cudf::hash_join Class Reference

Hash join that builds hash table in creation and probes results in subsequent *_join member functions. More...

#include <join.hpp>

Public Member Functions
	hash_join (hash_join const &)=delete
	hash_join (hash_join &&)=delete
hash_join &	operator= (hash_join const &)=delete
hash_join &	operator= (hash_join &&)=delete
	hash_join (cudf::table_view const &build, null_equality compare_nulls, rmm::cuda_stream_view stream=rmm::cuda_stream_default)
	Construct a hash join object for subsequent probe calls. More...
std::pair< std::unique_ptr< rmm::device_uvector< size_type > >, std::unique_ptr< rmm::device_uvector< size_type > > >	inner_join (cudf::table_view const &probe, null_equality compare_nulls=null_equality::EQUAL, rmm::cuda_stream_view stream=rmm::cuda_stream_default, rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource()) const
std::pair< std::unique_ptr< rmm::device_uvector< size_type > >, std::unique_ptr< rmm::device_uvector< size_type > > >	left_join (cudf::table_view const &probe, null_equality compare_nulls=null_equality::EQUAL, rmm::cuda_stream_view stream=rmm::cuda_stream_default, rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource()) const
std::pair< std::unique_ptr< rmm::device_uvector< size_type > >, std::unique_ptr< rmm::device_uvector< size_type > > >	full_join (cudf::table_view const &probe, null_equality compare_nulls=null_equality::EQUAL, rmm::cuda_stream_view stream=rmm::cuda_stream_default, rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource()) const

Detailed Description

Hash join that builds hash table in creation and probes results in subsequent *_join member functions.

This class enables the hash join scheme that builds hash table once, and probes as many times as needed (possibly in parallel).

Definition at line 500 of file join.hpp.

Constructor & Destructor Documentation

hash_join()

cudf::hash_join::hash_join	(	cudf::table_view const &	build,
		null_equality	compare_nulls,
		rmm::cuda_stream_view	stream = rmm::cuda_stream_default
	)

Construct a hash join object for subsequent probe calls.

Note

The hash_join object must not outlive the table viewed by build, else behavior is undefined.

Parameters

build	The build table, from which the hash table is built.
compare_nulls	Controls whether null join-key values should match or not.
stream	CUDA stream used for device memory operations and kernel launches

Member Function Documentation

full_join()

std::pair<std::unique_ptr<rmm::device_uvector<size_type> >, std::unique_ptr<rmm::device_uvector<size_type> > > cudf::hash_join::full_join	(	cudf::table_view const &	probe,
		null_equality	compare_nulls = null_equality::EQUAL,
		rmm::cuda_stream_view	stream = rmm::cuda_stream_default,
		rmm::mr::device_memory_resource *	mr = rmm::mr::get_current_device_resource()
	)		const

Returns the row indices that can be used to construct the result of performing a full join between two tables.

See also

cudf::full_join().

Parameters

probe	The probe table, from which the tuples are probed.
compare_nulls	Controls whether null join-key values should match or not.
mr	Device memory resource used to allocate the returned table and columns' device memory.
stream	CUDA stream used for device memory operations and kernel launches

Returns

A pair of columns [left_indices, right_indices] that can be used to construct the result of performing a full join between two tables with build and probe as the the join keys .

inner_join()

std::pair<std::unique_ptr<rmm::device_uvector<size_type> >, std::unique_ptr<rmm::device_uvector<size_type> > > cudf::hash_join::inner_join	(	cudf::table_view const &	probe,
		null_equality	compare_nulls = null_equality::EQUAL,
		rmm::cuda_stream_view	stream = rmm::cuda_stream_default,
		rmm::mr::device_memory_resource *	mr = rmm::mr::get_current_device_resource()
	)		const

Returns the row indices that can be used to construct the result of performing an inner join between two tables.

See also

cudf::inner_join().

Parameters

probe	The probe table, from which the tuples are probed.
compare_nulls	Controls whether null join-key values should match or not.
mr	Device memory resource used to allocate the returned table and columns' device memory.
stream	CUDA stream used for device memory operations and kernel launches

Returns

A pair of columns [left_indices, right_indices] that can be used to construct the result of performing an inner join between two tables with build and probe as the the join keys .

left_join()

std::pair<std::unique_ptr<rmm::device_uvector<size_type> >, std::unique_ptr<rmm::device_uvector<size_type> > > cudf::hash_join::left_join	(	cudf::table_view const &	probe,
		null_equality	compare_nulls = null_equality::EQUAL,
		rmm::cuda_stream_view	stream = rmm::cuda_stream_default,
		rmm::mr::device_memory_resource *	mr = rmm::mr::get_current_device_resource()
	)		const

Returns the row indices that can be used to construct the result of performing a left join between two tables.

See also

cudf::left_join().

Parameters

probe	The probe table, from which the tuples are probed.
compare_nulls	Controls whether null join-key values should match or not.
mr	Device memory resource used to allocate the returned table and columns' device memory.
stream	CUDA stream used for device memory operations and kernel launches

Returns

A pair of columns [left_indices, right_indices] that can be used to construct the result of performing a left join between two tables with build and probe as the the join keys .

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The documentation for this class was generated from the following file:

• join.hpp