Fix nullable propagation in OR/IS NULL filters by MattAlp · Pull Request #142728 · elastic/elasticsearch

MattAlp · 2026-02-19T19:12:03Z

Summary

fix PropagateNullable so field IS NULL propagation substitutes null into matching expressions and folds, instead of nullifying entire expression branches
preserve correct semantics for predicates like (field IS NOT NULL OR p) AND field IS NULL, which previously could be rewritten to an always-empty filter
add regression coverage in local optimizer and PropagateNullable tests to prevent reintroducing the pruning
This patch was 'agentically' written based on a spec generated by fuzzing using ternary logic partitioning (TLP) - the fuzzing code is a Spacetime WIP

Preserve IS NULL filter semantics when OR branches reference the same field by substituting null into expressions and folding, instead of replacing entire branches with null. Co-authored-by: Cursor <cursoragent@cursor.com>

Use a reduced disjunction/nullability case and assert plan semantics rather than matching the original fuzz-generated query shape. Co-authored-by: Cursor <cursoragent@cursor.com>

Align the regression with the optimizer test suite pattern by using an explicit typed plan chain while still asserting both preserved conjuncts after optimization. Co-authored-by: Cursor <cursoragent@cursor.com>

...sql/src/test/java/org/elasticsearch/xpack/esql/optimizer/LocalLogicalPlanOptimizerTests.java

...c/test/java/org/elasticsearch/xpack/esql/optimizer/rules/logical/PropagateNullableTests.java

...ql/src/main/java/org/elasticsearch/xpack/esql/optimizer/rules/logical/PropagateNullable.java

julian-elastic

Overall the change looks good. I left some small suggestions to address before we check in.

julian-elastic · 2026-02-19T20:49:06Z

Also please add better comments in the PR with explanation.

Let A = field IS NOT NULL and B = p. Then field IS NULL = NOT A.
  The expression is:

  (A OR B) AND (NOT A)

  Distribute AND over OR:

  (A AND NOT A) OR (B AND NOT A)
    = FALSE     OR (B AND NOT A)
    = B AND NOT A

  Substitute back:

  p AND field IS NULL

Fix nullable propagation across OR disjunctions

fed4acf

Preserve IS NULL filter semantics when OR branches reference the same field by substituting null into expressions and folding, instead of replacing entire branches with null. Co-authored-by: Cursor <cursoragent@cursor.com>

elasticsearchmachine added the v9.4.0 label Feb 19, 2026

elasticsearchmachine and others added 4 commits February 19, 2026 19:18

[CI] Auto commit changes from spotless

67a9724

Refactor nullable propagation regression test

50ac6ea

Use a reduced disjunction/nullability case and assert plan semantics rather than matching the original fuzz-generated query shape. Co-authored-by: Cursor <cursoragent@cursor.com>

[CI] Auto commit changes from spotless

e920bd9

Refactor nullable propagation regression test

379663f

Align the regression with the optimizer test suite pattern by using an explicit typed plan chain while still asserting both preserved conjuncts after optimization. Co-authored-by: Cursor <cursoragent@cursor.com>