Backport Parquet encoding tests for Spark 3.5

[eric-maynard]

This is a backport of c3d50e1, e667670, and 5d5e0a3, where tests were added for Spark 4.0 but not Spark 3.5.

[kevinjqliu]

Thanks for the PR!

For context, we're trying to make sure spark 3.5 and 4.0 have feature parity in the 1.10 release since this is the first release with Spark 4.0. More context in https://lists.apache.org/thread/8xzbg1wqft2grv8v1f13vb86vd8f7rjd

#13450 (comment)
#13391 (comment)

[huaxingao]

@eric-maynard Thanks for the back-port PR! Should we put these golden files in a common place so we don't have to add them for each Spark version?

[huaxingao]

@RussellSpitzer @stevenzwu @nastra @kevinjqliu
We originally planned to support the delta encodings only in Spark 4.0. Since we’re backporting support to Spark 3.5, we should place the golden files in a common location to avoid duplicating them across Spark versions. I’m thinking we can add these golden files under iceberg-parquet/src/test/parquet. Any thoughts?

[stevenzwu]

How about iceberg-parquet/src/test/resources?

[stevenzwu]

I removed this one from the 1.10.0 milestone as it is just test as @kevinjqliu says

[eric-maynard]

This is actually not just a test — the actual reader is being backported too.

…

On Thu, Aug 28, 2025 at 7:02 PM Steven Zhen Wu ***@***.***> wrote: *stevenzwu* left a comment (apache/iceberg#13859) <#13859 (comment)> I removed this one from the 1.10.0 milestone as it is just test as @kevinjqliu <https://github.com/kevinjqliu> says — Reply to this email directly, view it on GitHub <#13859 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AFRE3SF6TYD2F7LXPUHAVAT3P6YFBAVCNFSM6AAAAACEFZU5WCVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTEMZVGQ3DGOBSG4> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[kevinjqliu]

@eric-maynard from the 3 commits listed in the description (c3d50e1, e667670, and 5d5e0a3), i see only test files in the spark/v4.0 folder

do you know where i can find the reader being backported?

[eric-maynard]

Hey @kevinjqliu, my mistake, this is really only porting the tests. So you're right that it should not be a blocker.

[stevenzwu]

LGTM. just a nit comment

[stevenzwu]

Thanks @eric-maynard for the contribution, @nastra @huaxingao @kevinjqliu for the review