No need to use Coalesce in InnerJoin

trinodb · Dec 20, 2024 · 1e872ea · 1e872ea
1 parent 92c1fdd
commit 1e872ea
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Showing 2 changed files with 9 additions and 5 deletions.
diff --git a/core/trino-main/src/main/java/io/trino/sql/planner/QueryPlanner.java b/core/trino-main/src/main/java/io/trino/sql/planner/QueryPlanner.java
@@ -450,8 +450,7 @@ public RelationPlan plan(QuerySpecification node)
 
             // The new scope is the composite of the fields from the FROM and SELECT clause (local nested scopes). Fields from the bottom of
             // the scope stack need to be placed first to match the expected layout for nested scopes.
-            List<Symbol> newFields = new ArrayList<>();
-            newFields.addAll(builder.getTranslations().getFieldSymbols());
+            List<Symbol> newFields = new ArrayList<>(builder.getTranslations().getFieldSymbols());
 
             outputs.stream()
                     .map(builder::translate)

diff --git a/core/trino-main/src/main/java/io/trino/sql/planner/RelationPlanner.java b/core/trino-main/src/main/java/io/trino/sql/planner/RelationPlanner.java
@@ -1179,9 +1179,14 @@ If casts are redundant (due to column type and common type being equal),
         for (Identifier column : joinColumns) {
             Symbol output = symbolAllocator.newSymbol(column.getValue(), analysis.getType(column));
             outputs.add(output);
-            assignments.put(output, new Coalesce(
-                    leftJoinColumns.get(column).toSymbolReference(),
-                    rightJoinColumns.get(column).toSymbolReference()));
+            if (join.getType() == JoinType.INNER) {
+                assignments.put(output, leftJoinColumns.get(column).toSymbolReference());
+            }
+            else {
+                assignments.put(output, new Coalesce(
+                        leftJoinColumns.get(column).toSymbolReference(),
+                        rightJoinColumns.get(column).toSymbolReference()));
+            }
         }
 
         for (int field : joinAnalysis.getOtherLeftFields()) {