Github user chunhui-shi commented on a diff in the pull request:
https://github.com/apache/drill/pull/1104#discussion_r166088073
--- Diff:
exec/java-exec/src/main/java/org/apache/drill/exec/planner/logical/DrillFilterItemStarReWriterRule.java
---
@@ -0,0 +1,232 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.drill.exec.planner.logical;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
+import org.apache.calcite.adapter.enumerable.EnumerableTableScan;
+import org.apache.calcite.plan.RelOptRule;
+import org.apache.calcite.plan.RelOptRuleCall;
+import org.apache.calcite.plan.RelOptRuleOperand;
+import org.apache.calcite.plan.RelOptTable;
+import org.apache.calcite.prepare.RelOptTableImpl;
+import org.apache.calcite.rel.RelNode;
+import org.apache.calcite.rel.core.CorrelationId;
+import org.apache.calcite.rel.core.Filter;
+import org.apache.calcite.rel.core.Project;
+import org.apache.calcite.rel.core.TableScan;
+import org.apache.calcite.rel.logical.LogicalFilter;
+import org.apache.calcite.rel.logical.LogicalProject;
+import org.apache.calcite.rel.type.RelDataType;
+import org.apache.calcite.rel.type.RelDataTypeFactory;
+import org.apache.calcite.rel.type.RelDataTypeField;
+import org.apache.calcite.rex.RexCall;
+import org.apache.calcite.rex.RexInputRef;
+import org.apache.calcite.rex.RexNode;
+import org.apache.calcite.rex.RexVisitorImpl;
+import org.apache.calcite.schema.Table;
+import org.apache.drill.exec.planner.types.RelDataTypeDrillImpl;
+import org.apache.drill.exec.planner.types.RelDataTypeHolder;
+import org.apache.drill.exec.util.Utilities;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import static
org.apache.drill.exec.planner.logical.FieldsReWriterUtil.DesiredField;
+import static
org.apache.drill.exec.planner.logical.FieldsReWriterUtil.FieldsReWriter;
+
+/**
+ * Rule will transform filter -> project -> scan call with item star
fields in filter
+ * into project -> filter -> project -> scan where item star fields are
pushed into scan
+ * and replaced with actual field references.
+ *
+ * This will help partition pruning and push down rules to detect fields
that can be pruned or push downed.
+ * Item star operator appears when sub-select or cte with star are used as
source.
+ */
+public class DrillFilterItemStarReWriterRule extends RelOptRule {
+
+ public static final DrillFilterItemStarReWriterRule INSTANCE = new
DrillFilterItemStarReWriterRule(
+ RelOptHelper.some(Filter.class, RelOptHelper.some(Project.class,
RelOptHelper.any( TableScan.class))),
+ "DrillFilterItemStarReWriterRule");
+
+ private DrillFilterItemStarReWriterRule(RelOptRuleOperand operand,
String id) {
+ super(operand, id);
+ }
+
+ @Override
+ public void onMatch(RelOptRuleCall call) {
+ Filter filterRel = call.rel(0);
+ Project projectRel = call.rel(1);
+ TableScan scanRel = call.rel(2);
+
+ ItemStarFieldsVisitor itemStarFieldsVisitor = new
ItemStarFieldsVisitor(filterRel.getRowType().getFieldNames());
--- End diff --
To make sure this works for complex expressions, could you add tests
similar to testPushProjectIntoScan to test some expressions that include more
than two fields in expressions in project(e.g. "select a+b") and in filter(e.g.
"where a+b < 5")?
---
