ibis::fade Class Reference

The multicomponent range-encoded index. More...

#include <irelic.h>

Inheritance diagram for ibis::fade:

List of all members.

Public Member Functions
virtual long	append (const char *dt, const char *df, uint32_t nnew)
	Create an index based on data in df and append the result to the index in dt.
virtual void	binWeights (std::vector< uint32_t > &b) const
	Return the exact count for each distinct value.
virtual uint32_t	estimate (const ibis::qContinuousRange &expr) const
	Return the number of hits satisfying the given continuous range expression.
virtual double	estimateCost (const ibis::qContinuousRange &expr) const
	Estimate the cost of resolving the continuous range expression.
virtual long	evaluate (const ibis::qContinuousRange &expr, ibis::bitvector &hits) const
	Compute the hits as a bitvector.
virtual long	evaluate (const ibis::qDiscreteRange &expr, ibis::bitvector &hits) const
	Resolve a discrete range condition.
	fade (const ibis::column *c=0, const char *f=0, const uint32_t nbase=2)
	Construct a bitmap index from current data.
	fade (const ibis::column *c, ibis::fileManager::storage *st, size_t start=8)
	Reconstruct from content of fileManager::storage.
virtual double	getSum () const
	Compute the sum of all values of the column indexed.
virtual const char *	name () const
	Returns the name of the index, similar to the function type, but returns a string instead.
virtual void	print (std::ostream &out) const
	The printing function.
virtual int	read (const char *idxfile)
	Read the index contained in the file named f.
virtual int	read (ibis::fileManager::storage *st)
	Reconstruct an index from a piece of consecutive memory.
virtual long	select (const ibis::qContinuousRange &, void *) const
	Evaluate the range condition and select values.
virtual long	select (const ibis::qContinuousRange &, void *, ibis::bitvector &) const
	Evaluate the range condition, select values, and record the positions.
virtual void	speedTest (std::ostream &out) const
	A simple function to test the speed of the bitvector operations.
virtual INDEX_TYPE	type () const
	Returns an index type identifier.
virtual int	write (const char *dt) const
	Write the content of this index to a file.
Protected Member Functions
virtual void	clear ()
	Clear the existing content.
virtual size_t	getSerialSize () const throw ()
	Estiamte the size of the index in a file.
int	write32 (int fdes) const
	Write the content to a file already opened.
int	write64 (int fdes) const
	Write the content to a file already opened.
Protected Attributes
array_t< uint32_t >	bases
array_t< uint32_t >	cnts

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Detailed Description

The multicomponent range-encoded index.

Defined by Chan and Ioannidis (SIGMOD 98).

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Constructor & Destructor Documentation

ibis::fade::fade	(	const ibis::column *	c,
		ibis::fileManager::storage *	st,
		size_t	start = 8
	)

Reconstruct from content of fileManager::storage.

The content of the file (following the 8-byte header) is

• nrows(uint32_t) -- the number of bits in each bit sequence
• nobs (uint32_t) -- the number of bit sequences
• card (uint32_t) -- the number of distinct values, i.e., cardinality
• (padding to ensure the next data element is on 8-byte boundary)
• values (double[card]) -- the distinct values as doubles
• offset([nobs+1]) -- the starting positions of the bit sequences (as bit vectors)
• nbases(uint32_t) -- the number of components (bases) used
• cnts (uint32_t[card]) -- the counts for each distinct value
• bases(uint32_t[nbases])-- the bases sizes
• bitvectors -- the bitvectors one after another

References ibis::fileManager::storage::begin(), ibis::index::bits, ibis::index::col, ibis::index::FADE, ibis::gVerbose, ibis::part::name(), ibis::column::name(), ibis::index::nrows, print(), ibis::array_t< T >::size(), and ibis::array_t< T >::swap().

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Member Function Documentation

long ibis::fade::append	(	const char *	dt,
		const char *	df,
		uint32_t	nnew
	)		[virtual]

Create an index based on data in df and append the result to the index in dt.

Reimplemented from ibis::relic.

Reimplemented in ibis::sapid, and ibis::sbiad.

References ibis::util::clear().

void ibis::fade::clear

(

)

[protected, virtual]

Clear the existing content.

Free the objectes pointed to by the pointers.

Reimplemented from ibis::relic.

References ibis::util::clear().

Referenced by fade(), ibis::sapid::sapid(), and ibis::sbiad::sbiad().

uint32_t ibis::fade::estimate

(

const ibis::qContinuousRange &

expr

)

const [virtual]

Return the number of hits satisfying the given continuous range expression.

Reimplemented from ibis::relic.

double ibis::fade::estimateCost

(

const ibis::qContinuousRange &

expr

)

const [virtual]

Estimate the cost of resolving the continuous range expression.

The answer is in the number of bytes needed from this index.

Reimplemented from ibis::relic.

long ibis::fade::evaluate	(	const ibis::qDiscreteRange &	expr,
		ibis::bitvector &	answer
	)		const [virtual]

Resolve a discrete range condition.

The answer is a bitvector marking the rows satisfying the range conditions.

Reimplemented from ibis::relic.

Reimplemented in ibis::sapid, and ibis::sbiad.

References ibis::bitvector::cnt(), ibis::qDiscreteRange::getValues(), ibis::bitvector::set(), ibis::array_t< T >::size(), and ibis::bitvector::size().

virtual const char* ibis::fade::name

(

)

const [inline, virtual]

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

Reimplemented from ibis::relic.

Reimplemented in ibis::sapid, and ibis::sbiad.

int ibis::fade::write

(

const char *

dt

)

const [virtual]

Write the content of this index to a file.

The argument is the name of the directory or the index file name.

Reimplemented from ibis::relic.

Reimplemented in ibis::sapid, and ibis::sbiad.

References ibis::index::FADE, ibis::fileManager::flushFile(), ibis::gVerbose, ibis::fileManager::instance(), and UnixOpen.

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

• irelic.h
• ifade.cpp