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Posted to issues@iceberg.apache.org by GitBox <gi...@apache.org> on 2020/07/22 16:56:11 UTC
[GitHub] [iceberg] rdblue commented on a change in pull request #933: [WIP] Mapred input format
rdblue commented on a change in pull request #933:
URL: https://github.com/apache/iceberg/pull/933#discussion_r458941801
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File path: mr/src/main/java/org/apache/iceberg/mr/mapred/IcebergFilterFactory.java
##########
@@ -0,0 +1,151 @@
+/*
+ * 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.iceberg.mr.mapred;
+
+import java.math.BigDecimal;
+import java.sql.Date;
+import java.sql.Timestamp;
+import java.util.List;
+import org.apache.hadoop.hive.ql.io.sarg.ExpressionTree;
+import org.apache.hadoop.hive.ql.io.sarg.PredicateLeaf;
+import org.apache.hadoop.hive.ql.io.sarg.SearchArgument;
+import org.apache.hadoop.hive.serde2.io.HiveDecimalWritable;
+import org.apache.iceberg.expressions.Expression;
+import org.apache.iceberg.expressions.Expressions;
+
+import static org.apache.iceberg.expressions.Expressions.and;
+import static org.apache.iceberg.expressions.Expressions.equal;
+import static org.apache.iceberg.expressions.Expressions.greaterThanOrEqual;
+import static org.apache.iceberg.expressions.Expressions.in;
+import static org.apache.iceberg.expressions.Expressions.isNull;
+import static org.apache.iceberg.expressions.Expressions.lessThan;
+import static org.apache.iceberg.expressions.Expressions.lessThanOrEqual;
+import static org.apache.iceberg.expressions.Expressions.not;
+import static org.apache.iceberg.expressions.Expressions.notNull;
+import static org.apache.iceberg.expressions.Expressions.or;
+
+public class IcebergFilterFactory {
+
+ private IcebergFilterFactory() {}
+
+ public static Expression generateFilterExpression(SearchArgument sarg) {
+ return translate(sarg.getExpression(), sarg.getLeaves());
+ }
+
+ /**
+ * Recursive method to traverse down the ExpressionTree to evaluate each expression and its leaf nodes.
+ * @param tree Current ExpressionTree where the 'top' node is being evaluated.
+ * @param leaves List of all leaf nodes within the tree.
+ * @return Expression that is translated from the Hive SearchArgument.
+ */
+ private static Expression translate(ExpressionTree tree, List<PredicateLeaf> leaves) {
+ List<ExpressionTree> childNodes = tree.getChildren();
+ switch (tree.getOperator()) {
+ case OR:
+ Expression orResult = Expressions.alwaysFalse();
+ for (ExpressionTree child : childNodes) {
+ orResult = or(orResult, translate(child, leaves));
+ }
+ return orResult;
+ case AND:
+ Expression result = Expressions.alwaysTrue();
+ for (ExpressionTree child : childNodes) {
+ result = and(result, translate(child, leaves));
+ }
+ return result;
+ case NOT:
+ return not(translate(tree.getChildren().get(0), leaves));
+ case LEAF:
+ return translateLeaf(leaves.get(tree.getLeaf()));
+ case CONSTANT:
+ //We are unsure of how the CONSTANT case works, so using the approach of:
+ //https://github.com/apache/hive/blob/master/ql/src/java/org/apache/hadoop/hive/ql/io/parquet/read/
+ // ParquetFilterPredicateConverter.java#L116
+ throw new UnsupportedOperationException("CONSTANT operator is not supported");
+ default:
+ throw new IllegalStateException("Unknown operator: " + tree.getOperator());
+ }
+ }
+
+ /**
+ * Translate leaf nodes from Hive operator to Iceberg operator.
+ * @param leaf Leaf node
+ * @return Expression fully translated from Hive PredicateLeaf
+ */
+ private static Expression translateLeaf(PredicateLeaf leaf) {
+ String column = leaf.getColumnName();
+ switch (leaf.getOperator()) {
+ case EQUALS:
+ return equal(column, leafToIcebergType(leaf));
+ case NULL_SAFE_EQUALS:
+ return equal(notNull(column).ref().name(), leafToIcebergType(leaf)); //TODO: Unsure..
+ case LESS_THAN:
+ return lessThan(column, leafToIcebergType(leaf));
+ case LESS_THAN_EQUALS:
+ return lessThanOrEqual(column, leafToIcebergType(leaf));
+ case IN:
+ return in(column, hiveLiteralListToIcebergType(leaf.getLiteralList()));
+ case BETWEEN:
+ List<Object> icebergLiterals = hiveLiteralListToIcebergType(leaf.getLiteralList());
+ return and(greaterThanOrEqual(column, icebergLiterals.get(0)),
+ lessThanOrEqual(column, icebergLiterals.get(1)));
+ case IS_NULL:
+ return isNull(column);
+ default:
+ throw new IllegalStateException("Unknown operator: " + leaf.getOperator());
+ }
+ }
+
+ private static Object leafToIcebergType(PredicateLeaf leaf) {
+ switch (leaf.getType()) {
+ case LONG:
+ return leaf.getLiteral();
+ case FLOAT:
+ return leaf.getLiteral();
+ case STRING:
+ return leaf.getLiteral();
+ case DATE:
+ return ((Timestamp) leaf.getLiteral()).getTime();
+ case DECIMAL:
+ return BigDecimal.valueOf(((HiveDecimalWritable) leaf.getLiteral()).doubleValue());
+ case TIMESTAMP:
+ return ((Timestamp) leaf.getLiteral()).getTime();
Review comment:
We usually leave time zone handling to the engine. Engines should pass concrete values to Iceberg in expressions.
For example, a query might have a clause `WHERE ts > TIMESTAMP '...'`. It is the query engine's responsibility to determine what concrete value that timestamp actually represents. If `ts` is a timestamp without time zone, for example, the engine is responsible for converting the timestamp with time zone for comparison.
Iceberg should receive an unambiguous value to use in the comparison. Preferably, the value is in microseconds from epoch, but we can convert from alternative representations like millis + nanos.
##########
File path: mr/src/main/java/org/apache/iceberg/mr/mapred/IcebergFilterFactory.java
##########
@@ -0,0 +1,151 @@
+/*
+ * 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.iceberg.mr.mapred;
+
+import java.math.BigDecimal;
+import java.sql.Date;
+import java.sql.Timestamp;
+import java.util.List;
+import org.apache.hadoop.hive.ql.io.sarg.ExpressionTree;
+import org.apache.hadoop.hive.ql.io.sarg.PredicateLeaf;
+import org.apache.hadoop.hive.ql.io.sarg.SearchArgument;
+import org.apache.hadoop.hive.serde2.io.HiveDecimalWritable;
+import org.apache.iceberg.expressions.Expression;
+import org.apache.iceberg.expressions.Expressions;
+
+import static org.apache.iceberg.expressions.Expressions.and;
+import static org.apache.iceberg.expressions.Expressions.equal;
+import static org.apache.iceberg.expressions.Expressions.greaterThanOrEqual;
+import static org.apache.iceberg.expressions.Expressions.in;
+import static org.apache.iceberg.expressions.Expressions.isNull;
+import static org.apache.iceberg.expressions.Expressions.lessThan;
+import static org.apache.iceberg.expressions.Expressions.lessThanOrEqual;
+import static org.apache.iceberg.expressions.Expressions.not;
+import static org.apache.iceberg.expressions.Expressions.notNull;
+import static org.apache.iceberg.expressions.Expressions.or;
+
+public class IcebergFilterFactory {
+
+ private IcebergFilterFactory() {}
+
+ public static Expression generateFilterExpression(SearchArgument sarg) {
+ return translate(sarg.getExpression(), sarg.getLeaves());
+ }
+
+ /**
+ * Recursive method to traverse down the ExpressionTree to evaluate each expression and its leaf nodes.
+ * @param tree Current ExpressionTree where the 'top' node is being evaluated.
+ * @param leaves List of all leaf nodes within the tree.
+ * @return Expression that is translated from the Hive SearchArgument.
+ */
+ private static Expression translate(ExpressionTree tree, List<PredicateLeaf> leaves) {
+ List<ExpressionTree> childNodes = tree.getChildren();
+ switch (tree.getOperator()) {
+ case OR:
+ Expression orResult = Expressions.alwaysFalse();
+ for (ExpressionTree child : childNodes) {
+ orResult = or(orResult, translate(child, leaves));
+ }
+ return orResult;
+ case AND:
+ Expression result = Expressions.alwaysTrue();
+ for (ExpressionTree child : childNodes) {
+ result = and(result, translate(child, leaves));
+ }
+ return result;
+ case NOT:
+ return not(translate(tree.getChildren().get(0), leaves));
+ case LEAF:
+ return translateLeaf(leaves.get(tree.getLeaf()));
+ case CONSTANT:
+ //We are unsure of how the CONSTANT case works, so using the approach of:
+ //https://github.com/apache/hive/blob/master/ql/src/java/org/apache/hadoop/hive/ql/io/parquet/read/
+ // ParquetFilterPredicateConverter.java#L116
+ throw new UnsupportedOperationException("CONSTANT operator is not supported");
+ default:
+ throw new IllegalStateException("Unknown operator: " + tree.getOperator());
+ }
+ }
+
+ /**
+ * Translate leaf nodes from Hive operator to Iceberg operator.
+ * @param leaf Leaf node
+ * @return Expression fully translated from Hive PredicateLeaf
+ */
+ private static Expression translateLeaf(PredicateLeaf leaf) {
+ String column = leaf.getColumnName();
+ switch (leaf.getOperator()) {
+ case EQUALS:
+ return equal(column, leafToIcebergType(leaf));
+ case NULL_SAFE_EQUALS:
+ return equal(notNull(column).ref().name(), leafToIcebergType(leaf)); //TODO: Unsure..
+ case LESS_THAN:
+ return lessThan(column, leafToIcebergType(leaf));
+ case LESS_THAN_EQUALS:
+ return lessThanOrEqual(column, leafToIcebergType(leaf));
+ case IN:
+ return in(column, hiveLiteralListToIcebergType(leaf.getLiteralList()));
+ case BETWEEN:
+ List<Object> icebergLiterals = hiveLiteralListToIcebergType(leaf.getLiteralList());
+ return and(greaterThanOrEqual(column, icebergLiterals.get(0)),
+ lessThanOrEqual(column, icebergLiterals.get(1)));
+ case IS_NULL:
+ return isNull(column);
+ default:
+ throw new IllegalStateException("Unknown operator: " + leaf.getOperator());
+ }
+ }
+
+ private static Object leafToIcebergType(PredicateLeaf leaf) {
+ switch (leaf.getType()) {
+ case LONG:
+ return leaf.getLiteral();
+ case FLOAT:
+ return leaf.getLiteral();
+ case STRING:
+ return leaf.getLiteral();
+ case DATE:
+ return ((Timestamp) leaf.getLiteral()).getTime();
+ case DECIMAL:
+ return BigDecimal.valueOf(((HiveDecimalWritable) leaf.getLiteral()).doubleValue());
+ case TIMESTAMP:
+ return ((Timestamp) leaf.getLiteral()).getTime();
Review comment:
Iceberg leaves time zone handling to the engine. Engines should pass concrete values to Iceberg in expressions.
For example, a query might have a clause `WHERE ts > TIMESTAMP '...'`. It is the query engine's responsibility to determine what concrete value that timestamp actually represents. If `ts` is a timestamp without time zone, for example, the engine is responsible for converting the timestamp with time zone for comparison.
Iceberg should receive an unambiguous value to use in the comparison. Preferably, the value is in microseconds from epoch, but we can convert from alternative representations like millis + nanos.
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