xiedeyantu commented on code in PR #4515:
URL: https://github.com/apache/calcite/pull/4515#discussion_r2312523426
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core/src/main/java/org/apache/calcite/rel/rules/SortJoinTransposeRule.java:
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@@ -23,18 +23,23 @@
import org.apache.calcite.rel.RelFieldCollation;
import org.apache.calcite.rel.RelNode;
import org.apache.calcite.rel.core.Join;
-import org.apache.calcite.rel.core.JoinInfo;
import org.apache.calcite.rel.core.JoinRelType;
import org.apache.calcite.rel.core.Sort;
import org.apache.calcite.rel.logical.LogicalJoin;
import org.apache.calcite.rel.logical.LogicalSort;
import org.apache.calcite.rel.metadata.RelMdUtil;
import org.apache.calcite.rel.metadata.RelMetadataQuery;
+import org.apache.calcite.rex.RexBuilder;
import org.apache.calcite.rex.RexDynamicParam;
+import org.apache.calcite.rex.RexLiteral;
+import org.apache.calcite.rex.RexNode;
import org.apache.calcite.tools.RelBuilderFactory;
+import org.checkerframework.checker.nullness.qual.Nullable;
import org.immutables.value.Value;
+import java.math.BigDecimal;
+
Review Comment:
I'm not sure if this JavaDoc is appropriate, please take a look and if so,
I'll update it. Alternatively, I'd appreciate any suggestions.
```
/**
* Planner rule that pushes a {@link Sort} past a {@link Join} to enable
more efficient sorting.
*
* <p>This rule applies to left and right outer joins, and only pushes the
sort if its keys are entirely from one input.
* It will not fire if the sort uses dynamic parameters or the input is
already sorted and limited.
*
* <p>For example, given the SQL:
* <pre>
* SELECT * FROM EMP
* LEFT JOIN DEPT ON EMP.deptno = DEPT.deptno
* ORDER BY EMP.ename
* LIMIT 10
* </pre>
* The initial plan:
* <pre>
* LogicalSort(fetch=[10], sort0=[$1], dir0=[ASC])
* LogicalJoin(condition=[=($0, $2)], joinType=[left])
* LogicalTableScan(table=[[EMP]])
* LogicalTableScan(table=[[DEPT]])
* </pre>
* After applying this rule:
* <pre>
* LogicalSort(fetch=[10], sort0=[$1], dir0=[ASC])
* LogicalJoin(condition=[=($0, $2)], joinType=[left])
* LogicalSort(fetch=[10], sort0=[$1], dir0=[ASC])
* LogicalTableScan(table=[[EMP]])
* LogicalTableScan(table=[[DEPT]])
* </pre>
*
* @see org.apache.calcite.rel.rules.CoreRules#SORT_JOIN_TRANSPOSE
*/
```
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