ibis::pale Class Reference

A two-level index. More...

#include <ibin.h>

Inheritance diagram for ibis::pale:

List of all members.

Public Member Functions
virtual void	adjustLength (uint32_t nrows)
long	append (const ibis::pale &tail)
virtual long	append (const char *dt, const char *df, uint32_t nnew)
	Extend the index.
virtual void	binBoundaries (std::vector< double > &) const
	The function binBoundaries and binWeights return bin boundaries and counts of each bin respectively.
virtual void	binWeights (std::vector< uint32_t > &) const
virtual void	estimate (const ibis::qContinuousRange &expr, ibis::bitvector &lower, ibis::bitvector &upper) const
	Computes an approximation of hits as a pair of lower and upper bounds.
virtual long	evaluate (const ibis::qContinuousRange &expr, ibis::bitvector &hits) const
	To evaluate the exact hits.
virtual const char *	name () const
	Returns the name of the index, similar to the function type, but returns a string instead.
virtual uint32_t	numBins () const
	pale (const ibis::bin &rhs)
	pale (const ibis::column *c, ibis::fileManager::storage *st, uint32_t offset=8)
virtual void	print (std::ostream &out) const
	Prints human readable information.
virtual int	read (ibis::fileManager::storage *st)
	Reconstructs an index from an array of bytes.
virtual int	read (const char *idxfile)
	Reconstructs an index from the named file.
virtual void	speedTest (std::ostream &out) const
	Time some logical operations and print out their speed.
virtual INDEX_TYPE	type () const
	Returns an index type identifier.
virtual float	undecidable (const ibis::qContinuousRange &expr, ibis::bitvector &iffy) const
	Mark the position of the rows that can not be decided with this index.
virtual int	write (const char *dt) const
	Save index to a file.
Protected Member Functions
virtual void	clear ()
	Clear the existing content.

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Detailed Description

A two-level index.

Coarse level not cumulative, fine level is cumulative.

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Member Function Documentation

void ibis::pale::binBoundaries

(

std::vector< double > &

)

const [virtual]

The function binBoundaries and binWeights return bin boundaries and counts of each bin respectively.

Reimplemented from ibis::bin.

References ibis::bin::bounds.

void ibis::pale::clear

(

)

[protected, virtual]

Clear the existing content.

Free the objectes pointed to by the pointers.

Reimplemented from ibis::bin.

References ibis::bin::clear().

Referenced by read().

void ibis::pale::estimate	(	const ibis::qContinuousRange &	expr,
		ibis::bitvector &	lower,
		ibis::bitvector &	upper
	)			const [virtual]

Computes an approximation of hits as a pair of lower and upper bounds.

Parameters:

	expr	the query expression to be evaluated.
	lower	a bitvector marking a subset of the hits. All rows marked with one (1) are definitely hits.
	upper	a bitvector marking a superset of the hits. All hits are marked with one, but some of the rows marked one may not be hits. If the variable upper is empty, the variable lower is assumed to contain the exact answer.

Reimplemented from ibis::bin.

References ibis::index::activate(), ibis::index::bits, ibis::bin::bounds, ibis::bitvector::clear(), ibis::index::col, ibis::bitvector::copy(), ibis::gVerbose, ibis::qContinuousRange::leftBound(), ibis::qContinuousRange::leftOperator(), ibis::column::logWarning(), ibis::bin::maxval, ibis::bin::minval, ibis::qContinuousRange::rightBound(), ibis::qContinuousRange::rightOperator(), ibis::bitvector::set(), and ibis::index::sumBins().

Referenced by evaluate(), and undecidable().

long ibis::pale::evaluate	(	const ibis::qContinuousRange &	expr,
		ibis::bitvector &	hits
	)			const [virtual]

To evaluate the exact hits.

On success, return the number of hits, otherwise a negative value is returned.

Reimplemented from ibis::bin.

References ibis::bitvector::cnt(), ibis::index::col, ibis::part::doScan(), estimate(), ibis::column::partition(), and ibis::bitvector::size().

virtual const char* ibis::pale::name

(

)

const [inline, virtual]

Returns the name of the index, similar to the function type, but returns a string instead.

Reimplemented from ibis::bin.

Referenced by read().

void ibis::pale::print

(

std::ostream &

out

)

const [virtual]

Prints human readable information.

Outputs information about the index as text to the specified output stream.

Reimplemented from ibis::bin.

References ibis::index::bits, ibis::bin::bounds, ibis::index::col, ibis::gVerbose, ibis::bin::maxval, ibis::bin::minval, ibis::column::name(), ibis::part::name(), and ibis::column::partition().

int ibis::pale::read

(

ibis::fileManager::storage *

st

)

[virtual]

Reconstructs an index from an array of bytes.

Intended for internal use only!

Reimplemented from ibis::bin.

References ibis::fileManager::storage::begin(), ibis::util::logger::buffer(), clear(), ibis::index::col, ibis::fileManager::storage::filename(), ibis::gVerbose, ibis::bin::read(), and ibis::fileManager::storage::unnamed().

int ibis::pale::read

(

const char *

name

)

[virtual]

Reconstructs an index from the named file.

The name can be the directory containing an index file. In this case, the name of the index file must be the name of the column followed by ".idx" suffix.

Reimplemented from ibis::bin.

References ibis::index::bits, ibis::bin::bounds, ibis::util::logger::buffer(), clear(), ibis::index::col, ibis::index::fname, ibis::gVerbose, ibis::index::indexFileName(), ibis::fileManager::instance(), ibis::column::logMessage(), ibis::column::logWarning(), ibis::bin::maxval, ibis::bin::minval, name(), ibis::index::nrows, ibis::index::offsets, ibis::fileManager::pageSize(), ibis::index::PALE, ibis::fileManager::recordPages(), ibis::bitvector::setSize(), ibis::bitvector::size(), and array_t< T >::swap().

float ibis::pale::undecidable	(	const ibis::qContinuousRange &	expr,
		ibis::bitvector &	iffy
	)			const [virtual]

Mark the position of the rows that can not be decided with this index.

Parameters:

	expr	the range conditions to be evaluated.
	iffy	the bitvector marking the positions of rows that can not be decided using the index. Return value is the expected fraction of undecided rows that might satisfy the range conditions.

Reimplemented from ibis::bin.

References ibis::bitvector::cnt(), estimate(), ibis::qContinuousRange::leftBound(), ibis::bin::maxval, ibis::bin::minval, ibis::qContinuousRange::rightBound(), ibis::bitvector::set(), and ibis::bitvector::size().

int ibis::pale::write

(

const char *

name

)

const [virtual]

Save index to a file.

Outputs the index in a compact binary format to the named file or directory. The index file contains a header that can be identified by the function isIndex.

Reimplemented from ibis::bin.

References ibis::index::col, ibis::index::fname, ibis::gVerbose, ibis::index::indexFileName(), ibis::column::logWarning(), ibis::column::name(), ibis::part::name(), ibis::index::PALE, and ibis::column::partition().

Referenced by append().

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

• ibin.h
• ixpale.cpp