| /* |
| * 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.drill.exec.planner.index; |
| |
| import org.apache.calcite.rel.RelCollation; |
| import org.apache.calcite.rel.RelFieldCollation; |
| import org.apache.calcite.rel.RelFieldCollation.NullDirection; |
| import org.apache.drill.common.expression.LogicalExpression; |
| |
| import java.util.Collection; |
| import java.util.List; |
| import java.util.Map; |
| |
| /** |
| * Top level interface used to define an index. |
| */ |
| public interface IndexDefinition { |
| /** |
| * Types of an index: PRIMARY_KEY_INDEX, NATIVE_SECONDARY_INDEX, EXTERNAL_SECONDARY_INDEX |
| */ |
| static enum IndexType { |
| PRIMARY_KEY_INDEX, |
| NATIVE_SECONDARY_INDEX, |
| EXTERNAL_SECONDARY_INDEX |
| }; |
| |
| /** |
| * Check to see if the field name is an index column and if so return the ordinal position in the index |
| * @param path The field path you want to compare to index column names. |
| * @return Return ordinal of the indexed column if valid, otherwise return -1 |
| */ |
| int getIndexColumnOrdinal(LogicalExpression path); |
| |
| /** |
| * Get the name of the index |
| */ |
| String getIndexName(); |
| |
| /** |
| * Check if this index 'covers' all the columns specified in the supplied list of columns |
| * @param columns |
| * @return True for covering index, False for non-covering |
| */ |
| boolean isCoveringIndex(List<LogicalExpression> columns); |
| |
| /** |
| * Check if this index have all the columns specified in the supplied list of columns indexed |
| * @param columns |
| * @return True if all fields are indexed, False for some or all fields is not indexed |
| */ |
| boolean allColumnsIndexed(Collection<LogicalExpression> columns); |
| |
| /** |
| * Check if this index has some columns specified in the supplied list of columns indexed |
| * @param columns |
| * @return True if some fields are indexed, False if none of the fields are indexed |
| */ |
| boolean someColumnsIndexed(Collection<LogicalExpression> columns); |
| |
| /** |
| * Get the list of columns (typically 1 column) that constitute the row key (primary key) |
| * @return |
| */ |
| List<LogicalExpression> getRowKeyColumns(); |
| |
| /** |
| * Get the name of the table this index is associated with |
| */ |
| String getTableName(); |
| |
| /** |
| * Get the type of this index based on {@link IndexType} |
| * @return one of the values in {@link IndexType} |
| */ |
| IndexType getIndexType(); |
| |
| /** |
| * Get the list of columns in the index key. |
| */ |
| List<LogicalExpression> getIndexColumns(); |
| |
| /** |
| * Get the list of columns that are in the 'included' or 'covered' fields. |
| */ |
| List<LogicalExpression> getNonIndexColumns(); |
| |
| /** |
| * Get the collation property (physical ordering) of the index. |
| */ |
| RelCollation getCollation(); |
| |
| /** |
| * Get a mapping of the LogicalExpresion/SchemaPath to its field collation |
| * - e.g Ascending/Descending, Nulls First/Nulls Last |
| */ |
| Map<LogicalExpression, RelFieldCollation> getCollationMap(); |
| |
| /** |
| * Get the nulls ordering of this index |
| * @return True, if nulls first. False otherwise |
| */ |
| NullDirection getNullsOrderingDirection(); |
| |
| } |