com.gpudb

Class Type

java.lang.Object

com.gpudb.Type

All Implemented Interfaces:

Serializable

public final class Type
extends Object
implements Serializable

Immutable collection of metadata about a GPUdb type.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Type.Column Immutable collection of metadata about a column that is part of a GPUdb type.

Constructor Summary

Constructors

Constructor and Description
Type(List<Type.Column> columns) Creates a Type object with the specified column metadata and an empty type label.
Type(String typeSchema) Creates a Type object with column metadata from an Avro record schema and an empty type label.
Type(String label, List<Type.Column> columns) Creates a Type object with the specified metadata.
Type(String label, String typeSchema, Map<String,List<String>> properties) Creates a Type object with metadata in the format returned from the GPUdb /show/table or /show/types endpoints.
Type(String label, Type.Column... columns) Creates a Type object with the specified metadata.
Type(Type.Column... columns) Creates a Type object with the specified column metadata and an empty type label.

Method Summary

Methods

Modifier and Type	Method and Description
String	create(GPUdb gpudb) Creates a type in GPUdb based on the metadata in the Type object and returns the type ID for reference.
boolean	equals(Object obj)
static Type	fromTable(GPUdb gpudb, String tableName) Creates a Type object containing metadata for the GPUdb type of an existing table in GPUdb.
static Type	fromType(GPUdb gpudb, String typeId) Creates a Type object containing metadata for an existing type in GPUdb.
Type.Column	getColumn(int index) Gets the column with the specified index.
Type.Column	getColumn(String name) Gets the column with the specified name.
int	getColumnCount() Gets the number of columns.
int	getColumnIndex(String name) Gets the index of the column with the specified name.
List<Type.Column>	getColumns() Gets the list of columns that the type comprises.
String	getLabel() Gets the user-defined description string which can be used to differentiate between data with otherwise identical schemas.
org.apache.avro.Schema	getSchema() Gets the Avro record schema for the type.
int	hashCode()
Record	newInstance() Creates a new Record based on the type.
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Type

public Type(Type.Column... columns)

Creates a Type object with the specified column metadata and an empty type label.

Parameters:

columns - the list of columns that the type comprises

Throws:

IllegalArgumentException - if no columns are specified

Type

public Type(List<Type.Column> columns)

Creates a Type object with the specified column metadata and an empty type label.

Parameters:

columns - the list of columns that the type comprises

Throws:

IllegalArgumentException - if no columns are specified

Type

public Type(String label,
    Type.Column... columns)

Creates a Type object with the specified metadata.

Parameters:

label - a user-defined description string which can be used to differentiate between data with otherwise identical schemas

columns - the list of columns that the type comprises

Throws:

IllegalArgumentException - if no columns are specified

Type

public Type(String label,
    List<Type.Column> columns)

Creates a Type object with the specified metadata.

Parameters:

label - a user-defined description string which can be used to differentiate between data with otherwise identical schemas

columns - the list of columns that the type comprises

Throws:

IllegalArgumentException - if no columns are specified

Type

public Type(String typeSchema)

Creates a Type object with column metadata from an Avro record schema and an empty type label.

Parameters:

typeSchema - the Avro record schema for the type

Throws:

IllegalArgumentException - if typeSchema is invalid or contains unsupported field types

Type

public Type(String label,
    String typeSchema,
    Map<String,List<String>> properties)

Creates a Type object with metadata in the format returned from the GPUdb /show/table or /show/types endpoints.

Parameters:

label - a user-defined description string which can be used to differentiate between data with otherwise identical schemas

typeSchema - the Avro record schema for the type

properties - an optional map of column names to lists of properties that apply to those columns

Throws:

IllegalArgumentException - if typeSchema is invalid or contains unsupported field types, or if any properties are invalid

Method Detail

fromTable

public static Type fromTable(GPUdb gpudb,
             String tableName)
                      throws GPUdbException

Creates a Type object containing metadata for the GPUdb type of an existing table in GPUdb. Note that this method makes a request to GPUdb to obtain the metadata.

Parameters:

gpudb - the GPUdb instance from which to obtain the metadata

tableName - the name of the table in GPUdb

Returns:

the created Type object

Throws:

GPUdbException - if the table does not exist or is not homogeneous, or if an error occurs during the request for metadata

fromType

public static Type fromType(GPUdb gpudb,
            String typeId)
                     throws GPUdbException

Creates a Type object containing metadata for an existing type in GPUdb. Note that this method makes a request to GPUdb to obtain the metadata.

Parameters:

gpudb - the GPUdb instance from which to obtain the metadata

typeId - the type ID of the type in GPUdb

Returns:

the created Type object

Throws:

GPUdbException - if the type does not exist or if an error occurs during the request for metadata

getLabel

public String getLabel()

Gets the user-defined description string which can be used to differentiate between data with otherwise identical schemas.

Returns:

the label string

getColumns

public List<Type.Column> getColumns()

Gets the list of columns that the type comprises.

Returns:

the list of columns that the type comprises

getColumn

public Type.Column getColumn(int index)

Gets the column with the specified index.

Parameters:

index - the column index

Returns:

the column with the specified index

Throws:

IndexOutOfBoundsException - if the specified index is out of range

getColumn

public Type.Column getColumn(String name)

Gets the column with the specified name.

Parameters:

name - the column name

Returns:

the column with the specified name, or null if no such column exists

getColumnCount

public int getColumnCount()

Gets the number of columns.

Returns:

the number of columns

getColumnIndex

public int getColumnIndex(String name)

Gets the index of the column with the specified name.

Parameters:

name - the column name

Returns:

the index of the column with the specified name, or -1 if no such column exists

getSchema

public org.apache.avro.Schema getSchema()

Gets the Avro record schema for the type.

Returns:

the Avro record schema for the type

newInstance

public Record newInstance()

Creates a new Record based on the type.

Returns:

a new Record

create

public String create(GPUdb gpudb)
              throws GPUdbException

Creates a type in GPUdb based on the metadata in the Type object and returns the type ID for reference. If an identical type already exists in GPUdb, the type ID of the existing type will be returned and no new type will be created.

Parameters:

gpudb - the GPUdb instance in which to create the type

Returns:

the type ID of the type in GPUdb

Throws:

GPUdbException - if an error occurs while creating the type

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object