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/*
 * Licensed to the Apache Software Foundation (ASF) under one
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 * 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
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/**
 * 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.
 * 
 * The classes include tools for reading and writing row sets, comparing
 * actual and expected results, and so on.
 * 

 * Drill defines a variety of record batch semantics, modeled here as
 * distinct row set classes:
 * 

 * RowSet
 * The abstract definition of a row set that defines operations available
 * on all row sets.
 * SingleRowSet (abstract)
 * Represents a row set that contains a single record batch (the typical
 * case.
 * DirectRowSet
 * A read-only single row set without a selection vector.
 * IndirectRowSet
 * A read-only, single row set with an SV2. Note that the SV2 itself is
 * writable (such as for sorting.)
 * ExtendableRowSet
 * 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.
 * HyperRowSet
 * A read-only row set made up of a collection of record batches, indexed via an SV4.
 * 
 * This package contains a number of helper classes:
 * 
 * {@link org.apache.drill.exec.physical.rowSet.RowSetWriter}
 * Writes data into an extendable row set.
 * {@link org.apache.drill.exec.physical.rowSet.RowSetReader}
 * Reads data from any but an extendable row set.
 * {@link org.apache.drill.exec.physical.rowSet.RowSetFormatter}
 * Prints a row set to stdout in a CSV-like form for easy debugging.
 * {@link org.apache.drill.exec.physical.rowSet.RowSetBuilder}
 * Creates and populates a row set in a fluent builder style.
 * 
 */
package org.apache.drill.exec.physical.rowSet;