| /* |
| * 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. |
| */ |
| /** |
| * Provides a fluent schema builder. Handles all |
| * forms of Drill schemas, with emphasis on ease of use for the typical |
| * cases (flat schema or nested maps.) Enables construction of unions, |
| * union lists (AKA "list vector") repeated lists and combinations of |
| * the above structures. |
| * <dt>SchemaBuilder</dt> |
| * <dd>Drill normally writes data to vectors, then "discovers" the row set schema based on the |
| * data written. It is usually far easier to simply declare a schema, then |
| * read and write data according to that schema. The schema builder provides a simple, |
| * fluent tool to create a row set schema. That schema then drives the row set readers |
| * and writers, the row set printer and the row set comparison.</dd> |
| * </dl> |
| */ |
| |
| package org.apache.drill.exec.record.metadata; |
