ibis::sapid Class Reference

The multicomponent equality encoded index. More...

#include <irelic.h>

Inheritance diagram for ibis::sapid:

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 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.
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.
	sapid (const ibis::column *c=0, const char *f=0, const uint32_t nbase=2)
	Constructor.
	sapid (const ibis::column *c, ibis::fileManager::storage *st, size_t start=8)
	Reconstruct an index from the content of a storage object.
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 the index to the specified location.

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Detailed Description

The multicomponent equality encoded index.

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Constructor & Destructor Documentation

ibis::sapid::sapid	(	const ibis::column *	c = 0,
		const char *	f = 0,
		const uint32_t	nbase = 2
	)

Constructor.

If a bitmap index is present in the specified location, its header will be read into memory, otherwise a new bitmap index is created from current data.

References ibis::index::bits, ibis::fade::clear(), ibis::index::col, ibis::gVerbose, ibis::part::name(), ibis::column::name(), ibis::part::nRows(), ibis::index::nrows, print(), and ibis::array_t< T >::size().

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

Reconstruct an index from the content of a storage object.

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

    nrows(uint32_t)         -- the number of bits of a 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::index::bits, ibis::index::col, ibis::gVerbose, ibis::part::name(), ibis::column::name(), ibis::index::nrows, print(), and ibis::array_t< T >::size().

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Member Function Documentation

long ibis::sapid::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::fade.

References ibis::util::clear().

long ibis::sapid::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::fade.

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

virtual const char* ibis::sapid::name

(

)

const [inline, virtual]

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

Reimplemented from ibis::fade.

int ibis::sapid::write

(

const char *

dt

)

const [virtual]

Write the content of the index to the specified location.

The argument is the name of a directory or a file name. It is used by the function indexFileName to determine the actual index file name.

Reimplemented from ibis::fade.

References ibis::fileManager::flushFile(), ibis::gVerbose, ibis::fileManager::instance(), ibis::index::SAPID, UnixOpen, ibis::fade::write32(), and ibis::fade::write64().

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

• irelic.h
• isapid.cpp