VectorSchemaRoot (Arrow Vectors 6.0.1 API)

java.lang.Object
- org.apache.arrow.vector.VectorSchemaRoot

すべての実装されたインタフェース:

AutoCloseable
```
public class VectorSchemaRoot
extends Object
implements AutoCloseable
```
Holder for a set of vectors to be loaded/unloaded. A VectorSchemaRoot is a container that can hold batches, batches flow through VectorSchemaRoot as part of a pipeline. Note this is different from other implementations (i.e. in C++ and Python, a RecordBatch is a collection of equal-length vector instances and was created each time for a new batch). The recommended usage for VectorSchemaRoot is creating a single VectorSchemaRoot based on the known schema and populated data over and over into the same VectorSchemaRoot in a stream of batches rather than create a new VectorSchemaRoot instance each time (see Flight or ArrowFileWriter for better understanding). Thus at any one point a VectorSchemaRoot may have data or may have no data (say it was transferred downstream or not yet populated).

コンストラクタのサマリー

コンストラクタ
コンストラクタと説明
`VectorSchemaRoot(FieldVector parent)` Constructs a new instance containing the children of parent but not the parent itself.
`VectorSchemaRoot(Iterable<FieldVector> vectors)` Constructs new instance containing each of the vectors.
`VectorSchemaRoot(List<Field> fields, List<FieldVector> fieldVectors)` Constructs a new instance.
`VectorSchemaRoot(List<Field> fields, List<FieldVector> fieldVectors, int rowCount)` Constructs a new instance.
`VectorSchemaRoot(Schema schema, List<FieldVector> fieldVectors, int rowCount)` Constructs a new instance.

メソッドのサマリー

すべてのメソッド staticメソッドインスタンス・メソッド concreteメソッド
修飾子とタイプ	メソッドと説明
`VectorSchemaRoot`	`addVector(int index, FieldVector vector)` Add vector to the record batch, producing a new VectorSchemaRoot.
`void`	`allocateNew()` Do an adaptive allocation of each vector for memory purposes.
`boolean`	`approxEquals(VectorSchemaRoot other)` Determine if two VectorSchemaRoots are approximately equal using default functions to calculate difference between float/double values.
`boolean`	`approxEquals(VectorSchemaRoot other, VectorValueEqualizer<Float4Vector> floatDiffFunction, VectorValueEqualizer<Float8Vector> doubleDiffFunction)` Determine if two VectorSchemaRoots are approximately equal using the given functions to calculate difference between float/double values.
`void`	`clear()` Release all the memory for each vector held in this root.
`void`	`close()`
`String`	`contentToTSVString()` Returns a tab separated value of vectors (based on their java object representation).
`static VectorSchemaRoot`	`create(Schema schema, BufferAllocator allocator)` Creates a new set of empty vectors corresponding to the given schema.
`boolean`	`equals(VectorSchemaRoot other)` Determine if two VectorSchemaRoots are exactly equal.
`List<FieldVector>`	`getFieldVectors()`
`int`	`getRowCount()`
`Schema`	`getSchema()`
`FieldVector`	`getVector(Field field)`
`FieldVector`	`getVector(int index)`
`FieldVector`	`getVector(String name)` gets a vector by name.
`static VectorSchemaRoot`	`of(FieldVector... vectors)` Constructs a new instance from vectors.
`VectorSchemaRoot`	`removeVector(int index)` Remove vector from the record batch, producing a new VectorSchemaRoot.
`void`	`setRowCount(int rowCount)` Set the row count of all the vectors in this container.
`VectorSchemaRoot`	`slice(int index)` Slice this root from desired index.
`VectorSchemaRoot`	`slice(int index, int length)` Slice this root at desired index and length.
`boolean`	`syncSchema()` Synchronizes the schema from the current vectors.

クラスから継承されたメソッド java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- コンストラクタの詳細
  - VectorSchemaRoot
```
public VectorSchemaRoot(Iterable<FieldVector> vectors)
```
    Constructs new instance containing each of the vectors.
  - VectorSchemaRoot
```
public VectorSchemaRoot(FieldVector parent)
```
    Constructs a new instance containing the children of parent but not the parent itself.
  - VectorSchemaRoot
```
public VectorSchemaRoot(List<Field> fields,
                        List<FieldVector> fieldVectors)
```
    Constructs a new instance.
    
    パラメータ:
    
    fields - The types of each vector.
    
    fieldVectors - The data vectors (must be equal in size to fields.
  - VectorSchemaRoot
```
public VectorSchemaRoot(List<Field> fields,
                        List<FieldVector> fieldVectors,
                        int rowCount)
```
    Constructs a new instance.
    
    パラメータ:
    
    fields - The types of each vector.
    
    fieldVectors - The data vectors (must be equal in size to fields.
    
    rowCount - The number of rows contained.
  - VectorSchemaRoot
```
public VectorSchemaRoot(Schema schema,
                        List<FieldVector> fieldVectors,
                        int rowCount)
```
    Constructs a new instance.
    
    パラメータ:
    
    schema - The schema for the vectors.
    
    fieldVectors - The data vectors.
    
    rowCount - The number of rows
- メソッドの詳細
  - create
```
public static VectorSchemaRoot create(Schema schema,
                                      BufferAllocator allocator)
```
    Creates a new set of empty vectors corresponding to the given schema.
  - of
```
public static VectorSchemaRoot of(FieldVector... vectors)
```
    Constructs a new instance from vectors.
  - allocateNew
```
public void allocateNew()
```
    Do an adaptive allocation of each vector for memory purposes. Sizes will be based on previously defined initial allocation for each vector (and subsequent size learned).
  - clear
```
public void clear()
```
    Release all the memory for each vector held in this root. This DOES NOT remove vectors from the container.
  - getFieldVectors
```
public List<FieldVector> getFieldVectors()
```
  - getVector
```
public FieldVector getVector(String name)
```
    gets a vector by name. if name occurs multiple times this returns the first inserted entry for name
  - getVector
```
public FieldVector getVector(Field field)
```
  - getVector
```
public FieldVector getVector(int index)
```
  - addVector
```
public VectorSchemaRoot addVector(int index,
                                  FieldVector vector)
```
    Add vector to the record batch, producing a new VectorSchemaRoot.
    
    パラメータ:
    
    index - field index
    
    vector - vector to be added.
    
    戻り値:
    
    out VectorSchemaRoot with vector added
  - removeVector
```
public VectorSchemaRoot removeVector(int index)
```
    Remove vector from the record batch, producing a new VectorSchemaRoot.
    
    パラメータ:
    
    index - field index
    
    戻り値:
    
    out VectorSchemaRoot with vector removed
  - getSchema
```
public Schema getSchema()
```
  - getRowCount
```
public int getRowCount()
```
  - setRowCount
```
public void setRowCount(int rowCount)
```
    Set the row count of all the vectors in this container. Also sets the value count for each root level contained FieldVector.
    
    パラメータ:
    
    rowCount - Number of records.
  - close
```
public void close()
```
    定義:
    
    close インタフェース内 AutoCloseable
  - contentToTSVString
```
public String contentToTSVString()
```
    Returns a tab separated value of vectors (based on their java object representation).
  - syncSchema
```
public boolean syncSchema()
```
    Synchronizes the schema from the current vectors. In some cases, the schema and the actual vector structure may be different. This can be caused by a promoted writer (For details, please see PromotableWriter). For example, when writing different types of data to a ListVector may lead to such a case. When this happens, this method should be called to bring the schema and vector structure in a synchronized state.
    
    戻り値:
    
    true if the schema is updated, false otherwise.
  - slice
```
public VectorSchemaRoot slice(int index)
```
    Slice this root from desired index.
    
    パラメータ:
    
    index - start position of the slice
    
    戻り値:
    
    the sliced root
  - slice
```
public VectorSchemaRoot slice(int index,
                              int length)
```
    Slice this root at desired index and length.
    
    パラメータ:
    
    index - start position of the slice
    
    length - length of the slice
    
    戻り値:
    
    the sliced root
  - equals
```
public boolean equals(VectorSchemaRoot other)
```
    Determine if two VectorSchemaRoots are exactly equal.
  - approxEquals
```
public boolean approxEquals(VectorSchemaRoot other,
                            VectorValueEqualizer<Float4Vector> floatDiffFunction,
                            VectorValueEqualizer<Float8Vector> doubleDiffFunction)
```
    Determine if two VectorSchemaRoots are approximately equal using the given functions to calculate difference between float/double values. Note that approx equals are in regards to floating point values, other values are comparing to exactly equals.
    
    パラメータ:
    
    floatDiffFunction - function to calculate difference between float values.
    
    doubleDiffFunction - function to calculate difference between double values.
  - approxEquals
```
public boolean approxEquals(VectorSchemaRoot other)
```
    Determine if two VectorSchemaRoots are approximately equal using default functions to calculate difference between float/double values.

クラス VectorSchemaRoot

コンストラクタのサマリー

メソッドのサマリー

クラスから継承されたメソッド java.lang.Object

コンストラクタの詳細

VectorSchemaRoot

VectorSchemaRoot

VectorSchemaRoot

VectorSchemaRoot

VectorSchemaRoot

メソッドの詳細

create

of

allocateNew

clear

getFieldVectors

getVector

getVector

getVector

addVector

removeVector

getSchema

getRowCount

setRowCount

close

contentToTSVString

syncSchema

slice

slice

equals

approxEquals

approxEquals