rohangarg commented on code in PR #15897: URL: https://github.com/apache/druid/pull/15897#discussion_r1505765390
########## sql/src/main/java/org/apache/druid/sql/calcite/external/TableAppendMacro.java: ########## @@ -0,0 +1,344 @@ +/* + * 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.druid.sql.calcite.external; + +import com.google.common.collect.ImmutableList; +import org.apache.calcite.plan.RelOptTable; +import org.apache.calcite.rel.type.RelDataType; +import org.apache.calcite.rel.type.RelDataTypeFactory; +import org.apache.calcite.rex.RexNode; +import org.apache.calcite.schema.TranslatableTable; +import org.apache.calcite.sql.SqlCall; +import org.apache.calcite.sql.SqlCallBinding; +import org.apache.calcite.sql.SqlIdentifier; +import org.apache.calcite.sql.SqlKind; +import org.apache.calcite.sql.SqlNode; +import org.apache.calcite.sql.SqlOperandCountRange; +import org.apache.calcite.sql.SqlOperator; +import org.apache.calcite.sql.SqlOperatorBinding; +import org.apache.calcite.sql.parser.SqlParserPos; +import org.apache.calcite.sql.type.ReturnTypes; +import org.apache.calcite.sql.type.SqlOperandCountRanges; +import org.apache.calcite.sql.type.SqlOperandMetadata; +import org.apache.calcite.sql.type.SqlTypeFamily; +import org.apache.calcite.sql.type.SqlTypeName; +import org.apache.calcite.sql.validate.SqlUserDefinedTableMacro; +import org.apache.calcite.sql.validate.SqlValidator; +import org.apache.calcite.sql.validate.SqlValidatorCatalogReader; +import org.apache.calcite.sql.validate.SqlValidatorTable; +import org.apache.druid.java.util.common.StringUtils; +import org.apache.druid.query.DataSource; +import org.apache.druid.query.UnionDataSource; +import org.apache.druid.segment.column.ColumnType; +import org.apache.druid.segment.column.RowSignature; +import org.apache.druid.segment.column.RowSignature.Builder; +import org.apache.druid.server.security.Action; +import org.apache.druid.server.security.Resource; +import org.apache.druid.server.security.ResourceAction; +import org.apache.druid.server.security.ResourceType; +import org.apache.druid.sql.calcite.expression.AuthorizableOperator; +import org.apache.druid.sql.calcite.expression.DruidExpression; +import org.apache.druid.sql.calcite.expression.SqlOperatorConversion; +import org.apache.druid.sql.calcite.planner.DruidSqlValidator; +import org.apache.druid.sql.calcite.planner.PlannerContext; +import org.apache.druid.sql.calcite.table.DatasourceMetadata; +import org.apache.druid.sql.calcite.table.DatasourceTable; +import org.apache.druid.sql.calcite.table.DatasourceTable.EffectiveMetadata; +import org.checkerframework.checker.nullness.qual.Nullable; + +import java.util.ArrayList; +import java.util.HashSet; +import java.util.LinkedHashMap; +import java.util.List; +import java.util.Map; +import java.util.Map.Entry; +import java.util.Set; + +/** + * Dynamic table append. + * + * Enables to use: TABLE(APPEND('t1','t2')); which will provide a union view of the operand tables. + */ +public class TableAppendMacro extends SqlUserDefinedTableMacro implements AuthorizableOperator +{ + + public static final OperatorConversion OPERATOR_CONVERSION = new OperatorConversion(); + public static final SqlOperator APPEND_TABLE_MACRO = new TableAppendMacro(); + + private static class OperatorConversion implements SqlOperatorConversion + { + public static final String FUNCTION_NAME = "APPEND"; + + public OperatorConversion() + { + } + + @Override + public SqlOperator calciteOperator() + { + return APPEND_TABLE_MACRO; + } + + @Override + public DruidExpression toDruidExpression(PlannerContext plannerContext, RowSignature rowSignature, RexNode rexNode) + { + throw new IllegalStateException(); + } + } + + private TableAppendMacro() + { + super( + new SqlIdentifier(OperatorConversion.FUNCTION_NAME, SqlParserPos.ZERO), + SqlKind.OTHER_FUNCTION, + ReturnTypes.CURSOR, + null, + new OperandMetadata(), + null + ); + } + + private static class OperandMetadata implements SqlOperandMetadata + { + @Override + public boolean checkOperandTypes(SqlCallBinding callBinding, boolean throwOnFailure) + { + for (int i = 0; i < callBinding.getOperandCount(); i++) { + SqlNode operand = callBinding.operand(i); + if (!callBinding.isOperandLiteral(i, false)) { + if (throwOnFailure) { + throw DruidSqlValidator.buildCalciteContextException( + "All arguments to APPEND should be literal strings. " + + "Argument #" + i + " is not literal", + operand + ); + } else { + return false; + } + } + + SqlTypeName typeName = callBinding.getOperandType(i).getSqlTypeName(); + if (!SqlTypeFamily.CHARACTER.getTypeNames().contains(typeName)) { + if (throwOnFailure) { + throw DruidSqlValidator.buildCalciteContextException( + "All arguments to APPEND should be literal strings. " + + "Argument #" + i + " is not string", + operand + ); + } else { + return false; + } + } + } + return true; + } + + @Override + public SqlOperandCountRange getOperandCountRange() + { + return SqlOperandCountRanges.from(1); + } + + @Override + public String getAllowedSignatures(SqlOperator op, String opName) + { + return "APPEND( <TABLE_NAME>[, <TABLE_NAME> ...] )"; + } + + @Override + public List<RelDataType> paramTypes(RelDataTypeFactory typeFactory) + { + RelDataType t = typeFactory.createSqlType(SqlTypeName.VARCHAR); + return ImmutableList.<RelDataType>builder().add(t, t).build(); + } + + @Override + public List<String> paramNames() + { + return ImmutableList.<String>builder().add("tableName", "tableName").build(); + } + } + + @Override + public List<String> getParamNames() + { + return ImmutableList.<String>builder().add("tableName", "tableName").build(); + } + + @Override + public TranslatableTable getTable(SqlOperatorBinding operatorBinding) + { + SqlCallBinding callBinding = (SqlCallBinding) operatorBinding; + SqlValidator validator = callBinding.getValidator(); + + List<TableOperand> tables = getTables(callBinding, validator.getCatalogReader()); + AppendDatasourceMetadata metadata = buildUnionDataSource(tables); + return new DatasourceTable( + metadata.values, + metadata, + EffectiveMetadata.of(metadata.values) + ); + } + + static class TableOperand + { + private final SqlNode sqlOperand; + private final SqlValidatorTable table; + + public TableOperand(SqlNode sqlOperand, SqlValidatorTable table) + { + this.sqlOperand = sqlOperand; + this.table = table; + } + + public RelOptTable getRelOptTable() + { + return table.unwrapOrThrow(RelOptTable.class); + } + + public DatasourceTable getDataSourceTable() + { + return table.unwrapOrThrow(DatasourceTable.class); + } + + public RowSignature getRowSignature() + { + return getDataSourceTable().getRowSignature(); + } + + public DataSource getDataSource() + { + return getDataSourceTable().getDataSource(); + } + } + + private List<TableOperand> getTables(SqlCallBinding callBinding, SqlValidatorCatalogReader catalogReader) + { + List<TableOperand> tables = new ArrayList<>(); + for (int i = 0; i < callBinding.getOperandCount(); i++) { + if (!callBinding.isOperandLiteral(i, false)) { + throw DruidSqlValidator.buildCalciteContextException( + "All arguments of call to macro " + + "APPEND should be literal. Actual argument #" + + i + " is not literal", + callBinding.operand(i) + ); + } + @Nullable + String tableName = callBinding.getOperandLiteralValue(i, String.class); + ImmutableList<String> tableNameList = ImmutableList.<String>builder().add(tableName).build(); + SqlValidatorTable table = catalogReader.getTable(tableNameList); Review Comment: Thanks for the explanation - it makes sense to only support persisted tables for now. This can be considered when the execution engine supports CTE + table union easily. We can mention this caveat in the documentation for the users though. -- 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. 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