Pre-size projection BlockBuilder to the exact size needed

trinodb · Oct 1, 2022 · ab83378 · ab83378
1 parent f84509e
commit ab83378
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/core/trino-main/src/main/java/io/trino/operator/project/GeneratedPageProjection.java b/core/trino-main/src/main/java/io/trino/operator/project/GeneratedPageProjection.java
@@ -67,7 +67,7 @@ public InputChannels getInputChannels()
     @Override
     public Work<Block> project(ConnectorSession session, DriverYieldSignal yieldSignal, Page page, SelectedPositions selectedPositions)
     {
-        blockBuilder = blockBuilder.newBlockBuilderLike(null);
+        blockBuilder = blockBuilder.newBlockBuilderLike(selectedPositions.size(), null);
         try {
             return (Work<Block>) pageProjectionWorkFactory.invoke(blockBuilder, session, page, selectedPositions);
         }