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Core, Spark: Fix equality deletes non-deterministic schema ordering (#13873) - #15514

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amogh-jahagirdar merged 4 commits into
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RussellSpitzer:FixEqualityCacheIssue
Mar 12, 2026
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amogh-jahagirdar merged 4 commits into
apache:mainfrom
RussellSpitzer:FixEqualityCacheIssue

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@RussellSpitzer

@RussellSpitzer RussellSpitzer commented Mar 4, 2026 •

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Equality delete schemas constructed in DeleteFilter.applyEqDeletes relied on the field order of requiredSchema, which varies depending on the query's projection. When the SparkExecutorCache returned delete records read with one field ordering to a reader expecting another, StructProjection silently misinterpreted the positional data, causing deletes to be skipped.

We fix this by Canonicalize the deleteSchema by sorting fields by field ID. Now every reader produces the same schema for deletes regardless of projection, ensuring cache hits return correctly ordered records.

Coded with the help of Cursor and claude-4.6.opus-high

--
TLDR;

First call read with schema [a,b] for deletes:
read+project(file, [a,b]) → cache_projected_deletes(file) → applyDeletes with [a,b]

Second call reads with Schema [b, a] for deletes:
load_cache_projected_deletes(file) → applyDeletes with [b,a] → mismatch

Fixes #13873

…hema ordering (apache#13873)

Equality delete schemas constructed in DeleteFilter.applyEqDeletes relied on
the field order of requiredSchema, which varies depending on the query's
projection. When the SparkExecutorCache returned delete records read with one
field ordering to a reader expecting another, StructProjection silently
misinterpreted the positional data, causing deletes to be skipped.

We fix this by Canonicalize the deleteSchema by sorting fields by field ID. Now
every reader produces the same schema for deletes regardless of projection,
ensuring cache hits return correctly ordered records.

Coded with the help of Cursor and claude-4.6.opus-high
Comment thread data/src/main/java/org/apache/iceberg/data/DeleteFilter.java

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LGTM. Looks like the cache key is the delete file itself, which makes sense, as long as we use a deterministic approach for the schema projection.

eqTestTable.newRowDelta().addDeletes(eqFile).commit();

String tableRef = TableIdentifier.of("default", EQ_CACHE_TABLE).toString();
int expectedRows = 7;

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nit: maybe a little bit easier to understand?

Suggested change
int expectedRows = 7;
int expectedRows = data.size() - delete.size();

Types.NestedField.optional(1, "id", Types.IntegerType.get()),
Types.NestedField.optional(2, "a", Types.IntegerType.get()),
Types.NestedField.optional(3, "b", Types.IntegerType.get()));
PartitionSpec spec = PartitionSpec.builderFor(eqDeleteTestSchema).bucket("id", 1).build();

@pvary pvary Mar 6, 2026 •

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Why do we not use an unpartitioned table here?

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No reason, I originally had this in a different file where all the tables were partitioned and I didn't want to feel left out. Now that it's here we can remove it

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Marked a few places where the code could made cleaner

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LGTM. thanks for adding the unit test. just a couple of nit comments

Comment thread data/src/main/java/org/apache/iceberg/data/DeleteFilter.java Outdated
* order than the table schema, which can cause different deleteSchema orderings, poisoning the
* cache.
*/
@TestTemplate

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The actual test makes sense, but I don't see why it is necessary to run this test of a core feature (DeleteFilter) in Spark. This should be done in the tests for that class.

@RussellSpitzer RussellSpitzer Mar 6, 2026 •

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Main reason is I couldn't find a place to fit it in any of those places. I did try but it basically involved writing a custom test cache implementation as well. So while it's possible it basically involves re-implementing everything to get the same behavior. We could add a unit test for sorting though, that's pretty easy

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Yeah it looks like we currently don't have a great place for testing out just the logic within DeleteFilter. I think in the current structure, we'd have to have our own implementation of DeleteFilter for the test and as @RussellSpitzer said by the time we do all that it's basically just re-implementing what we have in the engine integrations like Spark. I think I agree with the current split of tests, but maybe the fact that we want to test DeleteFilter in isolation means we need to do some refactoring.

@RussellSpitzer RussellSpitzer Mar 6, 2026 •

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https://gist.github.com/sfc-gh-rspitzer/e53841222262010847a68aa2ed59dd39 < Here is what Claude thinks that should look like. I haven't really gone through it in depth I just figured if I was writing an implementation of DeleteFilter and DeleteLoader we are going way off track.

Basically we mock just about everything around the load, just to test that the schema is always canonicalized.

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I didn't realize that the caching part was tied to Spark. This should be okay.

@rdblue rdblue added this to the Iceberg 1.11.0 milestone Mar 6, 2026
@rdblue

rdblue commented Mar 6, 2026

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@amogh-jahagirdar FYI. Here's another one for the next 1.10.x release.

@github-actions github-actions Bot added the API label Mar 6, 2026

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This looks right to me, thank you @RussellSpitzer !

* order than the table schema, which can cause different deleteSchema orderings, poisoning the
* cache.
*/
@TestTemplate

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Yeah it looks like we currently don't have a great place for testing out just the logic within DeleteFilter. I think in the current structure, we'd have to have our own implementation of DeleteFilter for the test and as @RussellSpitzer said by the time we do all that it's basically just re-implementing what we have in the engine integrations like Spark. I think I agree with the current split of tests, but maybe the fact that we want to test DeleteFilter in isolation means we need to do some refactoring.

Comment thread api/src/main/java/org/apache/iceberg/types/TypeUtil.java Outdated
@RussellSpitzer

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@rdblue Any final thoughts? Are you onboard with the test even though I agree it is quite suboptimal. We may just want to raise another issue to refactor this whole bit of code into something more testable ...

@amogh-jahagirdar

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I'll go ahead and merge, thanks @RussellSpitzer and all for reviewing!

@amogh-jahagirdar
amogh-jahagirdar merged commit f865bac into apache:main Mar 12, 2026
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amogh-jahagirdar pushed a commit that referenced this pull request Mar 12, 2026
… schema ordering

Equality delete schemas constructed in DeleteFilter.applyEqDeletes relied on
the field order of requiredSchema, which varies depending on the query's
projection. When the SparkExecutorCache returned delete records read with one
field ordering to a reader expecting another, StructProjection silently
misinterpreted the positional data, causing deletes to be skipped.

We fix this by Canonicalize the deleteSchema by sorting fields by field ID. Now
every reader produces the same schema for deletes regardless of projection,
ensuring cache hits return correctly ordered records.

Coded with the help of Cursor and claude-4.6.opus-high
@RussellSpitzer
RussellSpitzer deleted the FixEqualityCacheIssue branch April 23, 2026 14:38
wjxiz1992 added a commit to NVIDIA/cudf-spark that referenced this pull request Sep 15, 2026
…ed-it] [databricks] (#15964)

**JaCoCo production line coverage: not fully measurable locally — no
compatible Scala 2.13 / shim 411 nightly baseline is published.**

Contributes to #12885.

### Description

This test-only recovery restores enforced CPU/GPU result checks for
mixed Iceberg position and equality deletes on Iceberg 1.10.2 and newer.
Before this change, the format-v2 and format-v3 cases were permanent
expected failures with fixed data seeds even on runtimes containing the
upstream equality-delete cache fix. The affected older releases are now
skipped instead of spending test time on known failures; production
behavior is unchanged.

[Apache Iceberg #15514](apache/iceberg#15514),
released in 1.11.0 and [backported to
1.10.2](apache/iceberg#15605), fixes
equality-delete records being cached in a query-dependent field order.
This PR:

- Skips both mixed-delete tests on Iceberg versions older than 1.10.2,
removes their expected-failure markers and permanent seed overrides on
fixed versions, and fails pytest configuration when `--iceberg` lacks an
expected runtime version.
- Passes the expected Iceberg version through the Spark 4.0
extra-classpath pre-merge launcher and documents the required
environment variable.
- Keeps every count, full-row, and GPU-scan assertion. For the format-v3
count query only, disables adaptive query execution so plan validation
sees the completed scan, then resets session configuration before
fixture cleanup.

Older supported dependencies are not fixed by this PR, so #12885 should
remain open. Iceberg 1.10.2 was policy-checked but was not
GPU-runtime-tested locally. Shared pytest configuration and pre-merge
launcher paths changed, so Databricks remains in CI scope.

#### Validation

- Spark 4.1.1 / Iceberg 1.11.0 / Python 3.10: all six focused
format-v2/format-v3 CPU/GPU cases passed across the three reader modes
(`6 passed, 45 deselected` in 219.85 seconds). Full-row equality and the
format-v3 `GpuBatchScanExec` assertion were exercised.
- Spark 4.0.0 / Iceberg 1.10.1 / Python 3.10: all six focused cases were
selected and skipped (`6 skipped, 45 deselected` in 1.73 seconds).
- Seven release-boundary checks and two decorator-policy checks passed.
The checked cases cover missing version, 1.6.1, 1.9.2, 1.10.0, 1.10.1,
1.10.2, and 1.11.0.
- Unset `EXPECTED_ICEBERG_VERSION` with `--iceberg` failed during pytest
configuration with exit 4 and the expected error. `bash -n` and a
focused launcher probe confirmed that the Spark 4.0 extra-classpath path
forwards Iceberg 1.10.1.
- Python 3.10 compilation and `git diff --check` passed.

No production performance change is expected.

AI assistance: The change and PR description were prepared with Codex
assistance.

### Checklists

Documentation
- [ ] Updated for new or modified user-facing features or behaviors
- [x] No user-facing change

Testing
- [x] Added or modified tests to cover new code paths
- [ ] Covered by existing tests
(Please provide the names of the existing tests in the PR description.)
- [ ] Not required

Performance
- [ ] Tests ran and results are added in the PR description
- [ ] Issue filed with a link in the PR description
- [x] Not required

---------

Signed-off-by: Allen Xu <allxu@nvidia.com>
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Undetermined behavior when fetching from iceberg table

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