test(integ-test): stabilize floating window SUM cases

[mengweieric]

Description

Two SQL correctness cases were unstable when the flights fixture used multiple shards:

• SUM(DistanceMiles) OVER () intermittently differed from H2 and SQLite by 0.01.
• SUM(DistanceMiles) OVER (ORDER BY FlightDelayMin) also compared rows positionally even though 17 rows share the same ordering key and the query had no outer ORDER BY.

The correctness runner rounds floating cells to two decimals with CEILING and then compares them exactly. The legacy SQL engine preserves SUM(FLOAT) as FLOAT, so shard-dependent input order can move the single-precision result across a cent boundary without changing the window semantics.

This change casts only the summed operand in these two queries to DOUBLE. It also adds a unique outer ordering to the ordered case. The internal window order and its default RANGE frame remain unchanged.

No production code, shared comparator, or fixture is modified.

Validation

Focused tests used the official SQL correctness comparison framework against OpenSearch, H2, and SQLite.

Fixture shards	Repeated runs	Result
1	1	Pass
3	5	5/5 pass
5	10	10/10 pass

Mutation checks:

• Removing only the DOUBLE casts reproduced floating SUM failures in 10/10 five-shard runs.
• Removing only the outer tiebreaker reproduced positional failures in 3/3 five-shard runs.

compileTestJava and git diff --check pass.

Related Issues

None. This is a test-only alignment with the existing approximate floating-point contract.

Check List

• New functionality includes testing.
• Commits are signed per the DCO using --signoff or -s.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

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(Review updated until commit e13e060)

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PR Code Suggestions ✨

Latest suggestions up to e13e060
Explore these optional code suggestions:

Category	Suggestion	Impact
General	Add missing column to SELECT The ORDER BY clause references FlightNum which is not in the SELECT list. This may cause errors in some SQL engines or produce unexpected results. Consider either adding FlightNum to the SELECT clause or removing it from ORDER BY if it's not necessary for test stability. integ-test/src/test/resources/correctness/queries/window.txt [16] -SELECT FlightDelayMin, DistanceMiles, SUM(CAST(DistanceMiles AS DOUBLE)) OVER (ORDER BY FlightDelayMin) AS num FROM opensearch_dashboards_sample_data_flights ORDER BY FlightDelayMin, DistanceMiles, FlightNum +SELECT FlightDelayMin, DistanceMiles, FlightNum, SUM(CAST(DistanceMiles AS DOUBLE)) OVER (ORDER BY FlightDelayMin) AS num FROM opensearch_dashboards_sample_data_flights ORDER BY FlightDelayMin, DistanceMiles, FlightNum Suggestion importance[1-10]: 7 __ Why: The suggestion correctly identifies that FlightNum is referenced in the ORDER BY clause but not in the SELECT list. While some SQL engines allow this, adding it to SELECT ensures consistency and prevents potential errors across different SQL implementations.	Medium

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Previous suggestions

Suggestions up to commit 83fae4d

Category	Suggestion	Impact
Possible issue	Remove undefined column from ORDER BY The ORDER BY clause references FlightNum which is not in the SELECT list. This may cause errors in some SQL engines or produce unexpected results. Consider either adding FlightNum to the SELECT clause or removing it from the ORDER BY clause. integ-test/src/test/resources/correctness/queries/window.txt [16] -SELECT FlightDelayMin, DistanceMiles, SUM(CAST(DistanceMiles AS DOUBLE)) OVER (ORDER BY FlightDelayMin) AS num FROM opensearch_dashboards_sample_data_flights ORDER BY FlightDelayMin, DistanceMiles, FlightNum +SELECT FlightDelayMin, DistanceMiles, SUM(CAST(DistanceMiles AS DOUBLE)) OVER (ORDER BY FlightDelayMin) AS num FROM opensearch_dashboards_sample_data_flights ORDER BY FlightDelayMin, DistanceMiles Suggestion importance[1-10]: 7 __ Why: The suggestion correctly identifies that FlightNum is referenced in the ORDER BY clause but not in the SELECT list. While some SQL engines allow this, it can cause issues or unexpected behavior. However, this may be intentional for testing purposes in an integration test file.	Medium

[dai-chen]

I forgot where is exact the code. But could you double check if adjust precision is the better way like here https://github.com/opensearch-project/sql/blob/main/integ-test/src/test/java/org/opensearch/sql/correctness/runner/resultset/Row.java#L37

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Persistent review updated to latest commit e13e060