Add and use Window.setEvaluatable()

h2/src/main/org/h2/expression/aggregate/AbstractAggregate.java

@@ -7,6 +7,7 @@ package org.h2.expression.aggregate;
 
 import org.h2.expression.Expression;
 import org.h2.table.ColumnResolver;
+import org.h2.table.TableFilter;
 
 /**
  * A base class for aggregates.
@@ -47,6 +48,16 @@ public abstract class AbstractAggregate extends Expression {
         }
     }
 
+    @Override
+    public void setEvaluatable(TableFilter tableFilter, boolean b) {
+        if (filterCondition != null) {
+            filterCondition.setEvaluatable(tableFilter, b);
+        }
+        if (over != null) {
+            over.setEvaluatable(tableFilter, b);
+        }
+    }
+
     protected StringBuilder appendTailConditions(StringBuilder builder) {
         if (filterCondition != null) {
             builder.append(" FILTER (WHERE ").append(filterCondition.getSQL()).append(')');

h2/src/main/org/h2/expression/aggregate/Aggregate.java

@@ -588,9 +588,7 @@ public class Aggregate extends AbstractAggregate {
         if (groupConcatSeparator != null) {
             groupConcatSeparator.setEvaluatable(tableFilter, b);
         }
-        if (filterCondition != null) {
-            filterCondition.setEvaluatable(tableFilter, b);
-        }
+        super.setEvaluatable(tableFilter, b);
     }
 
     @Override

h2/src/main/org/h2/expression/aggregate/JavaAggregate.java

@@ -149,9 +149,7 @@ public class JavaAggregate extends AbstractAggregate {
         for (Expression e : args) {
             e.setEvaluatable(tableFilter, b);
         }
-        if (filterCondition != null) {
-            filterCondition.setEvaluatable(tableFilter, b);
-        }
+        super.setEvaluatable(tableFilter, b);
     }
 
     private Aggregate getInstance() throws SQLException {

h2/src/main/org/h2/expression/aggregate/Window.java

@@ -10,6 +10,7 @@ import java.util.ArrayList;
 import org.h2.engine.Session;
 import org.h2.expression.Expression;
 import org.h2.table.ColumnResolver;
+import org.h2.table.TableFilter;
 import org.h2.util.StringUtils;
 import org.h2.value.Value;
 import org.h2.value.ValueArray;
@@ -47,6 +48,23 @@ public final class Window {
         }
     }
 
+    /**
+     * Tell the expression columns whether the table filter can return values
+     * now. This is used when optimizing the query.
+     *
+     * @param tableFilter
+     *            the table filter
+     * @param value
+     *            true if the table filter can return value
+     */
+    public void setEvaluatable(TableFilter tableFilter, boolean value) {
+        if (partitionBy != null) {
+            for (Expression e : partitionBy) {
+                e.setEvaluatable(tableFilter, value);
+            }
+        }
+    }
+
     /**
      * Returns the key for the current group.
      *