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Posted to commits@pinot.apache.org by GitBox <gi...@apache.org> on 2020/08/01 00:00:25 UTC
[GitHub] [incubator-pinot] Jackie-Jiang commented on a change in pull request #5766: Adding distinct count support based on bitmap
Jackie-Jiang commented on a change in pull request #5766:
URL: https://github.com/apache/incubator-pinot/pull/5766#discussion_r463885786
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File path: pinot-core/src/main/java/org/apache/pinot/core/query/aggregation/function/DistinctCountBitmapAggregationFunction.java
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@@ -0,0 +1,409 @@
+/**
+ * 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.pinot.core.query.aggregation.function;
+
+import java.util.Map;
+import org.apache.pinot.common.function.AggregationFunctionType;
+import org.apache.pinot.common.utils.DataSchema.ColumnDataType;
+import org.apache.pinot.core.common.BlockValSet;
+import org.apache.pinot.core.common.ObjectSerDeUtils;
+import org.apache.pinot.core.query.aggregation.AggregationResultHolder;
+import org.apache.pinot.core.query.aggregation.ObjectAggregationResultHolder;
+import org.apache.pinot.core.query.aggregation.groupby.GroupByResultHolder;
+import org.apache.pinot.core.query.aggregation.groupby.ObjectGroupByResultHolder;
+import org.apache.pinot.core.query.request.context.ExpressionContext;
+import org.apache.pinot.core.segment.index.readers.Dictionary;
+import org.apache.pinot.spi.data.FieldSpec.DataType;
+import org.roaringbitmap.PeekableIntIterator;
+import org.roaringbitmap.RoaringBitmap;
+
+
+public class DistinctCountBitmapAggregationFunction extends BaseSingleInputAggregationFunction<RoaringBitmap, Integer> {
+ protected Dictionary _dictionary;
+
+ public DistinctCountBitmapAggregationFunction(ExpressionContext expression) {
+ super(expression);
+ }
+
+ @Override
+ public AggregationFunctionType getType() {
+ return AggregationFunctionType.DISTINCTCOUNTBITMAP;
+ }
+
+ @Override
+ public void accept(AggregationFunctionVisitorBase visitor) {
+ visitor.visit(this);
+ }
+
+ @Override
+ public AggregationResultHolder createAggregationResultHolder() {
+ return new ObjectAggregationResultHolder();
+ }
+
+ @Override
+ public GroupByResultHolder createGroupByResultHolder(int initialCapacity, int maxCapacity) {
+ return new ObjectGroupByResultHolder(initialCapacity, maxCapacity);
+ }
+
+ @Override
+ public void aggregate(int length, AggregationResultHolder aggregationResultHolder,
+ Map<ExpressionContext, BlockValSet> blockValSetMap) {
+ BlockValSet blockValSet = blockValSetMap.get(_expression);
+
+ // Treat BYTES value as serialized RoaringBitmap
+ DataType valueType = blockValSet.getValueType();
+ if (valueType == DataType.BYTES) {
+ byte[][] bytesValues = blockValSet.getBytesValuesSV();
+ RoaringBitmap bitmap = aggregationResultHolder.getResult();
+ if (bitmap != null) {
+ for (int i = 0; i < length; i++) {
+ bitmap.or(ObjectSerDeUtils.ROARING_BITMAP_SER_DE.deserialize(bytesValues[i]));
+ }
+ } else {
+ bitmap = ObjectSerDeUtils.ROARING_BITMAP_SER_DE.deserialize(bytesValues[0]);
+ aggregationResultHolder.setValue(bitmap);
+ for (int i = 1; i < length; i++) {
+ bitmap.or(ObjectSerDeUtils.ROARING_BITMAP_SER_DE.deserialize(bytesValues[i]));
+ }
+ }
+ return;
+ }
+
+ // For dictionary-encoded expression, store dictionary ids into the bitmap
+ RoaringBitmap bitmap = getBitmap(aggregationResultHolder);
+ Dictionary dictionary = blockValSet.getDictionary();
+ if (dictionary != null) {
+ _dictionary = dictionary;
+ int[] dictIds = blockValSet.getDictionaryIdsSV();
+ bitmap.addN(dictIds, 0, length);
+ return;
+ }
+
+ // For non-dictionary-encoded expression, store hash code of the values into the bitmap
+ switch (valueType) {
+ case INT:
+ int[] intValues = blockValSet.getIntValuesSV();
+ bitmap.addN(intValues, 0, length);
+ break;
+ case LONG:
+ long[] longValues = blockValSet.getLongValuesSV();
+ for (int i = 0; i < length; i++) {
+ bitmap.add(Long.hashCode(longValues[i]));
+ }
+ break;
+ case FLOAT:
+ float[] floatValues = blockValSet.getFloatValuesSV();
+ for (int i = 0; i < length; i++) {
+ bitmap.add(Float.hashCode(floatValues[i]));
+ }
+ break;
+ case DOUBLE:
+ double[] doubleValues = blockValSet.getDoubleValuesSV();
+ for (int i = 0; i < length; i++) {
+ bitmap.add(Double.hashCode(doubleValues[i]));
+ }
+ break;
+ case STRING:
+ String[] stringValues = blockValSet.getStringValuesSV();
+ for (int i = 0; i < length; i++) {
+ bitmap.add(stringValues[i].hashCode());
+ }
+ break;
+ default:
+ throw new IllegalStateException(
+ "Illegal data type for DISTINCT_COUNT_BITMAP aggregation function: " + valueType);
+ }
+ }
+
+ @Override
+ public void aggregateGroupBySV(int length, int[] groupKeyArray, GroupByResultHolder groupByResultHolder,
+ Map<ExpressionContext, BlockValSet> blockValSetMap) {
+ BlockValSet blockValSet = blockValSetMap.get(_expression);
+
+ // Treat BYTES value as serialized RoaringBitmap
+ DataType valueType = blockValSet.getValueType();
+ if (valueType == DataType.BYTES) {
+ byte[][] bytesValues = blockValSet.getBytesValuesSV();
+ for (int i = 0; i < length; i++) {
+ RoaringBitmap value = ObjectSerDeUtils.ROARING_BITMAP_SER_DE.deserialize(bytesValues[i]);
+ int groupKey = groupKeyArray[i];
+ RoaringBitmap bitmap = groupByResultHolder.getResult(groupKey);
+ if (bitmap != null) {
+ bitmap.or(value);
+ } else {
+ groupByResultHolder.setValueForKey(groupKey, value);
+ }
+ }
+ return;
+ }
+
+ // For dictionary-encoded expression, store dictionary ids into the bitmap
+ Dictionary dictionary = blockValSet.getDictionary();
+ if (dictionary != null) {
+ _dictionary = dictionary;
+ int[] dictIds = blockValSet.getDictionaryIdsSV();
+ for (int i = 0; i < length; i++) {
+ getBitmap(groupByResultHolder, groupKeyArray[i]).add(dictIds[i]);
+ }
+ return;
+ }
+
+ // For non-dictionary-encoded expression, store hash code of the values into the bitmap
+ switch (valueType) {
+ case INT:
+ int[] intValues = blockValSet.getIntValuesSV();
+ for (int i = 0; i < length; i++) {
+ getBitmap(groupByResultHolder, groupKeyArray[i]).add(intValues[i]);
+ }
+ break;
+ case LONG:
+ long[] longValues = blockValSet.getLongValuesSV();
+ for (int i = 0; i < length; i++) {
+ getBitmap(groupByResultHolder, groupKeyArray[i]).add(Long.hashCode(longValues[i]));
+ }
+ break;
+ case FLOAT:
+ float[] floatValues = blockValSet.getFloatValuesSV();
+ for (int i = 0; i < length; i++) {
+ getBitmap(groupByResultHolder, groupKeyArray[i]).add(Float.hashCode(floatValues[i]));
+ }
+ break;
+ case DOUBLE:
+ double[] doubleValues = blockValSet.getDoubleValuesSV();
+ for (int i = 0; i < length; i++) {
+ getBitmap(groupByResultHolder, groupKeyArray[i]).add(Double.hashCode(doubleValues[i]));
+ }
+ break;
+ case STRING:
+ String[] stringValues = blockValSet.getStringValuesSV();
+ for (int i = 0; i < length; i++) {
+ getBitmap(groupByResultHolder, groupKeyArray[i]).add(stringValues[i].hashCode());
+ }
+ break;
+ default:
+ throw new IllegalStateException(
+ "Illegal data type for DISTINCT_COUNT_BITMAP aggregation function: " + valueType);
+ }
+ }
+
+ @Override
+ public void aggregateGroupByMV(int length, int[][] groupKeysArray, GroupByResultHolder groupByResultHolder,
+ Map<ExpressionContext, BlockValSet> blockValSetMap) {
+ BlockValSet blockValSet = blockValSetMap.get(_expression);
+
+ // Treat BYTES value as serialized RoaringBitmap
+ DataType valueType = blockValSet.getValueType();
+ if (valueType == DataType.BYTES) {
+ byte[][] bytesValues = blockValSet.getBytesValuesSV();
+ for (int i = 0; i < length; i++) {
+ RoaringBitmap value = ObjectSerDeUtils.ROARING_BITMAP_SER_DE.deserialize(bytesValues[i]);
+ for (int groupKey : groupKeysArray[i]) {
+ RoaringBitmap bitmap = groupByResultHolder.getResult(groupKey);
+ if (bitmap != null) {
+ bitmap.or(value);
+ } else {
+ // Clone a bitmap for the group
+ groupByResultHolder.setValueForKey(groupKey, value.clone());
+ }
+ }
+ }
+ return;
+ }
+
+ // For dictionary-encoded expression, store dictionary ids into the bitmap
+ Dictionary dictionary = blockValSet.getDictionary();
Review comment:
Did a performance comparison on IntOpenHashSet vs RoaringBitmap vs BitSet, and find that the performance: BitSet > RoaringBitmap >> IntOpenHashSet. So here we use RoaringBitmap for good performance + good compression.
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