| /* |
| * 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 set of tools to work with row sets. |
| * A row set is a batch of Drill vectors, |
| * often called a "record batch." However, a record batch, in Drill, means |
| * not just the data, but also an operator on that data. The classes |
| * here work with the data itself, and can be used to test implementations |
| * of things such as code generated classes and so on. |
| * <p> |
| * The classes include tools for reading and writing row sets, comparing |
| * actual and expected results, and so on. |
| * <p> |
| * Drill defines a variety of record batch semantics, modeled here as |
| * distinct row set classes: |
| * <dl> |
| * <dt>RowSet</dt> |
| * <dd>The abstract definition of a row set that defines operations available |
| * on all row sets.</dd> |
| * <dt>SingleRowSet (abstract)</dt> |
| * <dd>Represents a row set that contains a single record batch (the typical |
| * case.</dd> |
| * <dt>DirectRowSet</dt> |
| * <dd>A read-only single row set without a selection vector.</dd> |
| * <dt>IndirectRowSet</dt> |
| * <dd>A read-only, single row set with an SV2. Note that the SV2 itself is |
| * writable (such as for sorting.)</dd> |
| * <dt>ExtendableRowSet</dt> |
| * <dd>A write-only, single row set used to create a new row set. Because of |
| * the way Drill sets row counts, an extendable row set cannot be read; instead |
| * at the completion of the write the extendable row set becomes a direct or |
| * indirect row set.</dd> |
| * <dt>HyperRowSet</dt> |
| * <dd>A read-only row set made up of a collection of record batches, indexed via an SV4.</dt> |
| * </dl> |
| * This package contains a number of helper classes: |
| * <dl> |
| * <dt>{@link org.apache.drill.exec.physical.rowSet.RowSetWriter}</dt> |
| * <dd>Writes data into an extendable row set.</dd> |
| * <dt>{@link org.apache.drill.exec.physical.rowSet.RowSetReader}</dt> |
| * <dd>Reads data from any but an extendable row set.</dd> |
| * <dt>{@link org.apache.drill.exec.physical.rowSet.RowSetFormatter}</dt> |
| * <dd>Prints a row set to stdout in a CSV-like form for easy debugging.</dd> |
| * <dt>{@link org.apache.drill.exec.physical.rowSet.RowSetBuilder}</dt> |
| * <dd>Creates and populates a row set in a fluent builder style.</dd> |
| * </dl> |
| */ |
| package org.apache.drill.exec.physical.rowSet; |
