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[SPARK-35080][SQL] Only allow a subset of correlated equality predica…
…tes when a subquery is aggregated ### What changes were proposed in this pull request? This PR updated the `foundNonEqualCorrelatedPred` logic for correlated subqueries in `CheckAnalysis` to only allow correlated equality predicates that guarantee one-to-one mapping between inner and outer attributes, instead of all equality predicates. ### Why are the changes needed? To fix correctness bugs. Before this fix Spark can give wrong results for certain correlated subqueries that pass CheckAnalysis: Example 1: ```sql create or replace view t1(c) as values ('a'), ('b') create or replace view t2(c) as values ('ab'), ('abc'), ('bc') select c, (select count(*) from t2 where t1.c = substring(t2.c, 1, 1)) from t1 ``` Correct results: [(a, 2), (b, 1)] Spark results: ``` +---+-----------------+ |c |scalarsubquery(c)| +---+-----------------+ |a |1 | |a |1 | |b |1 | +---+-----------------+ ``` Example 2: ```sql create or replace view t1(a, b) as values (0, 6), (1, 5), (2, 4), (3, 3); create or replace view t2(c) as values (6); select c, (select count(*) from t1 where a + b = c) from t2; ``` Correct results: [(6, 4)] Spark results: ``` +---+-----------------+ |c |scalarsubquery(c)| +---+-----------------+ |6 |1 | |6 |1 | |6 |1 | |6 |1 | +---+-----------------+ ``` ### Does this PR introduce _any_ user-facing change? Yes. Users will not be able to run queries that contain unsupported correlated equality predicates. ### How was this patch tested? Added unit tests. Closes apache#32179 from allisonwang-db/spark-35080-subquery-bug. Lead-authored-by: allisonwang-db <66282705+allisonwang-db@users.noreply.github.com> Co-authored-by: Wenchen Fan <cloud0fan@gmail.com> Signed-off-by: Wenchen Fan <wenchen@databricks.com>
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