james-willis opened a new pull request, #58293:
URL: https://github.com/apache/spark/pull/58293

   ### What changes were proposed in this pull request?
   
   `InMemoryRelation.newInstance()` now goes through `withOutput`, so that 
`outputOrdering` is re-mapped onto the freshly-instantiated attributes instead 
of being carried over unchanged.
   
   `withOutput` is also made defensive: if `outputOrdering` references 
attributes that are not present in `output`, the ordering is dropped rather 
than the `AttributeMap` lookup throwing.
   
   ### Why are the changes needed?
   
   `InMemoryRelation` has an implicit invariant that `outputOrdering` may only 
reference attributes present in `output`. `newInstance()` violates it: it gives 
`output` fresh exprIds but passes `outputOrdering` through unchanged, so the 
returned relation's ordering still points at the old attributes.
   
   That was harmless until 
[SPARK-53738](https://issues.apache.org/jira/browse/SPARK-53738), which routed 
`doCanonicalize` through `withOutput` and made `withOutput` re-map the ordering 
with a strict `AttributeMap` lookup. Since then, any `InMemoryRelation` that 
has been through `newInstance()` fails as soon as anything canonicalizes it:
   
   ```
   java.util.NoSuchElementException: key not found: k#1L
     at scala.collection.MapOps.default(Map.scala:289)
     at 
org.apache.spark.sql.catalyst.expressions.AttributeMap.apply(AttributeMap.scala:41)
     at 
org.apache.spark.sql.execution.columnar.InMemoryRelation.$anonfun$withOutput$1(InMemoryRelation.scala:711)
     at 
org.apache.spark.sql.execution.columnar.InMemoryRelation.withOutput(InMemoryRelation.scala:711)
     at 
org.apache.spark.sql.execution.columnar.InMemoryRelation.doCanonicalize(InMemoryRelation.scala:672)
     ...
     at 
org.apache.spark.sql.execution.adaptive.AdaptiveSparkPlanExec.createNonResultQueryStages(AdaptiveSparkPlanExec.scala:589)
   ```
   
   This is reachable from ordinary SQL. Cache substitution 
(`CacheManager.useCachedData`) runs on the analyzed plan, before the optimizer. 
`InlineCTE` then inlines a CTE that is referenced more than once and, to get a 
fresh-exprId copy, runs `DeduplicateRelations` over a synthetic self-join. By 
that point the plan already contains the `InMemoryRelation`, which is a 
`MultiInstanceRelation`, so `newInstance()` is called on it.
   
   A user-facing repro — a persisted DataFrame with a global `ORDER BY`, 
window-ranked and then self-joined:
   
   ```python
   spark.range(0, 20).selectExpr("id", "id % 3 AS 
k").createOrReplaceTempView("t")
   
   b = spark.sql("SELECT id, k FROM t ORDER BY k, id")
   b.persist()
   b.count()
   b.createOrReplaceTempView("b")
   
   spark.sql("""
     WITH r AS (SELECT *, row_number() OVER (PARTITION BY k ORDER BY id DESC) 
AS rn FROM b)
     SELECT x.id AS p, y.id AS q
     FROM r x JOIN r y ON x.k = y.k AND x.rn = 1 AND y.rn = 2
   """).show()
   ```
   
   This fails on 4.0.2 and later. It succeeds on 4.0.1, which predates 
SPARK-53738. The user sees only an internal `NoSuchElementException` at the 
first action, with nothing actionable in it — the query itself is well formed. 
I verified the failure on 4.0.4, 4.1.3 and 4.2.0.
   
   See [SPARK-59009](https://issues.apache.org/jira/browse/SPARK-59009) for the 
full analysis.
   
   ### Does this PR introduce _any_ user-facing change?
   
   No, other than the bug fix itself: queries that reference a cached relation 
with a non-empty `outputOrdering` more than once now succeed instead of failing 
with an internal error.
   
   `newInstance()` also preserves the ordering now rather than returning a 
relation with a stale one, so the ordering remains usable as an optimization 
hint for the new instance.
   
   ### How was this patch tested?
   
   Two new tests, both of which fail on unmodified `master`:
   
   - `InMemoryRelationSuite`, a unit test asserting that after `newInstance()` 
the ordering references the new attributes and that the result canonicalizes 
without throwing. This one pins the `newInstance()` behaviour specifically: it 
still fails if only the `withOutput` guard is applied.
   - `CachedTableSuite`, an end-to-end test running the CTE self-join over a 
cached, ordered relation and checking the answer. Without either change it 
fails with `NoSuchElementException: key not found: k#...`. Note that this test 
covers the user-visible symptom, which either change fixes on its own.
   
   ```
   build/sbt "sql/testOnly 
org.apache.spark.sql.execution.columnar.InMemoryRelationSuite"
   build/sbt "sql/testOnly org.apache.spark.sql.CachedTableSuite"
   ```
   
   ### Was this patch authored or co-authored using generative AI tooling?
   
   Generated-by: Claude Code (model claude-opus-5)
   


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