666 opened on Sep 24, 2026 · 1.2.0
  1

  

• NegativeExpr::get_properties reports child ordering and range unchanged

  area:expressionsbugpriority:medium
  apache/datafusion-comet#5330 · Filter by author Smallfu666 opened on Aug 11, 2026 · 1.2.0
  1

  

• Incorrect AVG result from empty native partial buffers

  area:aggregationbugpriority:medium
  apache/datafusion-comet#5418 · Filter by author sunchao opened on Aug 22, 2026 · 1.2.0
  1

• size, arrays_zip, map_from_arrays and array_append return wrong answers for a nondeterministic child

  area:expressionsarray expressionsbugcorrectnessmap expressionspriority:critical
  apache/datafusion-comet#5781 · Filter by author andygrove opened on Sep 8, 2026 · 1.2.0
  4

  

• Sliding-window SUM(BIGINT) ignores ANSI and TRY overflow semantics

  area:aggregationbugpriority:critical
  apache/datafusion-comet#6043 · Filter by author rich7420 opened on Sep 19, 2026 · 1.2.0
  1

  

• Write blog post for 1.1.0 release

  enhancement
  apache/datafusion-comet#6120 · Filter by author andygrove opened on Sep 22, 2026 · 1.2.0

• Comet 1.2.0 Release

  enhancement
  apache/datafusion-comet#6550 · Filter by author andygrove opened on Oct 2, 2026 · 1.2.0
  1

  

• My priorities for 1.2.0

  enhancement
  apache/datafusion-comet#6580 · Filter by author andygrove opened on Oct 3, 2026 · 1.2.0
  

• Native map construction doesn't match Spark 4.0+ float key normalization (-0.0 keys, missing DUPLICATED_MAP_KEY)

  area:expressionsbugpriority:critical
  apache/datafusion-comet#6549 · Filter by author andygrove opened on Oct 2, 2026 · 1.2.0
  

• Enable spark.comet.exec.localTableScan.enabled when running Spark SQL tests

  priority:lowspark sql tests
  apache/datafusion-comet#4347 · Filter by author mbutrovich opened on May 15, 2026 · 1.2.0
  1

• feat(iceberg): support HDFS storage via iceberg-rust hdfs-native backend [NOT FOR MERGE: pending apache/iceberg-rust#3111]

  area:Icebergarea:scanarea:shufflearea:writerenhancement
  Unread
  apache/datafusion-comet#5898·mixermt opened Sep 13, 2026 · Updated Oct 11, 2026·Draft
  2

• perf: every Comet broadcast hash join probe task re-decodes the whole broadcast in the JVM

  area:joinsenhancementperformance
  apache/datafusion-comet#6806 · Filter by author comphead opened on Oct 8, 2026 · 1.2.0
  2

  

• Write blog post for 1.2.0 release

  enhancement
  apache/datafusion-comet#6889 · Filter by author andygrove opened on Oct 12, 2026 · 1.2.0
  

• Native Iceberg scan returns wrong values for a column renamed after a VERSION AS OF snapshot

  area:Icebergarea:scanbugcorrectnesspriority:critical
  apache/datafusion-comet#6822 · Filter by author andygrove opened on Oct 9, 2026 · 1.2.0
  2

  

• Native Iceberg scan returns nested values that Spark reads as NULL in files without field ids or a name mapping

  area:Icebergarea:scanbugcorrectnesspriority:critical
  apache/datafusion-comet#6794 · Filter by author andygrove opened on Oct 8, 2026 · 1.2.0
  2

  

• Native Iceberg scan returns NULL for nested fields of migrated tables that use a name mapping

  area:Icebergarea:scanbugcorrectnesspriority:critical
  apache/datafusion-comet#6790 · Filter by author andygrove opened on Oct 8, 2026 · 1.2.0
  2

  

• Native hash joins lose the streamed side's order when it arrives sorted from outside the native plan

  bugcorrectnesspriority:critical
  apache/datafusion-comet#6787 · Filter by author dwsmith1983 opened on Oct 8, 2026 · 1.2.0
  2

  

• arrays_overlap returns wrong answers or panics with a constant array beside a column

  area:expressionsbugcorrectnesspriority:critical
  apache/datafusion-comet#6742 · Filter by author grorge123 opened on Oct 7, 2026 · 1.2.0
  

• [Bug] Native make_interval overflows valid time components or loses seconds precision

  area:expressionsbugpriority:medium
  apache/datafusion-comet#5131 · Filter by author peterxcli opened on Jul 29, 2026 · 1.2.0
  

• Native panic casting to negative-scale decimal when spark.sql.legacy.allowNegativeScaleOfDecimal=true

  area:expressionsbugcrashpriority:high
  apache/datafusion-comet#5013 · Filter by author andygrove opened on Jul 23, 2026 · 1.2.0
  3

  

• Register CometArrowAllocator as a Spark MemoryConsumer for JVM-UDF dispatch

  area:expressionsarea:ffipriority:medium
  apache/datafusion-comet#4174 · Filter by author andygrove opened on May 1, 2026 · 1.2.0
  1

  

• [Bug] map_from_arrays / map_from_entries do not enforce null-key rejection or spark.sql.mapKeyDedupPolicy

  area:expressionsbugcorrectnesspriority:medium
  apache/datafusion-comet#4680 · Filter by author andygrove opened on Jun 18, 2026 · 1.2.0
  3

  

• Drop support for Spark 3.4

  enhancementpriority:low
  apache/datafusion-comet#4329 · Filter by author andygrove opened on May 14, 2026 · 1.2.0
  3

• Native Iceberg writes do not use shuffle direct read for their input

  area:Icebergarea:shufflearea:writerenhancementperformancerequires-triage
  apache/datafusion-comet#6913 · Filter by author andygrove opened on Oct 12, 2026 · 1.2.0