Support STRING_ARRAY literal rendering

[xiangfu0]

Summary

• render STRING_ARRAY values in LiteralContext
• add unit coverage for Thrift STRING_ARRAY_VALUE conversion and rendering
• add an ArrayTest integration test that validates ingested multi-value STRING data and composed string-array literals in projections and ARRAYS_OVERLAP filters with both query engines

Reproduction

Before this change, a table-backed single-stage query such as:

SELECT intCol, stringArrayCol, ARRAY['query-a', 'query-b']
FROM ArrayTest
WHERE intCol = 0

folds the array constructor into a Thrift STRING_ARRAY_VALUE. When the server builds the selection result schema, LiteralContext.toString() throws:

IllegalStateException: Unsupported PinotDataType: STRING_ARRAY

Literal-only queries avoid the server selection path, which is why the failure requires a table-backed projection.

Validation

• LiteralContextTest: 11 tests passed
• ./mvnw -pl pinot-integration-tests -am -Dtest=ArrayTest#testFoldedStringArrayLiteralWithIngestedColumn -Dsurefire.failIfNoSpecifiedTests=false test: 2 tests passed, covering both query engines
• ./mvnw spotless:apply -pl pinot-common,pinot-integration-tests
• ./mvnw checkstyle:check -pl pinot-common,pinot-integration-tests
• ./mvnw license:format -pl pinot-common,pinot-integration-tests
• ./mvnw license:check -pl pinot-common,pinot-integration-tests

[Copilot]

Pull request overview

This PR fixes server-side rendering of folded STRING_ARRAY literals by teaching LiteralContext.toString() how to format PinotDataType.STRING_ARRAY, and adds unit + integration coverage to prevent regressions across both query engines.

Changes:

• Add STRING_ARRAY rendering support in LiteralContext.toString().
• Add unit test coverage for Thrift STRING_ARRAY_VALUE conversion + rendering behavior.
• Add an integration test that validates multi-value STRING ingestion and folded string-array literal behavior (projection + ARRAYS_OVERLAP) under both query engines.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
pinot-common/src/main/java/org/apache/pinot/common/request/context/LiteralContext.java	Adds STRING_ARRAY handling to toString() to avoid IllegalStateException during result rendering.
pinot-common/src/test/java/org/apache/pinot/common/request/context/LiteralContextTest.java	Adds a focused unit test validating STRING_ARRAY_VALUE conversion and toString() output.
pinot-integration-tests/src/test/java/org/apache/pinot/integration/tests/custom/ArrayTest.java	Adds an integration test covering ingested MV STRING column behavior plus folded string-array literals and ARRAYS_OVERLAP filtering across engines.

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[Jackie-Jiang]

How about MV BYTES? If needed, make a separate PR for it

[xiangfu0]

How about MV BYTES? If needed, make a separate PR for it

#19247