In-memory Natual Join. More...

#include <jnatural.h>

Inheritance diagram for ibis::jNatural:

Public Member Functions
virtual int64_t	count () const
	Use sort-merge join. More...

template<typename T >
ibis::table *	fillResult (size_t nrows, const std::string &desc, const ibis::array_t< T > &rjcol, const ibis::table::typeArray &rtypes, const ibis::table::bufferArray &rbuff, const ibis::array_t< T > &sjcol, const ibis::table::typeArray &stypes, const ibis::table::bufferArray &sbuff, const ibis::table::stringArray &tcname, const std::vector< uint32_t > &tcnpos)
	Generate a table representing an equi-join in memory. More...

	jNatural (const ibis::part partr, const ibis::part parts, const char colname, const char condr, const char conds, const char sel)
	Constructor. More...

	jNatural (const ibis::part partr, const ibis::part parts, const ibis::column colr, const ibis::column cols, const ibis::qExpr condr, const ibis::qExpr conds, const ibis::selectClause sel, const ibis::fromClause frm, const char *desc)
	Constructor. More...

virtual void	roughCount (uint64_t &nmin, uint64_t &nmax) const
	Estimate the number of hits. Don't do much right now, may change later.

virtual ibis::table *	select () const
	Evaluate the select clause specified in the constructor.

virtual ibis::table *	select (const char *) const
	Produce a project based on the given select clause. More...

virtual ibis::table *	select (const ibis::table::stringArray &colnames) const
	Select values for a list of column names. More...

Static Protected Member Functions
template<typename T >
static table *	fillResult (size_t nrows, const std::string &desc, const ibis::array_t< T > &rjcol, const ibis::table::typeArray &rtypes, const ibis::table::bufferArray &rbuff, const ibis::array_t< T > &sjcol, const ibis::table::typeArray &stypes, const ibis::table::bufferArray &sbuff, const ibis::table::stringArray &cnamet, const std::vector< uint32_t > &cnpos)

static table *	fillResult (size_t nrows, const std::string &desc, const std::vector< std::string > &rjcol, const ibis::table::typeArray &rtypes, const ibis::table::bufferArray &rbuff, const std::vector< std::string > &sjcol, const ibis::table::typeArray &stypes, const ibis::table::bufferArray &sbuff, const ibis::table::stringArray &cnamet, const std::vector< uint32_t > &cnpos)
	Form the joined table for string valued join columns. More...

Protected Attributes
const ibis::column &	colR_

const ibis::column &	colS_

std::string	desc_

const ibis::fromClause *	frm_

ibis::bitvector	maskR_

ibis::bitvector	maskS_

int64_t	nrows

array_t< uint32_t > *	orderR_

array_t< uint32_t > *	orderS_

const ibis::part &	R_

const ibis::part &	S_

const ibis::selectClause *	sel_

void *	valR_

void *	valS_

Additional Inherited Members
Static Public Member Functions inherited from ibis::quaere
static quaere *	create (const char sel, const char from, const char *where)
	Create a query object using the global datasets.

static quaere *	create (const char sel, const char from, const char *where, const ibis::partList &prts)
	Generate a query expression. More...

static quaere *	create (const ibis::part partr, const ibis::part parts, const char colname, const char condr=0, const char conds=0, const char sel=0)
	Specify a natural join operation. More...

Protected Member Functions inherited from ibis::quaere
	quaere ()
	Default constructor. Only used by derived classes.

Detailed Description

In-memory Natual Join.

Warning: This is an experimental feature of FastBit. The current design is very limited and is likely to go through major revisions frequently. Feel free to express your opinions on the FastBit mailing list fastb.nosp@m.it-u.nosp@m.sers@.nosp@m.hpcr.nosp@m.dm.lb.nosp@m.l.go.nosp@m.v.

Constructor & Destructor Documentation

ibis::jNatural::jNatural	(	const ibis::part *	partr,
		const ibis::part *	parts,
		const char *	colname,
		const char *	condr,
		const char *	conds,
		const char *	sel
	)

Constructor.

This constructor handles a join equivalent to the following SQL statement

From partr Join parts Using(colname) Where condr And conds

Note that conditions specified in condr is for partr only, and conds is for parts only. When the column names in these conditions contain table names, the table names in them are ignored. If no conditions are specified, all valid records in the partition will participate in the natural join. This constructor avoids the need of specifying an alias when performing self-join, however, it also makes it impossible to distingush the column names in the select clause.

References ibis::bitvector::copy(), ibis::countQuery::evaluate(), ibis::countQuery::getHitVector(), ibis::column::getNullMask(), ibis::countQuery::getWhereClause(), ibis::part::name(), ibis::countQuery::setWhereClause(), ibis::column::type(), and ibis::TYPESTRING.

ibis::jNatural::jNatural	(	const ibis::part *	partr,
		const ibis::part *	parts,
		const ibis::column *	colr,
		const ibis::column *	cols,
		const ibis::qExpr *	condr,
		const ibis::qExpr *	conds,
		const ibis::selectClause *	sel,
		const ibis::fromClause *	frm,
		const char *	desc
	)

Constructor.

This constructor handles a join expression equivalent to one of the following SQL statements

From partr Join parts On colr = cols where condr and conds;

From partr, parts where partr.colr = parts.cols and condr and conds;

Note that this function processes the selection conditions on partr and parts immediately and therefore does not actually remember the conditions condr and conds. To preserve those conditions, it is recommended to keep the original query string as the description desc.

References ibis::bitvector::copy(), ibis::countQuery::evaluate(), ibis::countQuery::getHitVector(), ibis::column::getNullMask(), ibis::countQuery::getWhereClause(), ibis::part::name(), ibis::column::name(), and ibis::countQuery::setWhereClause().

Member Function Documentation

int64_t ibis::jNatural::count ( ) const

virtual

Use sort-merge join.

This function sorts the qualified values and counts the number of results.

Implements ibis::quaere.

References ibis::CATEGORY, ibis::DOUBLE, ibis::FLOAT, ibis::INT, ibis::LONG, ibis::SHORT, ibis::util::sortMerge(), ibis::TEXT, ibis::UBYTE, ibis::UINT, ibis::ULONG, and ibis::USHORT.

ibis::table * ibis::jNatural::fillResult	(	size_t	nrows,
		const std::string &	desc,
		const std::vector< std::string > &	rjcol,
		const ibis::table::typeArray &	rtypes,
		const ibis::table::bufferArray &	rbuff,
		const std::vector< std::string > &	sjcol,
		const ibis::table::typeArray &	stypes,
		const ibis::table::bufferArray &	sbuff,
		const ibis::table::stringArray &	tcname,
		const std::vector< uint32_t > &	tcnpos
	)

staticprotected

Form the joined table for string valued join columns.

The caller provides all relevant values, this function only needs to join them to produce the output data table.

References ibis::table::allocateBuffer(), ibis::bord::copyValue(), ibis::table::freeBuffers(), ibis::util::ref(), ibis::util::shortName(), ibis::array_t< T >::size(), and ibis::UNKNOWN_TYPE.

template<typename T >

ibis::table* ibis::jNatural::fillResult	(	size_t	nrows,
		const std::string &	desc,
		const ibis::array_t< T > &	rjcol,
		const ibis::table::typeArray &	rtypes,
		const ibis::table::bufferArray &	rbuff,
		const ibis::array_t< T > &	sjcol,
		const ibis::table::typeArray &	stypes,
		const ibis::table::bufferArray &	sbuff,
		const ibis::table::stringArray &	tcname,
		const std::vector< uint32_t > &	tcnpos
	)

Generate a table representing an equi-join in memory.

The input to this function are values to go into the resulting table. It only needs to match the rows and fill the output table.

References ibis::table::allocateBuffer(), ibis::bord::copyValue(), ibis::table::freeBuffers(), ibis::util::ref(), ibis::util::shortName(), ibis::array_t< T >::size(), and ibis::UNKNOWN_TYPE.

ibis::table * ibis::jNatural::select ( const char * ) const

virtual

Produce a project based on the given select clause.

The joint data table is defined by the where clause and the from clause given to the constructor of this object.

Implements ibis::quaere.

References ibis::selectClause::aggExpr(), ibis::selectClause::aggSize(), ibis::table::describe(), ibis::selectClause::getAggregator(), ibis::table::nColumns(), ibis::table::nRows(), ibis::array_t< T >::push_back(), ibis::math::barrel::recordVariable(), ibis::array_t< T >::reserve(), and ibis::util::shortName().

ibis::table * ibis::jNatural::select ( const ibis::table::stringArray & colnames ) const

virtual

Select values for a list of column names.

Note: The incoming argument MUST be a list of column names. Can not be any aggregation functions!

fill the in-memory buffer

Implements ibis::quaere.

References ibis::CATEGORY, ibis::DOUBLE, ibis::FLOAT, ibis::table::freeBuffers(), ibis::category::getDictionary(), ibis::bord::column::getDictionary(), ibis::INT, ibis::LONG, ibis::util::ref(), ibis::util::reorder(), ibis::bord::column::setDictionary(), ibis::SHORT, ibis::util::shortName(), ibis::array_t< T >::size(), ibis::TEXT, ibis::column::type(), ibis::TYPESTRING, ibis::UBYTE, ibis::UINT, ibis::ULONG, ibis::UNKNOWN_TYPE, and ibis::USHORT.

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

jnatural.h
jnatural.cpp



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Public Member Functions

Static Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation