hareshkh opened a new pull request, #21121:
URL: https://github.com/apache/datafusion/pull/21121
## Which issue does this PR close?
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- Closes #.
## Rationale for this change
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the issue then this section is not needed.
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When a Substrait join expression contains both equal and
is_not_distinct_from predicates (e.g. Spark pushes a null-safe filter into a
join that already has a regular equality key), the
split_eq_and_noneq_join_predicate_with_nulls_equality function uses a single
nulls_equal_nulls boolean that gets overwritten per-predicate. Whichever
operator is processed last determines the NullEquality for all keys, silently
dropping NULL-matching rows.
Since NullEquality is a join-level setting (not per-key) across all physical
join implementations (HashJoinExec, SortMergeJoinExec, SymmetricHashJoinExec),
the correct fix is to match DataFusion's own SQL planner behavior: demote IS
NOT DISTINCT FROM keys to the join filter when mixed with Eq keys. This is
already correctly handled for SQL as shown in
[join_is_not_distinct_from.slt:L188](https://sourcegraph.com/r/github.com/apache/datafusion@2b7d4f9a5b005905b23128274ad37c3306ffcd15/-/blob/datafusion/sqllogictest/test_files/join_is_not_distinct_from.slt?L188)
```
# Test mixed equal and IS NOT DISTINCT FROM conditions
# The `IS NOT DISTINCT FROM` expr should NOT in HashJoin's `on` predicate
query TT
EXPLAIN SELECT t1.id AS t1_id, t2.id AS t2_id, t1.val, t2.val
FROM t1
JOIN t2 ON t1.id = t2.id AND t1.val IS NOT DISTINCT FROM t2.val
----
logical_plan
01)Projection: t1.id AS t1_id, t2.id AS t2_id, t1.val, t2.val
02)--Inner Join: t1.id = t2.id Filter: t1.val IS NOT DISTINCT FROM t2.val
03)----TableScan: t1 projection=[id, val]
04)----TableScan: t2 projection=[id, val]
```
## What changes are included in this PR?
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`datafusion/substrait/src/logical_plan/consumer/rel/join_rel.rs`:
- Collect eq_keys and indistinct_keys separately instead of using a single
vec with an overwritable boolean
- When both are present (mixed case), use eq_keys as equijoin keys with
NullEqualsNothing and reconstruct the IsNotDistinctFrom expressions into the
join filter
- Return NullEquality directly instead of converting from bool
## Are these changes tested?
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Yes, three levels of coverage:
1. Unit tests (join_rel.rs) — directly assert the output of
split_eq_and_noneq_join_predicate_with_nulls_equality for eq-only,
indistinct-only, mixed, and non-column-operand cases
2. Integration test (consumer_integration.rs) — loads a JSON-encoded
Substrait plan with a JoinRel containing both operators through
from_substrait_plan, executes it, and asserts 6 rows (including NULL=NULL
matches)
3. Existing SLT (join_is_not_distinct_from.slt:179-205) — confirms the SQL
planner already exhibits the same demotion behavior that this PR adds to the
Substrait consumer
## Are there any user-facing changes?
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updated before approving the PR.
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change` label.
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No API changes. Substrait plans with mixed equal/is_not_distinct_from join
predicates now correctly preserve null-safe semantics instead of silently
dropping NULL-matching rows.
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