com.vertica.sdk.TransformFunction Class Reference

Interface for User-Defined Transform Function (UDTF). A UDTF operates on a table segment and returns zero or more rows of data. More...

Inheritance diagram for com.vertica.sdk.TransformFunction:

Collaboration diagram for com.vertica.sdk.TransformFunction:

Public Member Functions
final void	cancelUDX (ServerInterface srvInterface)
void	destroy (ServerInterface srvInterface, SizedColumnTypes argTypes)
void	destroy (ServerInterface srvInterface, SizedColumnTypes argTypes, SessionParamWriterMap udSessionParams)
boolean	isCanceled ()
abstract void	processPartition (ServerInterface srvInterface, PartitionReader input_reader, PartitionWriter input_writer) throws UdfException, DestroyInvocation
void	setup (ServerInterface srvInterface, SizedColumnTypes argTypes)

Protected Member Functions
void	cancel (ServerInterface srvInterface)

Detailed Description

Interface for User-Defined Transform Function (UDTF). A UDTF operates on a table segment and returns zero or more rows of data.

UDTFs can only be used in the SELECT list of a query. UDTFs are cancelable.

A TransformFunction must have an associated TransformFunctionFactory.

Member Function Documentation

void com.vertica.sdk.UDXObject.cancel ( ServerInterface  srvInterface )

protectedinherited

Cancel callback to be overridden by the UDX implementation. Called when the query running the UDX has been canceled.

Note

• This method will be invoked at most once per UDX object. Once a UDX object has been canceled, it will never be un-canceled.

• This method may be called from a separate thread, concurrently with other methods of this UDX object (but never the constructor). Implementations must be thread-safe with all methods of this UDX.

• This method will be invoked for either an explicit user cancel, or in the event of an error during query execution.

Referenced by com.vertica.sdk.UDXObject.cancelUDX().

final void com.vertica.sdk.UDXObject.cancelUDX ( ServerInterface  srvInterface )

inherited

Cancel callback invoked when the query running the UDX has been canceled.

See cancel().

void com.vertica.sdk.UDXFunction.destroy ( ServerInterface  srvInterface, SizedColumnTypes  argTypes  )

inherited

Perform per instance destruction. This function may throw errors

Referenced by com.vertica.sdk.UDXFunction.destroy().

void com.vertica.sdk.UDXFunction.destroy ( ServerInterface  srvInterface, SizedColumnTypes  argTypes, SessionParamWriterMap  udSessionParams  )

inherited

Perform per instance destruction and write session parameters to be used by UDxs that are invoked after this one returns. This function may throw errors

boolean com.vertica.sdk.UDXObject.isCanceled ( )

inherited

Returns true if execution was canceled.

Referenced by com.vertica.sdk.UDXObject.cancelUDX().

abstract void com.vertica.sdk.TransformFunction.processPartition ( ServerInterface  srvInterface, PartitionReader  input_reader, PartitionWriter  input_writer  ) throws UdfException, DestroyInvocation

pure virtual

Invoke a user defined transform on a set of rows. As the name suggests, a batch of rows are passed in for every invocation to amortize performance.

Parameters

srvInterface	a ServerInterface object used to communicate with Vertica
input_reader	input rows
output_writer	output location

void com.vertica.sdk.UDXFunction.setup ( ServerInterface  srvInterface, SizedColumnTypes  argTypes  )

inherited

Perform per instance initialization. This function may throw errors.