Adding upstream version 13.4.upstream/13.4upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 333 insertions, 0 deletions

diff --git a/contrib/intarray/_int_selfuncs.c b/contrib/intarray/_int_selfuncs.c
new file mode 100644
index 0000000..a3a538a
--- /dev/null
+++ b/contrib/intarray/_int_selfuncs.c
@@ -0,0 +1,333 @@
+/*-------------------------------------------------------------------------
+ *
+ * _int_selfuncs.c
+ *	  Functions for selectivity estimation of intarray operators
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  contrib/intarray/_int_selfuncs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "_int.h"
+#include "access/htup_details.h"
+#include "catalog/pg_operator.h"
+#include "catalog/pg_statistic.h"
+#include "catalog/pg_type.h"
+#include "miscadmin.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/selfuncs.h"
+#include "utils/syscache.h"
+
+PG_FUNCTION_INFO_V1(_int_overlap_sel);
+PG_FUNCTION_INFO_V1(_int_contains_sel);
+PG_FUNCTION_INFO_V1(_int_contained_sel);
+PG_FUNCTION_INFO_V1(_int_overlap_joinsel);
+PG_FUNCTION_INFO_V1(_int_contains_joinsel);
+PG_FUNCTION_INFO_V1(_int_contained_joinsel);
+PG_FUNCTION_INFO_V1(_int_matchsel);
+
+
+static Selectivity int_query_opr_selec(ITEM *item, Datum *values, float4 *freqs,
+									   int nmncelems, float4 minfreq);
+static int	compare_val_int4(const void *a, const void *b);
+
+/*
+ * Wrappers around the default array selectivity estimation functions.
+ *
+ * The default array selectivity operators for the @>, && and @< operators
+ * work fine for integer arrays. However, if we tried to just use arraycontsel
+ * and arraycontjoinsel directly as the cost estimator functions for our
+ * operators, they would not work as intended, because they look at the
+ * operator's OID. Our operators behave exactly like the built-in anyarray
+ * versions, but we must tell the cost estimator functions which built-in
+ * operators they correspond to. These wrappers just replace the operator
+ * OID with the corresponding built-in operator's OID, and call the built-in
+ * function.
+ */
+
+Datum
+_int_overlap_sel(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_DATUM(DirectFunctionCall4(arraycontsel,
+										PG_GETARG_DATUM(0),
+										ObjectIdGetDatum(OID_ARRAY_OVERLAP_OP),
+										PG_GETARG_DATUM(2),
+										PG_GETARG_DATUM(3)));
+}
+
+Datum
+_int_contains_sel(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_DATUM(DirectFunctionCall4(arraycontsel,
+										PG_GETARG_DATUM(0),
+										ObjectIdGetDatum(OID_ARRAY_CONTAINS_OP),
+										PG_GETARG_DATUM(2),
+										PG_GETARG_DATUM(3)));
+}
+
+Datum
+_int_contained_sel(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_DATUM(DirectFunctionCall4(arraycontsel,
+										PG_GETARG_DATUM(0),
+										ObjectIdGetDatum(OID_ARRAY_CONTAINED_OP),
+										PG_GETARG_DATUM(2),
+										PG_GETARG_DATUM(3)));
+}
+
+Datum
+_int_overlap_joinsel(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_DATUM(DirectFunctionCall5(arraycontjoinsel,
+										PG_GETARG_DATUM(0),
+										ObjectIdGetDatum(OID_ARRAY_OVERLAP_OP),
+										PG_GETARG_DATUM(2),
+										PG_GETARG_DATUM(3),
+										PG_GETARG_DATUM(4)));
+}
+
+Datum
+_int_contains_joinsel(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_DATUM(DirectFunctionCall5(arraycontjoinsel,
+										PG_GETARG_DATUM(0),
+										ObjectIdGetDatum(OID_ARRAY_CONTAINS_OP),
+										PG_GETARG_DATUM(2),
+										PG_GETARG_DATUM(3),
+										PG_GETARG_DATUM(4)));
+}
+
+Datum
+_int_contained_joinsel(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_DATUM(DirectFunctionCall5(arraycontjoinsel,
+										PG_GETARG_DATUM(0),
+										ObjectIdGetDatum(OID_ARRAY_CONTAINED_OP),
+										PG_GETARG_DATUM(2),
+										PG_GETARG_DATUM(3),
+										PG_GETARG_DATUM(4)));
+}
+
+
+/*
+ * _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;
+	AttStatsSlot sslot;
+
+	/*
+	 * 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))
+	{
+		Form_pg_statistic stats;
+
+		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(&sslot, vardata.statsTuple,
+							 STATISTIC_KIND_MCELEM, InvalidOid,
+							 ATTSTATSSLOT_VALUES | ATTSTATSSLOT_NUMBERS))
+		{
+			Assert(sslot.valuetype == INT4OID);
+
+			/*
+			 * 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 (sslot.nnumbers == sslot.nvalues + 3)
+			{
+				/* Grab the lowest frequency. */
+				minfreq = sslot.numbers[sslot.nnumbers - (sslot.nnumbers - sslot.nvalues)];
+
+				mcelems = sslot.values;
+				mcefreqs = sslot.numbers;
+				nmcelems = sslot.nvalues;
+			}
+		}
+	}
+	else
+		memset(&sslot, 0, sizeof(sslot));
+
+	/* 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(&sslot);
+	ReleaseVariableStats(vardata);
+
+	CLAMP_PROBABILITY(selec);
+
+	PG_RETURN_FLOAT8((float8) selec);
+}
+
+/*
+ * Estimate selectivity of single intquery operator
+ */
+static Selectivity
+int_query_opr_selec(ITEM *item, Datum *mcelems, float4 *mcefreqs,
+					int nmcelems, float4 minfreq)
+{
+	Selectivity selec;
+
+	/* since this function recurses, it could be driven to stack overflow */
+	check_stack_depth();
+
+	if (item->type == VAL)
+	{
+		Datum	   *searchres;
+
+		if (mcelems == NULL)
+			return (Selectivity) DEFAULT_EQ_SEL;
+
+		searchres = (Datum *) bsearch(&item->val, mcelems, nmcelems,
+									  sizeof(Datum), compare_val_int4);
+		if (searchres)
+		{
+			/*
+			 * The element is in MCELEM.  Return precise selectivity (or at
+			 * least as precise as ANALYZE could find out).
+			 */
+			selec = mcefreqs[searchres - mcelems];
+		}
+		else
+		{
+			/*
+			 * The element is not in MCELEM.  Punt, but assume that the
+			 * selectivity cannot be more than minfreq / 2.
+			 */
+			selec = Min(DEFAULT_EQ_SEL, minfreq / 2);
+		}
+	}
+	else if (item->type == OPR)
+	{
+		/* Current query node is an operator */
+		Selectivity s1,
+					s2;
+
+		s1 = int_query_opr_selec(item - 1, mcelems, mcefreqs, nmcelems,
+								 minfreq);
+		switch (item->val)
+		{
+			case (int32) '!':
+				selec = 1.0 - s1;
+				break;
+
+			case (int32) '&':
+				s2 = int_query_opr_selec(item + item->left, mcelems, mcefreqs,
+										 nmcelems, minfreq);
+				selec = s1 * s2;
+				break;
+
+			case (int32) '|':
+				s2 = int_query_opr_selec(item + item->left, mcelems, mcefreqs,
+										 nmcelems, minfreq);
+				selec = s1 + s2 - s1 * s2;
+				break;
+
+			default:
+				elog(ERROR, "unrecognized operator: %d", item->val);
+				selec = 0;		/* keep compiler quiet */
+				break;
+		}
+	}
+	else
+	{
+		elog(ERROR, "unrecognized int query item type: %u", item->type);
+		selec = 0;				/* keep compiler quiet */
+	}
+
+	/* Clamp intermediate results to stay sane despite roundoff error */
+	CLAMP_PROBABILITY(selec);
+
+	return selec;
+}
+
+/*
+ * Comparison function for binary search in mcelem array.
+ */
+static int
+compare_val_int4(const void *a, const void *b)
+{
+	int32		key = *(int32 *) a;
+	const Datum *t = (const Datum *) b;
+
+	return key - DatumGetInt32(*t);
+}