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/**
* 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.hadoop.hive.ql.optimizer.physical;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Stack;
import org.apache.hadoop.hive.ql.exec.ColumnInfo;
import org.apache.hadoop.hive.ql.exec.FileSinkOperator;
import org.apache.hadoop.hive.ql.exec.ForwardOperator;
import org.apache.hadoop.hive.ql.exec.GroupByOperator;
import org.apache.hadoop.hive.ql.exec.JoinOperator;
import org.apache.hadoop.hive.ql.exec.Operator;
import org.apache.hadoop.hive.ql.exec.ReduceSinkOperator;
import org.apache.hadoop.hive.ql.exec.SelectOperator;
import org.apache.hadoop.hive.ql.lib.Node;
import org.apache.hadoop.hive.ql.lib.NodeProcessor;
import org.apache.hadoop.hive.ql.lib.NodeProcessorCtx;
import org.apache.hadoop.hive.ql.lib.Utils;
import org.apache.hadoop.hive.ql.optimizer.physical.BucketingSortingCtx.BucketCol;
import org.apache.hadoop.hive.ql.optimizer.physical.BucketingSortingCtx.BucketSortCol;
import org.apache.hadoop.hive.ql.optimizer.physical.BucketingSortingCtx.SortCol;
import org.apache.hadoop.hive.ql.parse.SemanticException;
import org.apache.hadoop.hive.ql.plan.ExprNodeColumnDesc;
import org.apache.hadoop.hive.ql.plan.ExprNodeDesc;
import org.apache.hadoop.hive.ql.plan.ExprNodeDescUtils;
import org.apache.hadoop.hive.ql.plan.GroupByDesc;
import org.apache.hadoop.hive.ql.plan.JoinDesc;
import org.apache.hadoop.hive.ql.plan.OperatorDesc;
import org.apache.hadoop.hive.ql.plan.ReduceSinkDesc;
import org.apache.hadoop.hive.ql.plan.SelectDesc;
/**
* Operator factory for the rule processors for inferring bucketing/sorting columns.
*/
public class BucketingSortingOpProcFactory {
public static class DefaultInferrer implements NodeProcessor {
@Override
public Object process(Node nd, Stack stack, NodeProcessorCtx procCtx,
Object... nodeOutputs) throws SemanticException {
return null;
}
}
/**
* Infers bucket/sort columns for operators which simply forward rows from the parent
* E.g. Forward operators and SELECT *
* @param op
* @param bctx
* @param parent
* @throws SemanticException
*/
private static void processForward(Operator op, BucketingSortingCtx bctx,
Operator parent) throws SemanticException {
List bucketCols = bctx.getBucketedCols(parent);
List sortCols = bctx.getSortedCols(parent);
List colInfos = op.getSchema().getSignature();
if (bucketCols == null && sortCols == null) {
return;
}
List newBucketCols;
List newSortCols;
if (bucketCols == null) {
newBucketCols = null;
} else {
newBucketCols = getNewBucketCols(bucketCols, colInfos);
}
if (sortCols == null) {
newSortCols = null;
} else {
newSortCols = getNewSortCols(sortCols, colInfos);
}
bctx.setBucketedCols(op, newBucketCols);
bctx.setSortedCols(op, newSortCols);
}
/**
* Returns the parent operator in the walk path to the current operator.
*
* @param stack The stack encoding the path.
*
* @return Operator The parent operator in the current path.
*/
@SuppressWarnings("unchecked")
protected static Operator getParent(Stack stack) {
return (Operator)Utils.getNthAncestor(stack, 1);
}
/**
* Processor for Join Operator.
*
* This handles common joins, the tree should look like
* ReducSinkOperator
* \
* .... --- JoinOperator
* /
* ReduceSink Operator
*
*/
public static class JoinInferrer extends DefaultInferrer implements NodeProcessor {
@Override
public Object process(Node nd, Stack stack, NodeProcessorCtx procCtx,
Object... nodeOutputs) throws SemanticException {
BucketingSortingCtx bctx = (BucketingSortingCtx)procCtx;
JoinOperator jop = (JoinOperator)nd;
JoinDesc joinDesc = jop.getConf();
Byte[] order = joinDesc.getTagOrder();
Map> expressions = joinDesc.getExprs();
List outputValNames = joinDesc.getOutputColumnNames();
BucketCol[] newBucketCols = null;
SortCol[] newSortCols = null;
for (int i = 0; i < jop.getParentOperators().size(); i++) {
Operator parent = jop.getParentOperators().get(i);
// The caller of this method should guarantee this
assert(parent instanceof ReduceSinkOperator);
ReduceSinkOperator rop = (ReduceSinkOperator)jop.getParentOperators().get(i);
ReduceSinkDesc rsDesc = rop.getConf();
byte tag = (byte) rsDesc.getTag();
List joinValues = expressions.get(tag);
// Columns are output from the join from the different reduce sinks in the order of their
// offsets
int offset = 0;
for (byte orderIndex = 0; orderIndex < order.length; orderIndex++) {
if (order[orderIndex] < order[tag]) {
offset += expressions.get(orderIndex).size();
}
}
String sortOrder = rsDesc.getOrder();
List keyCols = rsDesc.getKeyCols();
List valCols = ExprNodeDescUtils.backtrack(joinValues, jop, parent);
if (newBucketCols == null) {
newBucketCols = new BucketCol[keyCols.size()];
newSortCols = new SortCol[keyCols.size()];
}
// Go through the Reduce keys and find the matching column(s) in the reduce values
for (int keyIndex = 0 ; keyIndex < keyCols.size(); keyIndex++) {
ExprNodeDesc key = keyCols.get(keyIndex);
int index = ExprNodeDescUtils.indexOf(key, valCols);
if (index >= 0) {
int vindex = offset + index;
String vname = outputValNames.get(vindex);
if (newBucketCols[keyIndex] != null) {
newBucketCols[keyIndex].addAlias(vname, vindex);
newSortCols[keyIndex].addAlias(vname, vindex);
} else {
newBucketCols[keyIndex] = new BucketCol(vname, vindex);
newSortCols[keyIndex] = new SortCol(vname, vindex, sortOrder.charAt(keyIndex));
}
}
}
}
List bucketCols = Arrays.asList(newBucketCols);
if (!bucketCols.contains(null)) {
bctx.setBucketedCols(jop, bucketCols);
}
List sortCols = Arrays.asList(newSortCols);
if (!sortCols.contains(null)) {
bctx.setSortedCols(jop, sortCols);
}
return null;
}
}
/**
* If the list of output bucket columns has been populated and every column has at least
* one representative in the output they can be inferred
*
* @param bctx - BucketingSortingCtx containing inferred columns
* @param op - The operator we are inferring information about the output of
* @param newBucketCols - An array of columns on which the output is bucketed, e.g. as output by
* the method findBucketingSortingColumns
*/
private static void setBucketingColsIfComplete(BucketingSortingCtx bctx,
Operator op, BucketCol[] newBucketCols) {
if (newBucketCols != null) {
List newBucketColList = Arrays.asList(newBucketCols);
// If newBucketColList had a null value it means that at least one of the input bucket
// columns did not have a representative found in the output columns, so assume the data
// is no longer bucketed
if (!newBucketColList.contains(null)) {
bctx.setBucketedCols(op, newBucketColList);
}
}
}
/**
* If the list of output sort columns has been populated and every column has at least
* one representative in the output they can be inferred
*
* @param bctx - BucketingSortingCtx containing inferred columns
* @param op - The operator we are inferring information about the output of
* @param newSortCols - An array of columns on which the output is sorted, e.g. as output by
* the method findBucketingSortingColumns
*/
private static void setSortingColsIfComplete(BucketingSortingCtx bctx,
Operator op, SortCol[] newSortCols) {
if (newSortCols != null) {
List newSortColList = Arrays.asList(newSortCols);
// If newSortColList had a null value it means that at least one of the input sort
// columns did not have a representative found in the output columns, so assume the data
// is no longer sorted
if (!newSortColList.contains(null)) {
bctx.setSortedCols(op, newSortColList);
}
}
}
private static void findBucketingSortingColumns(List exprs,
List colInfos, List bucketCols, List sortCols,
BucketCol[] newBucketCols, SortCol[] newSortCols) {
findBucketingSortingColumns(exprs, colInfos, bucketCols, sortCols, newBucketCols,
newSortCols, 0);
}
/**
* For each expression, check if it represents a column known to be bucketed/sorted.
*
* The methods setBucketingColsIfComplete and setSortingColsIfComplete should be used to assign
* the values of newBucketCols and newSortCols as the bucketing/sorting columns of this operator
* because these arrays may contain nulls indicating that the output of this operator is not
* bucketed/sorted.
*
* @param exprs - list of expression
* @param colInfos - list of column infos
* @param bucketCols - list of bucketed columns from the input
* @param sortCols - list of sorted columns from the input
* @param newBucketCols - an array of bucket columns which should be the same length as
* bucketCols, updated such that the bucketed column(s) at index i in bucketCols became
* the bucketed column(s) at index i of newBucketCols in the output
* @param newSortCols - an array of sort columns which should be the same length as
* sortCols, updated such that the sorted column(s) at index i in sortCols became
* the sorted column(s) at index i of sortCols in the output
* @param colInfosOffset - the expressions are known to be represented by column infos
* beginning at this index
*/
private static void findBucketingSortingColumns(List exprs,
List colInfos, List bucketCols, List sortCols,
BucketCol[] newBucketCols, SortCol[] newSortCols, int colInfosOffset) {
for(int cnt = 0; cnt < exprs.size(); cnt++) {
ExprNodeDesc expr = exprs.get(cnt);
// Only columns can be sorted/bucketed, in particular applying a function to a column
// voids any assumptions
if (!(expr instanceof ExprNodeColumnDesc)) {
continue;
}
ExprNodeColumnDesc columnExpr = (ExprNodeColumnDesc)expr;
int colInfosIndex = cnt + colInfosOffset;
if (newBucketCols != null) {
int bucketIndex = indexOfColName(bucketCols, columnExpr.getColumn());
if (bucketIndex != -1) {
if (newBucketCols[bucketIndex] == null) {
newBucketCols[bucketIndex] = new BucketCol();
}
newBucketCols[bucketIndex].addAlias(
colInfos.get(colInfosIndex).getInternalName(), colInfosIndex);
}
}
if (newSortCols != null) {
int sortIndex = indexOfColName(sortCols, columnExpr.getColumn());
if (sortIndex != -1) {
if (newSortCols[sortIndex] == null) {
newSortCols[sortIndex] = new SortCol(sortCols.get(sortIndex).getSortOrder());
}
newSortCols[sortIndex].addAlias(
colInfos.get(colInfosIndex).getInternalName(), colInfosIndex);
}
}
}
}
/**
* Processor for Select operator.
*/
public static class SelectInferrer extends DefaultInferrer implements NodeProcessor {
@Override
public Object process(Node nd, Stack stack, NodeProcessorCtx procCtx,
Object... nodeOutputs) throws SemanticException {
BucketingSortingCtx bctx = (BucketingSortingCtx)procCtx;
SelectOperator sop = (SelectOperator)nd;
if (sop.getNumParent() == 1 &&
sop.getParentOperators().get(0) instanceof ReduceSinkOperator) {
ReduceSinkOperator rs = (ReduceSinkOperator) sop.getParentOperators().get(0);
extractTraits(bctx, rs, sop);
return null;
}
Operator parent = getParent(stack);
// if this is a selStarNoCompute then this select operator
// is treated like a default operator, so just call the super classes
// process method.
if (sop.getConf().isSelStarNoCompute()) {
processForward(sop, bctx, parent);
return null;
}
List bucketCols = bctx.getBucketedCols(parent);
List sortCols = bctx.getSortedCols(parent);
List colInfos = sop.getSchema().getSignature();
if (bucketCols == null && sortCols == null) {
return null;
}
BucketCol[] newBucketCols = null;
SortCol[] newSortCols = null;
if (bucketCols != null) {
newBucketCols = new BucketCol[bucketCols.size()];
}
if (sortCols != null) {
newSortCols = new SortCol[sortCols.size()];
}
findBucketingSortingColumns(sop.getConf().getColList(), colInfos, bucketCols, sortCols,
newBucketCols, newSortCols);
setBucketingColsIfComplete(bctx, sop, newBucketCols);
setSortingColsIfComplete(bctx, sop, newSortCols);
return null;
}
}
/**
* Find the BucketSortCol which has colName as one of its aliases. Returns the index of that
* BucketSortCol, or -1 if none exist
* @param bucketSortCols
* @param colName
* @return
*/
private static int indexOfColName(List bucketSortCols, String colName) {
for (int index = 0; index < bucketSortCols.size(); index++) {
BucketSortCol bucketSortCol = bucketSortCols.get(index);
if (bucketSortCol.getNames().indexOf(colName) != -1) {
return index;
}
}
return -1;
}
/**
* This is used to construct new lists of bucketed columns where the order of the columns
* hasn't changed, only possibly the name
* @param bucketCols - input bucketed columns
* @param colInfos - List of column infos
* @return output bucketed columns
*/
private static List getNewBucketCols(List bucketCols,
List colInfos) {
List newBucketCols = new ArrayList(bucketCols.size());
for (int i = 0; i < bucketCols.size(); i++) {
BucketCol bucketCol = new BucketCol();
for (Integer index : bucketCols.get(i).getIndexes()) {
// The only time this condition should be false is in the case of dynamic partitioning
// where the data is bucketed on a dynamic partitioning column and the FileSinkOperator is
// being processed. In this case, the dynamic partition column will not appear in
// colInfos, and due to the limitations of dynamic partitioning, they will appear at the
// end of the input schema. Since the order of the columns hasn't changed, and no new
// columns have been added/removed, it is safe to assume that these will have indexes
// greater than or equal to colInfos.size().
if (index < colInfos.size()) {
bucketCol.addAlias(colInfos.get(index).getInternalName(), index);
} else {
return null;
}
}
newBucketCols.add(bucketCol);
}
return newBucketCols;
}
/**
* This is used to construct new lists of sorted columns where the order of the columns
* hasn't changed, only possibly the name
* @param bucketCols - input sorted columns
* @param colInfos - List of column infos
* @return output sorted columns
*/
private static List getNewSortCols(List sortCols, List colInfos) {
List newSortCols = new ArrayList(sortCols.size());
for (int i = 0; i < sortCols.size(); i++) {
SortCol sortCol = new SortCol(sortCols.get(i).getSortOrder());
for (Integer index : sortCols.get(i).getIndexes()) {
// The only time this condition should be false is in the case of dynamic partitioning
if (index < colInfos.size()) {
sortCol.addAlias(colInfos.get(index).getInternalName(), index);
} else {
return null;
}
}
newSortCols.add(sortCol);
}
return newSortCols;
}
/**
* Processor for FileSink operator.
*/
public static class FileSinkInferrer extends DefaultInferrer implements NodeProcessor {
@Override
public Object process(Node nd, Stack stack, NodeProcessorCtx procCtx,
Object... nodeOutputs) throws SemanticException {
BucketingSortingCtx bctx = (BucketingSortingCtx)procCtx;
FileSinkOperator fop = (FileSinkOperator)nd;
Operator parent = getParent(stack);
List bucketCols = bctx.getBucketedCols(parent);
List colInfos = fop.getSchema().getSignature();
// Set the inferred bucket columns for the file this FileSink produces
if (bucketCols != null) {
List newBucketCols = getNewBucketCols(bucketCols, colInfos);
bctx.getBucketedColsByDirectory().put(fop.getConf().getDirName().toString(), newBucketCols);
bctx.setBucketedCols(fop, newBucketCols);
}
List sortCols = bctx.getSortedCols(parent);
// Set the inferred sort columns for the file this FileSink produces
if (sortCols != null) {
List newSortCols = getNewSortCols(sortCols, colInfos);
bctx.getSortedColsByDirectory().put(fop.getConf().getDirName().toString(), newSortCols);
bctx.setSortedCols(fop, newSortCols);
}
return null;
}
}
static void extractTraits(BucketingSortingCtx bctx, ReduceSinkOperator rop, Operator childop)
throws SemanticException {
List outputValues = Collections.emptyList();
if (childop instanceof SelectOperator) {
SelectDesc select = ((SelectOperator)childop).getConf();
outputValues = ExprNodeDescUtils.backtrack(select.getColList(), childop, rop);
}
if (outputValues.isEmpty()) {
return;
}
// Go through the set of partition columns, and find their representatives in the values
// These represent the bucketed columns
List bucketCols = extractBucketCols(rop, outputValues);
// Go through the set of key columns, and find their representatives in the values
// These represent the sorted columns
List sortCols = extractSortCols(rop, outputValues);
List colInfos = childop.getSchema().getSignature();
if (!bucketCols.isEmpty()) {
List newBucketCols = getNewBucketCols(bucketCols, colInfos);
bctx.setBucketedCols(childop, newBucketCols);
}
if (!sortCols.isEmpty()) {
List newSortCols = getNewSortCols(sortCols, colInfos);
bctx.setSortedCols(childop, newSortCols);
}
}
static List extractBucketCols(ReduceSinkOperator rop, List outputValues) {
List bucketCols = new ArrayList();
for (ExprNodeDesc partitionCol : rop.getConf().getPartitionCols()) {
if (!(partitionCol instanceof ExprNodeColumnDesc)) {
return Collections.emptyList();
}
int index = ExprNodeDescUtils.indexOf(partitionCol, outputValues);
if (index < 0) {
return Collections.emptyList();
}
bucketCols.add(new BucketCol(((ExprNodeColumnDesc) partitionCol).getColumn(), index));
}
// If the partition columns can't all be found in the values then the data is not bucketed
return bucketCols;
}
static List extractSortCols(ReduceSinkOperator rop, List outputValues) {
String sortOrder = rop.getConf().getOrder();
List sortCols = new ArrayList();
ArrayList keyCols = rop.getConf().getKeyCols();
for (int i = 0; i < keyCols.size(); i++) {
ExprNodeDesc keyCol = keyCols.get(i);
if (!(keyCol instanceof ExprNodeColumnDesc)) {
break;
}
int index = ExprNodeDescUtils.indexOf(keyCol, outputValues);
if (index < 0) {
break;
}
sortCols.add(new SortCol(((ExprNodeColumnDesc) keyCol).getColumn(), index, sortOrder.charAt(i)));
}
// If the sorted columns can't all be found in the values then the data is only sorted on
// the columns seen up until now
return sortCols;
}
/**
* Processor for GroupByOperator, the special case where it follows a ForwardOperator
*
* There is a multi group by optimization which puts multiple group by operators in a
* reducer when they share the same keys and are part of a multi insert query.
*
* In this case the tree should look like
* Group By Operator
* /
* ReduceSinkOperator - ForwardOperator --- ...
* \
* GroupByOperator
*
*/
public static class MultiGroupByInferrer extends GroupByInferrer implements NodeProcessor {
@Override
public Object process(Node nd, Stack stack, NodeProcessorCtx procCtx,
Object... nodeOutputs) throws SemanticException {
BucketingSortingCtx bctx = (BucketingSortingCtx)procCtx;
GroupByOperator gop = (GroupByOperator)nd;
if (gop.getParentOperators().size() != 1) {
return null;
}
Operator fop = gop.getParentOperators().get(0);
// The caller of this method should guarantee this
assert(fop instanceof ForwardOperator);
if (fop.getParentOperators().size() != 1) {
return null;
}
Operator rop = fop.getParentOperators().get(0);
// The caller of this method should guarantee this
assert(rop instanceof ReduceSinkOperator);
processGroupByReduceSink((ReduceSinkOperator) rop, gop, bctx);
processForward(fop, bctx, rop);
return processGroupBy(fop, gop, bctx);
}
}
/**
* Processor for GroupBy operator.
*
* This handles the standard use of a group by operator, the tree should look like
*
* ReduceSinkOperator --- GroupByOperator
*
* It is up to the caller to guarantee the tree matches this pattern.
*/
public static class GroupByInferrer extends DefaultInferrer implements NodeProcessor {
@Override
public Object process(Node nd, Stack stack, NodeProcessorCtx procCtx,
Object... nodeOutputs) throws SemanticException {
BucketingSortingCtx bctx = (BucketingSortingCtx)procCtx;
GroupByOperator gop = (GroupByOperator)nd;
// As of writing this, there is no case where this could be false, this is just protection
// from possible future changes
if (gop.getParentOperators().size() != 1) {
return null;
}
Operator rop = gop.getParentOperators().get(0);
// The caller of this method should guarantee this
assert(rop instanceof ReduceSinkOperator);
processGroupByReduceSink((ReduceSinkOperator) rop, gop, bctx);
return processGroupBy(rop , gop, bctx);
}
/**
* Process the ReduceSinkOperator preceding a GroupByOperator to determine which columns
* are bucketed and sorted.
*
* @param rop
* @param gop
* @param bctx
*/
protected void processGroupByReduceSink(ReduceSinkOperator rop, GroupByOperator gop,
BucketingSortingCtx bctx){
GroupByDesc groupByDesc = gop.getConf();
String sortOrder = rop.getConf().getOrder();
List bucketCols = new ArrayList();
List sortCols = new ArrayList();
assert rop.getConf().getKeyCols().size() <= rop.getSchema().getSignature().size();
// Group by operators select the key cols, so no need to find them in the values
for (int i = 0; i < rop.getConf().getKeyCols().size(); i++) {
if (groupByDesc.pruneGroupingSetId() && groupByDesc.getGroupingSetPosition() == i) {
continue;
}
String colName = rop.getSchema().getSignature().get(i).getInternalName();
bucketCols.add(new BucketCol(colName, i));
sortCols.add(new SortCol(colName, i, sortOrder.charAt(i)));
}
bctx.setBucketedCols(rop, bucketCols);
bctx.setSortedCols(rop, sortCols);
}
/**
* Process a GroupByOperator to determine which if any columns the output is bucketed and
* sorted by, assumes the columns output by the parent which are bucketed and sorted have
* already been determined.
*
* @param parent
* @param gop
* @param bctx
* @return
*/
protected Object processGroupBy(Operator parent, GroupByOperator gop,
BucketingSortingCtx bctx) {
List bucketCols = bctx.getBucketedCols(parent);
List sortCols = bctx.getSortedCols(parent);
List colInfos = gop.getSchema().getSignature();
if (bucketCols == null) {
assert sortCols == null;
return null;
}
if (bucketCols.isEmpty()) {
assert sortCols.isEmpty();
return null;
}
BucketCol[] newBucketCols = new BucketCol[bucketCols.size()];
SortCol[] newSortCols = new SortCol[sortCols.size()];
findBucketingSortingColumns(gop.getConf().getKeys(), colInfos, bucketCols, sortCols,
newBucketCols, newSortCols);
setBucketingColsIfComplete(bctx, gop, newBucketCols);
setSortingColsIfComplete(bctx, gop, newSortCols);
return null;
}
}
/**
* Filter processor
*/
public static class ForwardingInferrer extends DefaultInferrer implements NodeProcessor {
@SuppressWarnings("unchecked")
@Override
public Object process(Node nd, Stack stack, NodeProcessorCtx procCtx,
Object... nodeOutputs) throws SemanticException {
processForward((Operator)nd, (BucketingSortingCtx)procCtx,
getParent(stack));
return null;
}
}
public static NodeProcessor getDefaultProc() {
return new DefaultInferrer();
}
public static NodeProcessor getJoinProc() {
return new JoinInferrer();
}
public static NodeProcessor getSelProc() {
return new SelectInferrer();
}
public static NodeProcessor getGroupByProc() {
return new GroupByInferrer();
}
public static NodeProcessor getFileSinkProc() {
return new FileSinkInferrer();
}
public static NodeProcessor getFilterProc() {
return new ForwardingInferrer();
}
public static NodeProcessor getLimitProc() {
return new ForwardingInferrer();
}
public static NodeProcessor getLateralViewForwardProc() {
return new ForwardingInferrer();
}
public static NodeProcessor getLateralViewJoinProc() {
return new ForwardingInferrer();
}
public static NodeProcessor getForwardProc() {
return new ForwardingInferrer();
}
public static NodeProcessor getMultiGroupByProc() {
return new MultiGroupByInferrer();
}
}
