haohuaijin commented on code in PR #25568:
URL: https://github.com/apache/datafusion/pull/25568#discussion_r4063387256
##########
datafusion/sqllogictest/test_files/order.slt:
##########
@@ -1966,11 +1966,13 @@ EXPLAIN SELECT * from ordered ORDER BY (a + b);
----
physical_plan DataSourceExec: file_groups={1 group:
[[WORKSPACE_ROOT/datafusion/sqllogictest/data/composite_order.csv]]},
projection=[a, b], output_ordering=[a@0 + b@1 ASC NULLS LAST], file_type=csv,
has_header=true
-# Order equivalence handling should make this query a simple table scan
+# Negation may wrap at BIGINT's minimum, so the declared ordering is
insufficient.
query TT
EXPLAIN SELECT * from ordered ORDER BY -(a + b) desc nulls last;
----
-physical_plan DataSourceExec: file_groups={1 group:
[[WORKSPACE_ROOT/datafusion/sqllogictest/data/composite_order.csv]]},
projection=[a, b], output_ordering=[a@0 + b@1 ASC NULLS LAST], file_type=csv,
has_header=true
+physical_plan
+01)SortExec: expr=[(- a@0 + b@1) DESC NULLS LAST],
preserve_partitioning=[false]
+02)--DataSourceExec: file_groups={1 group:
[[WORKSPACE_ROOT/datafusion/sqllogictest/data/composite_order.csv]]},
projection=[a, b], output_ordering=[a@0 + b@1 ASC NULLS LAST], file_type=csv,
has_header=true
Review Comment:
As a follow-up to #25220, exact column statistics could prove that `a + b`
cannot reach `INT_MIN`, allowing us to safely reverse the declared ordering and
eliminate this SortExec.
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