Vertica::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 Vertica::TransformFunction:

Collaboration diagram for Vertica::TransformFunction:

Public Member Functions
virtual void	cancel (ServerInterface &srvInterface)
virtual void	destroy (ServerInterface &srvInterface, const SizedColumnTypes &argTypes)
virtual void	destroy (ServerInterface &srvInterface, const SizedColumnTypes &argTypes, SessionParamWriterMap &udSessionParams)
bool	isCanceled ()
virtual void	processPartition (ServerInterface &srvInterface, PartitionReader &input_reader, PartitionWriter &output_writer)=0
virtual void	setup (ServerInterface &srvInterface, const SizedColumnTypes &argTypes)

Protected Attributes
volatile bool	canceled

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

virtual void Vertica::UDXObjectCancelable::cancel ( ServerInterface &  srvInterface )

inlinevirtualinherited

This function is invoked from a different thread when the execution is canceled This baseclass cancel should be called in any override.

virtual void Vertica::UDXObject::destroy ( ServerInterface &  srvInterface, const SizedColumnTypes &  argTypes  )

inlinevirtualinherited

Perform per instance destruction. This function may throw errors

virtual void Vertica::UDXObject::destroy ( ServerInterface &  srvInterface, const SizedColumnTypes &  argTypes, SessionParamWriterMap &  udSessionParams  )

inlinevirtualinherited

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

bool Vertica::UDXObjectCancelable::isCanceled ( )

inlineinherited

Returns true if execution was canceled.

virtual void Vertica::TransformFunction::processPartition ( ServerInterface &  srvInterface, PartitionReader &  input_reader, PartitionWriter &  output_writer  )

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

virtual void Vertica::UDXObject::setup ( ServerInterface &  srvInterface, const SizedColumnTypes &  argTypes  )

inlinevirtualinherited

Perform per instance initialization. This function may throw errors.