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https://issues.apache.org/jira/browse/DRILL-3912?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14964342#comment-14964342
]
ASF GitHub Bot commented on DRILL-3912:
---------------------------------------
Github user StevenMPhillips commented on a diff in the pull request:
https://github.com/apache/drill/pull/189#discussion_r42445808
--- Diff:
exec/java-exec/src/main/java/org/apache/drill/exec/expr/EqualityVisitor.java ---
@@ -0,0 +1,322 @@
+/**
+ * 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
+ * <p/>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p/>
+ * 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.expr;
+
+import com.google.common.collect.Lists;
+import org.apache.drill.common.expression.BooleanOperator;
+import org.apache.drill.common.expression.CastExpression;
+import org.apache.drill.common.expression.ConvertExpression;
+import org.apache.drill.common.expression.FunctionCall;
+import org.apache.drill.common.expression.FunctionHolderExpression;
+import org.apache.drill.common.expression.IfExpression;
+import org.apache.drill.common.expression.LogicalExpression;
+import org.apache.drill.common.expression.NullExpression;
+import org.apache.drill.common.expression.SchemaPath;
+import org.apache.drill.common.expression.TypedNullConstant;
+import
org.apache.drill.common.expression.ValueExpressions.BooleanExpression;
+import org.apache.drill.common.expression.ValueExpressions.DateExpression;
+import
org.apache.drill.common.expression.ValueExpressions.Decimal18Expression;
+import
org.apache.drill.common.expression.ValueExpressions.Decimal28Expression;
+import
org.apache.drill.common.expression.ValueExpressions.Decimal38Expression;
+import
org.apache.drill.common.expression.ValueExpressions.Decimal9Expression;
+import
org.apache.drill.common.expression.ValueExpressions.DoubleExpression;
+import org.apache.drill.common.expression.ValueExpressions.FloatExpression;
+import org.apache.drill.common.expression.ValueExpressions.IntExpression;
+import
org.apache.drill.common.expression.ValueExpressions.IntervalDayExpression;
+import
org.apache.drill.common.expression.ValueExpressions.IntervalYearExpression;
+import org.apache.drill.common.expression.ValueExpressions.LongExpression;
+import org.apache.drill.common.expression.ValueExpressions.QuotedString;
+import org.apache.drill.common.expression.ValueExpressions.TimeExpression;
+import
org.apache.drill.common.expression.ValueExpressions.TimeStampExpression;
+import org.apache.drill.common.expression.visitors.AbstractExprVisitor;
+
+import java.util.List;
+
+public class EqualityVisitor extends
AbstractExprVisitor<Boolean,LogicalExpression,RuntimeException> {
+ @Override
+ public Boolean visitFunctionCall(FunctionCall call, LogicalExpression
value) throws RuntimeException {
+ if (!(value instanceof FunctionCall)) {
+ return false;
+ }
+ if (!checkType(call, value)) {
+ return false;
+ }
+ if (!call.getName().equals(((FunctionCall) value).getName())) {
+ return false;
+ }
+ return checkChildren(call, value);
+ }
+
+ @Override
+ public Boolean visitFunctionHolderExpression(FunctionHolderExpression
holder, LogicalExpression value) throws RuntimeException {
+ if (!(value instanceof FunctionHolderExpression)) {
+ return false;
+ }
+ if (!checkType(holder, value)) {
+ return false;
+ }
+ if (!holder.getName().equals(((FunctionHolderExpression)
value).getName())) {
+ return false;
+ }
+ return checkChildren(holder, value);
+ }
+
+ @Override
+ public Boolean visitIfExpression(IfExpression ifExpr, LogicalExpression
value) throws RuntimeException {
+ if (!(value instanceof IfExpression)) {
+ return false;
+ }
+ return checkChildren(ifExpr, value);
+ }
+
+ @Override
+ public Boolean visitBooleanOperator(BooleanOperator call,
LogicalExpression value) throws RuntimeException {
+ if (!(value instanceof BooleanOperator)) {
+ return false;
+ }
+ if (!call.getName().equals(((BooleanOperator) value).getName())) {
+ return false;
+ }
+ return checkChildren(call, value);
+ }
+
+ @Override
+ public Boolean visitSchemaPath(SchemaPath path, LogicalExpression value)
throws RuntimeException {
+ if (!(value instanceof SchemaPath)) {
+ return false;
+ }
+ return path.equals(value);
+ }
+
+ @Override
+ public Boolean visitIntConstant(IntExpression intExpr, LogicalExpression
value) throws RuntimeException {
+ if (!(value instanceof IntExpression)) {
+ return false;
+ }
+ return intExpr.getInt() == ((IntExpression) value).getInt();
+ }
+
+ @Override
+ public Boolean visitFloatConstant(FloatExpression fExpr,
LogicalExpression value) throws RuntimeException {
+ if (!(value instanceof FloatExpression)) {
+ return false;
+ }
+ return fExpr.getFloat() == ((FloatExpression) value).getFloat();
+ }
+
+ @Override
+ public Boolean visitLongConstant(LongExpression intExpr,
LogicalExpression value) throws RuntimeException {
+ if (!(value instanceof LongExpression)) {
+ return false;
+ }
+ return intExpr.getLong() == ((LongExpression) value).getLong();
+ }
+
+ @Override
+ public Boolean visitDateConstant(DateExpression intExpr,
LogicalExpression value) throws RuntimeException {
+ if (!(value instanceof DateExpression)) {
+ return false;
+ }
+ return intExpr.getDate() == ((DateExpression) value).getDate();
+ }
+
+ @Override
+ public Boolean visitTimeConstant(TimeExpression intExpr,
LogicalExpression value) throws RuntimeException {
+ if (!(value instanceof TimeExpression)) {
+ return false;
+ }
+ return intExpr.getTime() == ((TimeExpression) value).getTime();
+ }
+
+ @Override
+ public Boolean visitTimeStampConstant(TimeStampExpression intExpr,
LogicalExpression value) throws RuntimeException {
+ if (!(value instanceof TimeStampExpression)) {
+ return false;
+ }
+ return intExpr.getTimeStamp() == ((TimeStampExpression)
value).getTimeStamp();
+ }
+
+ @Override
+ public Boolean visitIntervalYearConstant(IntervalYearExpression intExpr,
LogicalExpression value) throws RuntimeException {
+ if (!(value instanceof IntervalYearExpression)) {
+ return false;
+ }
+ return intExpr.getIntervalYear() == ((IntervalYearExpression)
value).getIntervalYear();
+ }
+
+ @Override
+ public Boolean visitIntervalDayConstant(IntervalDayExpression intExpr,
LogicalExpression value) throws RuntimeException {
+ if (!(value instanceof IntervalDayExpression)) {
+ return false;
+ }
+ return intExpr.getIntervalDay() == ((IntervalDayExpression)
value).getIntervalDay();
+ }
+
+ @Override
+ public Boolean visitDecimal9Constant(Decimal9Expression decExpr,
LogicalExpression value) throws RuntimeException {
+ if (!(value instanceof Decimal9Expression)) {
+ return false;
+ }
+ if (decExpr.getIntFromDecimal() != ((Decimal9Expression)
value).getIntFromDecimal()) {
+ return false;
+ }
+ if (decExpr.getScale() != ((Decimal9Expression) value).getScale()) {
+ return false;
+ }
+ if (decExpr.getPrecision() != ((Decimal9Expression)
value).getPrecision()) {
+ return false;
+ }
+ return true;
+ }
+
+ @Override
+ public Boolean visitDecimal18Constant(Decimal18Expression decExpr,
LogicalExpression value) throws RuntimeException {
+ if (!(value instanceof Decimal18Expression)) {
+ return false;
+ }
+ if (decExpr.getLongFromDecimal() != ((Decimal18Expression)
value).getLongFromDecimal()) {
+ return false;
+ }
+ if (decExpr.getScale() != ((Decimal18Expression) value).getScale()) {
+ return false;
+ }
+ if (decExpr.getPrecision() != ((Decimal18Expression)
value).getPrecision()) {
+ return false;
+ }
+ return true;
+ }
+
+ @Override
+ public Boolean visitDecimal28Constant(Decimal28Expression decExpr,
LogicalExpression value) throws RuntimeException {
+ if (!(value instanceof Decimal28Expression)) {
+ return false;
+ }
+ if (decExpr.getBigDecimal() != ((Decimal28Expression)
value).getBigDecimal()) {
+ return false;
+ }
+ return true;
+ }
+
+ @Override
+ public Boolean visitDecimal38Constant(Decimal38Expression decExpr,
LogicalExpression value) throws RuntimeException {
+ if (!(value instanceof Decimal38Expression)) {
+ return false;
+ }
+ if (decExpr.getBigDecimal() != ((Decimal38Expression)
value).getBigDecimal()) {
+ return false;
+ }
+ if (!decExpr.getMajorType().equals(((Decimal38Expression)
value).getMajorType())) {
+ return false;
+ }
+ return false;
+ }
+
+ @Override
+ public Boolean visitDoubleConstant(DoubleExpression dExpr,
LogicalExpression value) throws RuntimeException {
+ if (!(value instanceof DoubleExpression)) {
+ return false;
+ }
+ return dExpr.getDouble() == ((DoubleExpression) value).getDouble();
+ }
+
+ @Override
+ public Boolean visitBooleanConstant(BooleanExpression e,
LogicalExpression value) throws RuntimeException {
+ if (!(value instanceof BooleanExpression)) {
+ return false;
+ }
+ return e.getBoolean() == ((BooleanExpression) value).getBoolean();
+ }
+
+ @Override
+ public Boolean visitQuotedStringConstant(QuotedString e,
LogicalExpression value) throws RuntimeException {
+ if (!(value instanceof QuotedString)) {
+ return false;
+ }
+ return e.getString().equals(((QuotedString) value).getString());
+ }
+
+ @Override
+ public Boolean visitNullExpression(NullExpression e, LogicalExpression
value) throws RuntimeException {
+ if (!(value instanceof NullExpression)) {
+ return false;
+ }
+ return e.getMajorType().equals(value.getMajorType());
+ }
+
+ @Override
+ public Boolean visitCastExpression(CastExpression e, LogicalExpression
value) throws RuntimeException {
+ if (!(value instanceof CastExpression)) {
+ return false;
+ }
+ if (!e.getMajorType().equals(value.getMajorType())) {
+ return false;
+ }
+ return checkChildren(e, value);
+ }
+
+ @Override
+ public Boolean visitConvertExpression(ConvertExpression e,
LogicalExpression value) throws RuntimeException {
+ if (!(value instanceof ConvertExpression)) {
+ return false;
+ }
+ if (!e.getConvertFunction().equals(((ConvertExpression)
value).getConvertFunction())) {
+ return false;
+ }
+ return checkChildren(e, value);
+ }
+
+ @Override
+ public Boolean visitNullConstant(TypedNullConstant e, LogicalExpression
value) throws RuntimeException {
+ if (!(value instanceof TypedNullConstant)) {
+ return false;
+ }
+ return e.getMajorType().equals(e.getMajorType());
+ }
+
+ @Override
+ public Boolean visitUnknown(LogicalExpression e, LogicalExpression
value) throws RuntimeException {
+ if (e instanceof ValueVectorReadExpression && value instanceof
ValueVectorReadExpression) {
+ return visitValueVectorReadExpression((ValueVectorReadExpression) e,
(ValueVectorReadExpression) value);
+ }
+ return false;
+ }
+
+ private Boolean visitValueVectorReadExpression(ValueVectorReadExpression
e, ValueVectorReadExpression value) {
+ return e.getTypedFieldId().equals(value.getTypedFieldId());
--- End diff --
As I mention in my comment below, the cache is cleared whenever the
MappingSet is changed. I believe the incoming batch that is referred to here is
unique for a given mapping set. So I don't think this is a problem.
> Common subexpression elimination in code generation
> ---------------------------------------------------
>
> Key: DRILL-3912
> URL: https://issues.apache.org/jira/browse/DRILL-3912
> Project: Apache Drill
> Issue Type: Bug
> Reporter: Steven Phillips
> Assignee: Jinfeng Ni
>
> Drill currently will evaluate the full expression tree, even if there are
> redundant subtrees. Many of these redundant evaluations can be eliminated by
> reusing the results from previously evaluated expression trees.
> For example,
> {code}
> select a + 1, (a + 1)* (a - 1) from t
> {code}
> Will compute the entire (a + 1) expression twice. With CSE, it will only be
> evaluated once.
> The benefit will be reducing the work done when evaluating expressions, as
> well as reducing the amount of code that is generated, which could also lead
> to better JIT optimization.
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