Functions for selectivity estimation of span types. More...

#include "pg_temporal/span_selfuncs.h"
#include <assert.h>
#include <access/htup_details.h>
#include "utils/syscache.h"
#include <utils/lsyscache.h>
#include <catalog/pg_statistic.h>
#include <meos.h>
#include <meos_internal.h>
#include "temporal/set.h"
#include "temporal/span.h"
#include "pg_temporal/meos_catalog.h"
#include "pg_temporal/span_analyze.h"
#include "pg_temporal/temporal_selfuncs.h"

Functions
Datum	_mobdb_span_joinsel (PG_FUNCTION_ARGS)
	Utility function to read the calculated selectivity for a given couple of table/column, and operator. More...

Datum	_mobdb_span_sel (PG_FUNCTION_ARGS)
	Utility function to read the calculated selectivity for a given table/column, operator, and search span. More...

double	calc_length_hist_frac (Datum *hist_length, int hist_length_nvalues, double length1, double length2, bool equal)
	Calculate the average of function P(x), in the interval [length1, length2], where P(x) is the fraction of tuples with length < x (or length <= x if 'equal' is true) More...

double	get_len_position (double value, double hist1, double hist2)
	Get relative position of a value in a length histogram bin in a [0,1] range. More...

int	length_hist_bsearch (Datum *hist_length, int hist_length_nvalues, double value, bool equal)
	Binary search on length histogram. More...

static int	span_bound_bsearch (const SpanBound value, const SpanBound hist, int hist_nvalues, bool equal)
	Binary search on an array of span bounds. More...

static float8	span_bound_distance (const SpanBound bound1, const SpanBound bound2)
	Measure distance between two span bounds. More...

void	span_const_to_span (Node other, Span span)
	Transform the constant into a span. More...

Datum	Span_joinsel (PG_FUNCTION_ARGS)
	Join selectivity for spans. More...

Selectivity	span_joinsel (PlannerInfo root, bool value, meosOper oper, List args, JoinType jointype UNUSED, SpecialJoinInfo *sjinfo)
	Estimate join selectivity for spans. More...

float8	span_joinsel_default (meosOper oper UNUSED)
	Return a default join selectivity estimate for given operator, when we don't have statistics or cannot use them for some reason. More...

static Selectivity	span_joinsel_hist (VariableStatData vardata1, VariableStatData vardata2, bool value, meosOper oper)
	Calculate span operator selectivity using histograms of span bounds. More...

static Selectivity	span_joinsel_hist1 (AttStatsSlot hslot1, AttStatsSlot hslot2, AttStatsSlot *lslot, meosOper oper)
	Calculate span operator selectivity using histograms of span bounds. More...

static Selectivity	span_joinsel_oper (SpanBound lower1, SpanBound upper1, int nhist1, SpanBound lower2, SpanBound upper2, int nhist2, Datum *length, int length_nvalues, meosOper oper)
	Look up the fraction of values in the first histogram that satisfy an operator with respect to a value in the second histogram. More...

static Selectivity	span_joinsel_scalar (const SpanBound hist1, int nhist1, const SpanBound hist2, int nhist2, bool equal UNUSED)

static float8	span_position (const SpanBound value, const SpanBound hist1, const SpanBound *hist2)
	Get relative position of value in histogram bin in [0,1] span. More...

Datum	Span_sel (PG_FUNCTION_ARGS)
	Restriction selectivity for span operators. More...

Selectivity	span_sel (PlannerInfo root, Oid operid, List args, int varRelid)
	Restriction selectivity for span operators. More...

static double	span_sel_contained (SpanBound const_lower, SpanBound const_upper, SpanBound hist_lower, int hist_nvalues, Datum hist_length, int hist_length_nvalues)
	Calculate selectivity of "var <@ const" operator, i.e., estimate the fraction of spans that fall within the constant lower and upper bounds. More...

static double	span_sel_contains (SpanBound const_lower, SpanBound const_upper, SpanBound hist_lower, int hist_nvalues, Datum hist_length, int hist_length_nvalues)
	Calculate selectivity of "var @> const" operator, i.e., estimate the fraction of spans that contain the constant lower and upper bounds. More...

float8	span_sel_default (meosOper oper UNUSED)
	Return a default selectivity estimate for given operator, when we don't have statistics or cannot use them for some reason. More...

Selectivity	span_sel_hist (VariableStatData vardata, const Span constval, meosOper oper, bool value)
	Calculate span operator selectivity using histograms of span bounds. More...

static Selectivity	span_sel_hist1 (AttStatsSlot hslot, AttStatsSlot lslot, const Span *constval, meosOper oper)
	Calculate span operator selectivity using histograms of span bounds. More...

static Selectivity	span_sel_overlaps (const SpanBound const_lower, const SpanBound const_upper, const SpanBound hist_lower, const SpanBound hist_upper, int nhist)
	Calculate the selectivity of "var && const" operator, i.e., estimate the fraction of spans that overlap the constant lower and upper bounds using the histograms of span lower and upper bounds. More...

static Selectivity	span_sel_scalar (const SpanBound constbound, const SpanBound hist, int nhist, bool equal)
	Estimate the fraction of values less than (or equal to, if 'equal' argument is true) a given const in a histogram of span bounds. More...

bool	time_oper_sel (meosOper oper UNUSED, meosType ltype, meosType rtype)
	Determine whether we can estimate selectivity for the operator. More...

static bool	value_oper_sel (Oid operid UNUSED, meosType ltype, meosType rtype)
	Determine whether we can estimate selectivity for the operator. More...

Detailed Description

Functions for selectivity estimation of span types.

These functions are based on those of the file rangetypes_selfuncs.c. Estimates are based on histograms of lower and upper bounds.