cbalci commented on a change in pull request #6383: URL: https://github.com/apache/incubator-pinot/pull/6383#discussion_r549888366
########## File path: pinot-core/src/main/java/org/apache/pinot/core/operator/transform/function/LookupTransformFunction.java ########## @@ -0,0 +1,332 @@ +/** + * 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.operator.transform.function; + +import java.util.Arrays; +import java.util.List; +import java.util.Map; +import java.util.ArrayList; +import com.google.common.base.Preconditions; +import org.apache.commons.lang3.ArrayUtils; +import org.apache.pinot.core.common.DataSource; +import org.apache.pinot.core.data.manager.offline.DimensionTableDataManager; +import org.apache.pinot.core.operator.blocks.ProjectionBlock; +import org.apache.pinot.core.operator.transform.TransformResultMetadata; +import org.apache.pinot.spi.data.FieldSpec; +import org.apache.pinot.spi.data.readers.GenericRow; +import org.apache.pinot.spi.data.readers.PrimaryKey; +import org.apache.pinot.spi.utils.builder.TableNameBuilder; + + +/** + * LOOKUP function takes 4 or more arguments: + * <ul> + * <li><b>TableName:</b> name of the dimension table which will be used</li> + * <li><b>ColumnName:</b> column name from the dimension table to look up</li> + * <li><b>JoinKey:</b> primary key column name for the dimension table. Note: Only primary key[s] are supported for JoinKey</li> + * <li><b>JoinValue:</b> primary key value</li> + * ...<br> + * *[If the dimension table has more then one primary keys (composite pk)] + * <li><b>JoinKey2</b></li> + * <li><b>JoinValue2</b></li> + * ... + * </ul> + * <br> + * Example: + * <pre>{@code SELECT + * baseballStats.playerName, + * baseballStats.teamID, + * LOOKUP('dimBaseballTeams', 'teamName', 'teamID', baseballStats.teamID) + * FROM + * baseballStats + * LIMIT 10}</pre> + * <br> + * Above example joins the dimension table 'baseballTeams' into regular table 'baseballStats' on 'teamID' key. + * Lookup function returns the value of the column 'teamName'. + */ +public class LookupTransformFunction extends BaseTransformFunction { + public static final String FUNCTION_NAME = "lookUp"; + + // Lookup parameters + private String _dimTableName; + private String _dimColumnName; + private final List<String> _joinKeys = new ArrayList<>(); + private final List<FieldSpec> _joinValueFieldSpecs = new ArrayList<>(); + private final List<TransformFunction> _joinValueFunctions = new ArrayList<>(); + + private DimensionTableDataManager _dataManager; + private FieldSpec _lookupColumnFieldSpec; + + @Override + public String getName() { + return FUNCTION_NAME; + } + + @Override + public void init(List<TransformFunction> arguments, Map<String, DataSource> dataSourceMap) { + // Check that there are correct number of arguments + Preconditions + .checkArgument(arguments.size() >= 4, + "At least 4 arguments are required for LOOKUP transform function: " + + "LOOKUP(TableName, ColumnName, JoinKey, JoinValue [, JoinKey2, JoinValue2 ...])"); + Preconditions + .checkArgument(arguments.size() % 2 == 0, "Should have the same number of JoinKey and JoinValue arguments"); + + TransformFunction dimTableNameFunction = arguments.get(0); + Preconditions.checkArgument(dimTableNameFunction instanceof LiteralTransformFunction, + "First argument must be a literal(string) representing the dimension table name"); + _dimTableName = TableNameBuilder.OFFLINE.tableNameWithType( + ((LiteralTransformFunction) dimTableNameFunction).getLiteral()); + + TransformFunction dimColumnFunction = arguments.get(1); + Preconditions.checkArgument(dimColumnFunction instanceof LiteralTransformFunction, + "Second argument must be a literal(string) representing the column name from dimension table to lookup"); + _dimColumnName = ((LiteralTransformFunction) dimColumnFunction).getLiteral(); + + List<TransformFunction> joinArguments = arguments.subList(2, arguments.size()); + int numJoinArguments = joinArguments.size(); + for (int i = 0; i < numJoinArguments / 2; i++) { + TransformFunction dimJoinKeyFunction = joinArguments.get((i * 2)); + Preconditions.checkArgument(dimJoinKeyFunction instanceof LiteralTransformFunction, + "JoinKey argument must be a literal(string) representing the primary key for the dimension table"); + _joinKeys.add(((LiteralTransformFunction) dimJoinKeyFunction).getLiteral()); + + TransformFunction factJoinValueFunction = joinArguments.get((i * 2) + 1); + TransformResultMetadata factJoinValueFunctionResultMetadata = factJoinValueFunction.getResultMetadata(); + Preconditions.checkArgument(factJoinValueFunctionResultMetadata.isSingleValue(), + "JoinValue argument must be a single value expression"); + _joinValueFunctions.add(factJoinValueFunction); + } + + // Validate lookup table and relevant columns + _dataManager = DimensionTableDataManager.getInstanceByTableName(_dimTableName); + Preconditions.checkArgument(_dataManager != null, + String.format("Dimension table does not exist: %s", _dimTableName)); + + _lookupColumnFieldSpec = _dataManager.getColumnFieldSpec(_dimColumnName); + Preconditions.checkArgument(_lookupColumnFieldSpec != null, + String.format("Column does not exist in dimension table: %s:%s", _dimTableName, _dimColumnName)); + + for (String joinKey : _joinKeys) { + FieldSpec pkColumnSpec = _dataManager.getColumnFieldSpec(joinKey); + Preconditions.checkArgument(pkColumnSpec != null, + String.format("Primary key column doesn't exist in dimension table: %s:%s", _dimTableName, joinKey)); + _joinValueFieldSpecs.add(pkColumnSpec); + } + + List<String> tablePrimaryKeyColumns = _dataManager.getPrimaryKeyColumns(); + Preconditions.checkArgument(_joinKeys.equals(tablePrimaryKeyColumns), + String.format("Provided join keys (%s) must be the same as table primary keys: %s", _joinKeys, + tablePrimaryKeyColumns)); + } + + @Override + public TransformResultMetadata getResultMetadata() { + return new TransformResultMetadata(_lookupColumnFieldSpec.getDataType(), + _lookupColumnFieldSpec.isSingleValueField(), false); + } + + private Object[] lookup(ProjectionBlock projectionBlock) { + int numPkColumns = _joinKeys.size(); + int numDocuments = projectionBlock.getNumDocs(); + Object[][] pkColumns = new Object[numPkColumns][]; + for (int i = 0; i < numPkColumns; i++) { + FieldSpec.DataType colType = _joinValueFieldSpecs.get(i).getDataType(); + TransformFunction tf = _joinValueFunctions.get(i); + switch (colType) { + case STRING: + pkColumns[i] = tf.transformToStringValuesSV(projectionBlock); + break; + case INT: + pkColumns[i] = ArrayUtils.toObject(tf.transformToIntValuesSV(projectionBlock)); + break; + case LONG: + pkColumns[i] = ArrayUtils.toObject(tf.transformToLongValuesSV(projectionBlock)); + break; + case FLOAT: + pkColumns[i] = ArrayUtils.toObject(tf.transformToFloatValuesSV(projectionBlock)); + break; + case DOUBLE: + pkColumns[i] = ArrayUtils.toObject(tf.transformToDoubleValuesSV(projectionBlock)); + break; + case BYTES: + byte[][] primitiveValues = tf.transformToBytesValuesSV(projectionBlock); + pkColumns[i] = new Byte[numDocuments][]; + for (int n = 0; n < numDocuments; n++) { + pkColumns[i][n] = ArrayUtils.toObject(primitiveValues[n]); + } + break; + default: + throw new IllegalStateException("Unknown column type for primary key"); + } + } + + Object[] resultSet = new Object[numDocuments]; + for (int i = 0; i < numDocuments; i++) { + // prepare pk + Object[] pkValues = new Object[numPkColumns]; Review comment: I can do something like: ```java Object[] resultSet = new Object[numDocuments]; Object[] pkValues = new Object[numPkColumns]; for (int i = 0; i < numDocuments; i++) { // prepare pk for (int j = 0; j < numPkColumns; j++) { pkValues[j] = pkColumns[j][i]; } // lookup GenericRow row = _dataManager.lookupRowByPrimaryKey(new PrimaryKey(pkValues)); if (row != null) { resultSet[i] = row.getValue(_dimColumnName); } } ``` I don't see much point in doing the same for `PrimaryKey` though. We will only be reusing the pointer which is not really helpful. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@pinot.apache.org For additional commands, e-mail: commits-h...@pinot.apache.org
