/*
* arraycontsel -- restriction selectivity for array @>, &&, <@ operators
*/
Datum
arraycontsel(PG_FUNCTION_ARGS)
{
PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
Oid operator = PG_GETARG_OID(1);
List *args = (List *) PG_GETARG_POINTER(2);
int varRelid = PG_GETARG_INT32(3);
VariableStatData vardata;
Node *other;
bool varonleft;
Selectivity selec;
Oid element_typeid;
/*
* If expression is not (variable op something) or (something op
* variable), then punt and return a default estimate.
*/
if (!get_restriction_variable(root, args, varRelid,
&vardata, &other, &varonleft))
PG_RETURN_FLOAT8(DEFAULT_SEL(operator));
/*
* Can't do anything useful if the something is not a constant, either.
*/
if (!IsA(other, Const))
{
ReleaseVariableStats(vardata);
PG_RETURN_FLOAT8(DEFAULT_SEL(operator));
}
/*
* The "&&", "@>" and "<@" operators are strict, so we can cope with a
* NULL constant right away.
*/
if (((Const *) other)->constisnull)
{
ReleaseVariableStats(vardata);
PG_RETURN_FLOAT8(0.0);
}
/*
* If var is on the right, commute the operator, so that we can assume the
* var is on the left in what follows.
*/
if (!varonleft)
{
if (operator == OID_ARRAY_CONTAINS_OP)
operator = OID_ARRAY_CONTAINED_OP;
else if (operator == OID_ARRAY_CONTAINED_OP)
operator = OID_ARRAY_CONTAINS_OP;
}
/*
* OK, there's a Var and a Const we're dealing with here. We need the
* Const to be an array with same element type as column, else we can't do
* anything useful. (Such cases will likely fail at runtime, but here
* we'd rather just return a default estimate.)
*/
element_typeid = get_base_element_type(((Const *) other)->consttype);
if (element_typeid != InvalidOid &&
element_typeid == get_base_element_type(vardata.vartype))
{
selec = calc_arraycontsel(&vardata, ((Const *) other)->constvalue,
element_typeid, operator);
}
else
{
selec = DEFAULT_SEL(operator);
}
ReleaseVariableStats(vardata);
CLAMP_PROBABILITY(selec);
PG_RETURN_FLOAT8((float8) selec);
}
/*
* ltreeparentsel - Selectivity of parent relationship for ltree data types.
*/
Datum
ltreeparentsel(PG_FUNCTION_ARGS)
{
PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
Oid operator = PG_GETARG_OID(1);
List *args = (List *) PG_GETARG_POINTER(2);
int varRelid = PG_GETARG_INT32(3);
VariableStatData vardata;
Node *other;
bool varonleft;
double selec;
/*
* If expression is not variable <@ something or something <@ variable,
* then punt and return a default estimate.
*/
if (!get_restriction_variable(root, args, varRelid,
&vardata, &other, &varonleft))
PG_RETURN_FLOAT8(DEFAULT_PARENT_SEL);
/*
* If the something is a NULL constant, assume operator is strict and
* return zero, ie, operator will never return TRUE.
*/
if (IsA(other, Const) &&
((Const *) other)->constisnull)
{
ReleaseVariableStats(vardata);
PG_RETURN_FLOAT8(0.0);
}
if (IsA(other, Const))
{
/* Variable is being compared to a known non-null constant */
Datum constval = ((Const *) other)->constvalue;
FmgrInfo contproc;
double mcvsum;
double mcvsel;
double nullfrac;
int hist_size;
fmgr_info(get_opcode(operator), &contproc);
/*
* Is the constant "<@" to any of the column's most common values?
*/
mcvsel = mcv_selectivity(&vardata, &contproc, constval, varonleft,
&mcvsum);
/*
* If the histogram is large enough, see what fraction of it the
* constant is "<@" to, and assume that's representative of the
* non-MCV population. Otherwise use the default selectivity for the
* non-MCV population.
*/
selec = histogram_selectivity(&vardata, &contproc,
constval, varonleft,
10, 1, &hist_size);
if (selec < 0)
{
/* Nope, fall back on default */
selec = DEFAULT_PARENT_SEL;
}
else if (hist_size < 100)
{
/*
* For histogram sizes from 10 to 100, we combine the histogram
* and default selectivities, putting increasingly more trust in
* the histogram for larger sizes.
*/
double hist_weight = hist_size / 100.0;
selec = selec * hist_weight +
DEFAULT_PARENT_SEL * (1.0 - hist_weight);
}
/* In any case, don't believe extremely small or large estimates. */
if (selec < 0.0001)
selec = 0.0001;
else if (selec > 0.9999)
selec = 0.9999;
if (HeapTupleIsValid(vardata.statsTuple))
nullfrac = ((Form_pg_statistic) GETSTRUCT(vardata.statsTuple))->stanullfrac;
else
nullfrac = 0.0;
/*
* Now merge the results from the MCV and histogram calculations,
* realizing that the histogram covers only the non-null values that
* are not listed in MCV.
*/
selec *= 1.0 - nullfrac - mcvsum;
selec += mcvsel;
}
else
selec = DEFAULT_PARENT_SEL;
ReleaseVariableStats(vardata);
/* result should be in range, but make sure... */
CLAMP_PROBABILITY(selec);
PG_RETURN_FLOAT8((float8) selec);
}
/*
* rangesel -- restriction selectivity for range operators
*/
Datum
rangesel(PG_FUNCTION_ARGS)
{
PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
Oid operator = PG_GETARG_OID(1);
List *args = (List *) PG_GETARG_POINTER(2);
int varRelid = PG_GETARG_INT32(3);
VariableStatData vardata;
Node *other;
bool varonleft;
Selectivity selec;
TypeCacheEntry *typcache = NULL;
RangeType *constrange = NULL;
/*
* If expression is not (variable op something) or (something op
* variable), then punt and return a default estimate.
*/
if (!get_restriction_variable(root, args, varRelid,
&vardata, &other, &varonleft))
PG_RETURN_FLOAT8(default_range_selectivity(operator));
/*
* Can't do anything useful if the something is not a constant, either.
*/
if (!IsA(other, Const))
{
ReleaseVariableStats(vardata);
PG_RETURN_FLOAT8(default_range_selectivity(operator));
}
/*
* All the range operators are strict, so we can cope with a NULL constant
* right away.
*/
if (((Const *) other)->constisnull)
{
ReleaseVariableStats(vardata);
PG_RETURN_FLOAT8(0.0);
}
/*
* If var is on the right, commute the operator, so that we can assume the
* var is on the left in what follows.
*/
if (!varonleft)
{
/* we have other Op var, commute to make var Op other */
operator = get_commutator(operator);
if (!operator)
{
/* Use default selectivity (should we raise an error instead?) */
ReleaseVariableStats(vardata);
PG_RETURN_FLOAT8(default_range_selectivity(operator));
}
}
/*
* OK, there's a Var and a Const we're dealing with here. We need the
* Const to be of same range type as the column, else we can't do anything
* useful. (Such cases will likely fail at runtime, but here we'd rather
* just return a default estimate.)
*
* If the operator is "range @> element", the constant should be of the
* element type of the range column. Convert it to a range that includes
* only that single point, so that we don't need special handling for that
* in what follows.
*/
if (operator == OID_RANGE_CONTAINS_ELEM_OP)
{
typcache = range_get_typcache(fcinfo, vardata.vartype);
if (((Const *) other)->consttype == typcache->rngelemtype->type_id)
{
RangeBound lower,
upper;
lower.inclusive = true;
lower.val = ((Const *) other)->constvalue;
lower.infinite = false;
lower.lower = true;
upper.inclusive = true;
upper.val = ((Const *) other)->constvalue;
upper.infinite = false;
upper.lower = false;
constrange = range_serialize(typcache, &lower, &upper, false);
}
}
else if (operator == OID_RANGE_ELEM_CONTAINED_OP)
{
/*
* Here, the Var is the elem, not the range. For now we just punt and
* return the default estimate. In future we could disassemble the
* range constant and apply scalarineqsel ...
*/
}
else if (((Const *) other)->consttype == vardata.vartype)
{
/* Both sides are the same range type */
typcache = range_get_typcache(fcinfo, vardata.vartype);
constrange = DatumGetRangeType(((Const *) other)->constvalue);
}
/*
* If we got a valid constant on one side of the operator, proceed to
* estimate using statistics. Otherwise punt and return a default constant
* estimate. Note that calc_rangesel need not handle
* OID_RANGE_ELEM_CONTAINED_OP.
*/
if (constrange)
selec = calc_rangesel(typcache, &vardata, constrange, operator);
else
selec = default_range_selectivity(operator);
ReleaseVariableStats(vardata);
CLAMP_PROBABILITY(selec);
PG_RETURN_FLOAT8((float8) selec);
}
/*
* _int_matchsel -- restriction selectivity function for intarray @@ query_int
*/
Datum
_int_matchsel(PG_FUNCTION_ARGS)
{
PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
List *args = (List *) PG_GETARG_POINTER(2);
int varRelid = PG_GETARG_INT32(3);
VariableStatData vardata;
Node *other;
bool varonleft;
Selectivity selec;
QUERYTYPE *query;
Datum *mcelems = NULL;
float4 *mcefreqs = NULL;
int nmcelems = 0;
float4 minfreq = 0.0;
float4 nullfrac = 0.0;
Form_pg_statistic stats;
Datum *values = NULL;
int nvalues = 0;
float4 *numbers = NULL;
int nnumbers = 0;
/*
* If expression is not "variable @@ something" or "something @@ variable"
* then punt and return a default estimate.
*/
if (!get_restriction_variable(root, args, varRelid,
&vardata, &other, &varonleft))
PG_RETURN_FLOAT8(DEFAULT_EQ_SEL);
/*
* Variable should be int[]. We don't support cases where variable is
* query_int.
*/
if (vardata.vartype != INT4ARRAYOID)
PG_RETURN_FLOAT8(DEFAULT_EQ_SEL);
/*
* Can't do anything useful if the something is not a constant, either.
*/
if (!IsA(other, Const))
{
ReleaseVariableStats(vardata);
PG_RETURN_FLOAT8(DEFAULT_EQ_SEL);
}
/*
* The "@@" operator is strict, so we can cope with NULL right away.
*/
if (((Const *) other)->constisnull)
{
ReleaseVariableStats(vardata);
PG_RETURN_FLOAT8(0.0);
}
/* The caller made sure the const is a query, so get it now */
query = DatumGetQueryTypeP(((Const *) other)->constvalue);
/* Empty query matches nothing */
if (query->size == 0)
{
ReleaseVariableStats(vardata);
return (Selectivity) 0.0;
}
/*
* Get the statistics for the intarray column.
*
* We're interested in the Most-Common-Elements list, and the NULL
* fraction.
*/
if (HeapTupleIsValid(vardata.statsTuple))
{
stats = (Form_pg_statistic) GETSTRUCT(vardata.statsTuple);
nullfrac = stats->stanullfrac;
/*
* For an int4 array, the default array type analyze function will
* collect a Most Common Elements list, which is an array of int4s.
*/
if (get_attstatsslot(vardata.statsTuple,
INT4OID, -1,
STATISTIC_KIND_MCELEM, InvalidOid,
NULL,
&values, &nvalues,
&numbers, &nnumbers))
{
/*
* There should be three more Numbers than Values, because the
* last three (for intarray) cells are taken for minimal, maximal
* and nulls frequency. Punt if not.
*/
if (nnumbers == nvalues + 3)
{
/* Grab the lowest frequency. */
minfreq = numbers[nnumbers - (nnumbers - nvalues)];
mcelems = values;
mcefreqs = numbers;
nmcelems = nvalues;
}
}
}
/* Process the logical expression in the query, using the stats */
selec = int_query_opr_selec(GETQUERY(query) + query->size - 1,
mcelems, mcefreqs, nmcelems, minfreq);
/* MCE stats count only non-null rows, so adjust for null rows. */
selec *= (1.0 - nullfrac);
free_attstatsslot(INT4OID, values, nvalues, numbers, nnumbers);
ReleaseVariableStats(vardata);
CLAMP_PROBABILITY(selec);
PG_RETURN_FLOAT8((float8) selec);
}
/*
* tsmatchsel -- Selectivity of "@@"
*
* restriction selectivity function for tsvector @@ tsquery and
* tsquery @@ tsvector
*/
Datum
tsmatchsel(PG_FUNCTION_ARGS)
{
PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
#ifdef NOT_USED
Oid operator = PG_GETARG_OID(1);
#endif
List *args = (List *) PG_GETARG_POINTER(2);
int varRelid = PG_GETARG_INT32(3);
VariableStatData vardata;
Node *other;
bool varonleft;
Selectivity selec;
/*
* If expression is not variable = something or something = variable, then
* punt and return a default estimate.
*/
if (!get_restriction_variable(root, args, varRelid,
&vardata, &other, &varonleft))
PG_RETURN_FLOAT8(DEFAULT_TS_MATCH_SEL);
/*
* Can't do anything useful if the something is not a constant, either.
*/
if (!IsA(other, Const))
{
ReleaseVariableStats(vardata);
PG_RETURN_FLOAT8(DEFAULT_TS_MATCH_SEL);
}
/*
* The "@@" operator is strict, so we can cope with NULL right away
*/
if (((Const *) other)->constisnull)
{
ReleaseVariableStats(vardata);
PG_RETURN_FLOAT8(0.0);
}
/*
* OK, there's a Var and a Const we're dealing with here. We need the
* Const to be a TSQuery, else we can't do anything useful. We have to
* check this because the Var might be the TSQuery not the TSVector.
*/
if (((Const *) other)->consttype == TSQUERYOID)
{
/* tsvector @@ tsquery or the other way around */
Assert(vardata.vartype == TSVECTOROID);
selec = tsquerysel(&vardata, ((Const *) other)->constvalue);
}
else
{
/* If we can't see the query structure, must punt */
selec = DEFAULT_TS_MATCH_SEL;
}
ReleaseVariableStats(vardata);
CLAMP_PROBABILITY(selec);
PG_RETURN_FLOAT8((float8) selec);
}
/*
* Selectivity estimation for the subnet inclusion/overlap operators
*/
Datum
networksel(PG_FUNCTION_ARGS)
{
PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
Oid operator = PG_GETARG_OID(1);
List *args = (List *) PG_GETARG_POINTER(2);
int varRelid = PG_GETARG_INT32(3);
VariableStatData vardata;
Node *other;
bool varonleft;
Selectivity selec,
mcv_selec,
non_mcv_selec;
Datum constvalue,
*hist_values;
int hist_nvalues;
Form_pg_statistic stats;
double sumcommon,
nullfrac;
FmgrInfo proc;
/*
* If expression is not (variable op something) or (something op
* variable), then punt and return a default estimate.
*/
if (!get_restriction_variable(root, args, varRelid,
&vardata, &other, &varonleft))
PG_RETURN_FLOAT8(DEFAULT_SEL(operator));
/*
* Can't do anything useful if the something is not a constant, either.
*/
if (!IsA(other, Const))
{
ReleaseVariableStats(vardata);
PG_RETURN_FLOAT8(DEFAULT_SEL(operator));
}
/* All of the operators handled here are strict. */
if (((Const *) other)->constisnull)
{
ReleaseVariableStats(vardata);
PG_RETURN_FLOAT8(0.0);
}
constvalue = ((Const *) other)->constvalue;
/* Otherwise, we need stats in order to produce a non-default estimate. */
if (!HeapTupleIsValid(vardata.statsTuple))
{
ReleaseVariableStats(vardata);
PG_RETURN_FLOAT8(DEFAULT_SEL(operator));
}
stats = (Form_pg_statistic) GETSTRUCT(vardata.statsTuple);
nullfrac = stats->stanullfrac;
/*
* If we have most-common-values info, add up the fractions of the MCV
* entries that satisfy MCV OP CONST. These fractions contribute directly
* to the result selectivity. Also add up the total fraction represented
* by MCV entries.
*/
fmgr_info(get_opcode(operator), &proc);
mcv_selec = mcv_selectivity(&vardata, &proc, constvalue, varonleft,
&sumcommon);
/*
* If we have a histogram, use it to estimate the proportion of the
* non-MCV population that satisfies the clause. If we don't, apply the
* default selectivity to that population.
*/
if (get_attstatsslot(vardata.statsTuple,
vardata.atttype, vardata.atttypmod,
STATISTIC_KIND_HISTOGRAM, InvalidOid,
NULL,
&hist_values, &hist_nvalues,
NULL, NULL))
{
int opr_codenum = inet_opr_codenum(operator);
/* Commute if needed, so we can consider histogram to be on the left */
if (!varonleft)
opr_codenum = -opr_codenum;
non_mcv_selec = inet_hist_value_sel(hist_values, hist_nvalues,
constvalue, opr_codenum);
free_attstatsslot(vardata.atttype, hist_values, hist_nvalues, NULL, 0);
}
else
non_mcv_selec = DEFAULT_SEL(operator);
/* Combine selectivities for MCV and non-MCV populations */
selec = mcv_selec + (1.0 - nullfrac - sumcommon) * non_mcv_selec;
/* Result should be in range, but make sure... */
CLAMP_PROBABILITY(selec);
ReleaseVariableStats(vardata);
PG_RETURN_FLOAT8(selec);
}
