[GH-3075] Add geography support to SedonaFlink spatial predicates

[jiayuasu]

Did you read the Contributor Guide?

• Yes, I have read the Contributor Rules and Contributor Development Guide

Is this PR related to a ticket?

• Yes, and the PR name follows the format [GH-XXX] my subject. Closes SedonaFlink: add geography support to spatial predicates #3075.

What changes were proposed in this PR?

Part of the geography parity effort for SedonaFlink (#3054), building on the type serializer (#3058), constructors (#3061), and functions (#3073).

This adds Geography support to the SedonaFlink spatial predicates, so geography columns can be compared, not just constructed and measured. Each of the following gains a Geography eval overload in flink/.../expressions/Predicates.java, delegating to org.apache.sedona.common.geography.Functions:

• ST_Intersects (geog, geog)
• ST_Contains (geog, geog)
• ST_Within (geog, geog)
• ST_Equals (geog, geog)
• ST_DWithin (geog, geog, distanceMeters)

Each overload uses @DataTypeHint(value = "RAW", rawSerializer = GeographyTypeSerializer.class, bridgedTo = Geography.class) and propagates SQL NULL the same way the existing geometry overloads do. Flink resolves geometry vs geography by the RAW bridgedTo type, so a single registered name serves both types and no new Catalog entries are required.

This mirrors Spark, where these predicates accept either Geometry or Geography.

Note on semantics: geography polygons follow the spherical right-hand rule — a CCW ring's interior is the enclosed region; a CW ring denotes the complementary region on the sphere. This is inherited from the common S2 layer and matches Spark.

How was this patch tested?

Added GeographyPredicateTest (6 tests) exercising each predicate end-to-end through the Flink Table API (true and false cases for ST_Intersects/ST_Equals/ST_DWithin), plus testGeometryStillWorks confirming the geometry overload still resolves on the shared predicate. No regressions: the geometry PredicateTest (22 tests) and ModuleTest pass.

Did this PR include necessary documentation updates?

• No. The SedonaFlink geography API docs (covering constructors, functions, and predicates together) are tracked as a separate sub-task of Add Geography type support to SedonaFlink (parity with Spark) #3054.

[Copilot]

Pull request overview

Adds Geography parity for SedonaFlink spatial predicates by introducing Geography-typed overloads for key predicate UDFs and validating behavior end-to-end via new Flink Table API tests.

Changes:

• Added Geography overloads for ST_Intersects, ST_Contains, ST_Within, ST_Equals, and ST_DWithin in Predicates.java, delegating to org.apache.sedona.common.geography.Functions.
• Introduced GeographyPredicateTest to exercise the new overloads through the Flink Table API and confirm geometry overload resolution still works.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
flink/src/main/java/org/apache/sedona/flink/expressions/Predicates.java	Adds Geography overloads for core spatial predicates using RAW type hints and GeographyTypeSerializer.
flink/src/test/java/org/apache/sedona/flink/GeographyPredicateTest.java	Adds end-to-end predicate tests for Geography and verifies geometry overload selection remains intact.

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[jiayuasu]

Added the NULL guard to ST_Within geometry overload (if (o1 == null || o2 == null) return null;), matching ST_Intersects/ST_Contains/ST_DWithin and the new geography overloads. Commit 0ffb38e.

[jiayuasu]

Added the same NULL guard to ST_Equals geometry overload for consistent NULL propagation across the predicate family. Commit 0ffb38e.