Adding upstream version 16.2.upstream/16.2

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

1 files changed, 2893 insertions, 0 deletions

diff --git a/src/backend/utils/adt/tsvector_op.c b/src/backend/utils/adt/tsvector_op.c
new file mode 100644
index 0000000..4457c5d
--- /dev/null
+++ b/src/backend/utils/adt/tsvector_op.c
@@ -0,0 +1,2893 @@
+/*-------------------------------------------------------------------------
+ *
+ * tsvector_op.c
+ *	  operations over tsvector
+ *
+ * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/tsvector_op.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include <limits.h>
+
+#include "access/htup_details.h"
+#include "catalog/namespace.h"
+#include "catalog/pg_type.h"
+#include "commands/trigger.h"
+#include "executor/spi.h"
+#include "funcapi.h"
+#include "lib/qunique.h"
+#include "mb/pg_wchar.h"
+#include "miscadmin.h"
+#include "parser/parse_coerce.h"
+#include "tsearch/ts_utils.h"
+#include "utils/array.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/regproc.h"
+#include "utils/rel.h"
+
+
+typedef struct
+{
+	WordEntry  *arrb;
+	WordEntry  *arre;
+	char	   *values;
+	char	   *operand;
+} CHKVAL;
+
+
+typedef struct StatEntry
+{
+	uint32		ndoc;			/* zero indicates that we were already here
+								 * while walking through the tree */
+	uint32		nentry;
+	struct StatEntry *left;
+	struct StatEntry *right;
+	uint32		lenlexeme;
+	char		lexeme[FLEXIBLE_ARRAY_MEMBER];
+} StatEntry;
+
+#define STATENTRYHDRSZ	(offsetof(StatEntry, lexeme))
+
+typedef struct
+{
+	int32		weight;
+
+	uint32		maxdepth;
+
+	StatEntry **stack;
+	uint32		stackpos;
+
+	StatEntry  *root;
+} TSVectorStat;
+
+
+static TSTernaryValue TS_execute_recurse(QueryItem *curitem, void *arg,
+										 uint32 flags,
+										 TSExecuteCallback chkcond);
+static bool TS_execute_locations_recurse(QueryItem *curitem,
+										 void *arg,
+										 TSExecuteCallback chkcond,
+										 List **locations);
+static int	tsvector_bsearch(const TSVector tsv, char *lexeme, int lexeme_len);
+static Datum tsvector_update_trigger(PG_FUNCTION_ARGS, bool config_column);
+
+
+/*
+ * Order: haspos, len, word, for all positions (pos, weight)
+ */
+static int
+silly_cmp_tsvector(const TSVector a, const TSVector b)
+{
+	if (VARSIZE(a) < VARSIZE(b))
+		return -1;
+	else if (VARSIZE(a) > VARSIZE(b))
+		return 1;
+	else if (a->size < b->size)
+		return -1;
+	else if (a->size > b->size)
+		return 1;
+	else
+	{
+		WordEntry  *aptr = ARRPTR(a);
+		WordEntry  *bptr = ARRPTR(b);
+		int			i = 0;
+		int			res;
+
+
+		for (i = 0; i < a->size; i++)
+		{
+			if (aptr->haspos != bptr->haspos)
+			{
+				return (aptr->haspos > bptr->haspos) ? -1 : 1;
+			}
+			else if ((res = tsCompareString(STRPTR(a) + aptr->pos, aptr->len, STRPTR(b) + bptr->pos, bptr->len, false)) != 0)
+			{
+				return res;
+			}
+			else if (aptr->haspos)
+			{
+				WordEntryPos *ap = POSDATAPTR(a, aptr);
+				WordEntryPos *bp = POSDATAPTR(b, bptr);
+				int			j;
+
+				if (POSDATALEN(a, aptr) != POSDATALEN(b, bptr))
+					return (POSDATALEN(a, aptr) > POSDATALEN(b, bptr)) ? -1 : 1;
+
+				for (j = 0; j < POSDATALEN(a, aptr); j++)
+				{
+					if (WEP_GETPOS(*ap) != WEP_GETPOS(*bp))
+					{
+						return (WEP_GETPOS(*ap) > WEP_GETPOS(*bp)) ? -1 : 1;
+					}
+					else if (WEP_GETWEIGHT(*ap) != WEP_GETWEIGHT(*bp))
+					{
+						return (WEP_GETWEIGHT(*ap) > WEP_GETWEIGHT(*bp)) ? -1 : 1;
+					}
+					ap++, bp++;
+				}
+			}
+
+			aptr++;
+			bptr++;
+		}
+	}
+
+	return 0;
+}
+
+#define TSVECTORCMPFUNC( type, action, ret )			\
+Datum													\
+tsvector_##type(PG_FUNCTION_ARGS)						\
+{														\
+	TSVector	a = PG_GETARG_TSVECTOR(0);				\
+	TSVector	b = PG_GETARG_TSVECTOR(1);				\
+	int			res = silly_cmp_tsvector(a, b);			\
+	PG_FREE_IF_COPY(a,0);								\
+	PG_FREE_IF_COPY(b,1);								\
+	PG_RETURN_##ret( res action 0 );					\
+}	\
+/* keep compiler quiet - no extra ; */					\
+extern int no_such_variable
+
+TSVECTORCMPFUNC(lt, <, BOOL);
+TSVECTORCMPFUNC(le, <=, BOOL);
+TSVECTORCMPFUNC(eq, ==, BOOL);
+TSVECTORCMPFUNC(ge, >=, BOOL);
+TSVECTORCMPFUNC(gt, >, BOOL);
+TSVECTORCMPFUNC(ne, !=, BOOL);
+TSVECTORCMPFUNC(cmp, +, INT32);
+
+Datum
+tsvector_strip(PG_FUNCTION_ARGS)
+{
+	TSVector	in = PG_GETARG_TSVECTOR(0);
+	TSVector	out;
+	int			i,
+				len = 0;
+	WordEntry  *arrin = ARRPTR(in),
+			   *arrout;
+	char	   *cur;
+
+	for (i = 0; i < in->size; i++)
+		len += arrin[i].len;
+
+	len = CALCDATASIZE(in->size, len);
+	out = (TSVector) palloc0(len);
+	SET_VARSIZE(out, len);
+	out->size = in->size;
+	arrout = ARRPTR(out);
+	cur = STRPTR(out);
+	for (i = 0; i < in->size; i++)
+	{
+		memcpy(cur, STRPTR(in) + arrin[i].pos, arrin[i].len);
+		arrout[i].haspos = 0;
+		arrout[i].len = arrin[i].len;
+		arrout[i].pos = cur - STRPTR(out);
+		cur += arrout[i].len;
+	}
+
+	PG_FREE_IF_COPY(in, 0);
+	PG_RETURN_POINTER(out);
+}
+
+Datum
+tsvector_length(PG_FUNCTION_ARGS)
+{
+	TSVector	in = PG_GETARG_TSVECTOR(0);
+	int32		ret = in->size;
+
+	PG_FREE_IF_COPY(in, 0);
+	PG_RETURN_INT32(ret);
+}
+
+Datum
+tsvector_setweight(PG_FUNCTION_ARGS)
+{
+	TSVector	in = PG_GETARG_TSVECTOR(0);
+	char		cw = PG_GETARG_CHAR(1);
+	TSVector	out;
+	int			i,
+				j;
+	WordEntry  *entry;
+	WordEntryPos *p;
+	int			w = 0;
+
+	switch (cw)
+	{
+		case 'A':
+		case 'a':
+			w = 3;
+			break;
+		case 'B':
+		case 'b':
+			w = 2;
+			break;
+		case 'C':
+		case 'c':
+			w = 1;
+			break;
+		case 'D':
+		case 'd':
+			w = 0;
+			break;
+		default:
+			/* internal error */
+			elog(ERROR, "unrecognized weight: %d", cw);
+	}
+
+	out = (TSVector) palloc(VARSIZE(in));
+	memcpy(out, in, VARSIZE(in));
+	entry = ARRPTR(out);
+	i = out->size;
+	while (i--)
+	{
+		if ((j = POSDATALEN(out, entry)) != 0)
+		{
+			p = POSDATAPTR(out, entry);
+			while (j--)
+			{
+				WEP_SETWEIGHT(*p, w);
+				p++;
+			}
+		}
+		entry++;
+	}
+
+	PG_FREE_IF_COPY(in, 0);
+	PG_RETURN_POINTER(out);
+}
+
+/*
+ * setweight(tsin tsvector, char_weight "char", lexemes "text"[])
+ *
+ * Assign weight w to elements of tsin that are listed in lexemes.
+ */
+Datum
+tsvector_setweight_by_filter(PG_FUNCTION_ARGS)
+{
+	TSVector	tsin = PG_GETARG_TSVECTOR(0);
+	char		char_weight = PG_GETARG_CHAR(1);
+	ArrayType  *lexemes = PG_GETARG_ARRAYTYPE_P(2);
+
+	TSVector	tsout;
+	int			i,
+				j,
+				nlexemes,
+				weight;
+	WordEntry  *entry;
+	Datum	   *dlexemes;
+	bool	   *nulls;
+
+	switch (char_weight)
+	{
+		case 'A':
+		case 'a':
+			weight = 3;
+			break;
+		case 'B':
+		case 'b':
+			weight = 2;
+			break;
+		case 'C':
+		case 'c':
+			weight = 1;
+			break;
+		case 'D':
+		case 'd':
+			weight = 0;
+			break;
+		default:
+			/* internal error */
+			elog(ERROR, "unrecognized weight: %c", char_weight);
+	}
+
+	tsout = (TSVector) palloc(VARSIZE(tsin));
+	memcpy(tsout, tsin, VARSIZE(tsin));
+	entry = ARRPTR(tsout);
+
+	deconstruct_array_builtin(lexemes, TEXTOID, &dlexemes, &nulls, &nlexemes);
+
+	/*
+	 * Assuming that lexemes array is significantly shorter than tsvector we
+	 * can iterate through lexemes performing binary search of each lexeme
+	 * from lexemes in tsvector.
+	 */
+	for (i = 0; i < nlexemes; i++)
+	{
+		char	   *lex;
+		int			lex_len,
+					lex_pos;
+
+		/* Ignore null array elements, they surely don't match */
+		if (nulls[i])
+			continue;
+
+		lex = VARDATA(dlexemes[i]);
+		lex_len = VARSIZE(dlexemes[i]) - VARHDRSZ;
+		lex_pos = tsvector_bsearch(tsout, lex, lex_len);
+
+		if (lex_pos >= 0 && (j = POSDATALEN(tsout, entry + lex_pos)) != 0)
+		{
+			WordEntryPos *p = POSDATAPTR(tsout, entry + lex_pos);
+
+			while (j--)
+			{
+				WEP_SETWEIGHT(*p, weight);
+				p++;
+			}
+		}
+	}
+
+	PG_FREE_IF_COPY(tsin, 0);
+	PG_FREE_IF_COPY(lexemes, 2);
+
+	PG_RETURN_POINTER(tsout);
+}
+
+#define compareEntry(pa, a, pb, b) \
+	tsCompareString((pa) + (a)->pos, (a)->len,	\
+					(pb) + (b)->pos, (b)->len,	\
+					false)
+
+/*
+ * Add positions from src to dest after offsetting them by maxpos.
+ * Return the number added (might be less than expected due to overflow)
+ */
+static int32
+add_pos(TSVector src, WordEntry *srcptr,
+		TSVector dest, WordEntry *destptr,
+		int32 maxpos)
+{
+	uint16	   *clen = &_POSVECPTR(dest, destptr)->npos;
+	int			i;
+	uint16		slen = POSDATALEN(src, srcptr),
+				startlen;
+	WordEntryPos *spos = POSDATAPTR(src, srcptr),
+			   *dpos = POSDATAPTR(dest, destptr);
+
+	if (!destptr->haspos)
+		*clen = 0;
+
+	startlen = *clen;
+	for (i = 0;
+		 i < slen && *clen < MAXNUMPOS &&
+		 (*clen == 0 || WEP_GETPOS(dpos[*clen - 1]) != MAXENTRYPOS - 1);
+		 i++)
+	{
+		WEP_SETWEIGHT(dpos[*clen], WEP_GETWEIGHT(spos[i]));
+		WEP_SETPOS(dpos[*clen], LIMITPOS(WEP_GETPOS(spos[i]) + maxpos));
+		(*clen)++;
+	}
+
+	if (*clen != startlen)
+		destptr->haspos = 1;
+	return *clen - startlen;
+}
+
+/*
+ * Perform binary search of given lexeme in TSVector.
+ * Returns lexeme position in TSVector's entry array or -1 if lexeme wasn't
+ * found.
+ */
+static int
+tsvector_bsearch(const TSVector tsv, char *lexeme, int lexeme_len)
+{
+	WordEntry  *arrin = ARRPTR(tsv);
+	int			StopLow = 0,
+				StopHigh = tsv->size,
+				StopMiddle,
+				cmp;
+
+	while (StopLow < StopHigh)
+	{
+		StopMiddle = (StopLow + StopHigh) / 2;
+
+		cmp = tsCompareString(lexeme, lexeme_len,
+							  STRPTR(tsv) + arrin[StopMiddle].pos,
+							  arrin[StopMiddle].len,
+							  false);
+
+		if (cmp < 0)
+			StopHigh = StopMiddle;
+		else if (cmp > 0)
+			StopLow = StopMiddle + 1;
+		else					/* found it */
+			return StopMiddle;
+	}
+
+	return -1;
+}
+
+/*
+ * qsort comparator functions
+ */
+
+static int
+compare_int(const void *va, const void *vb)
+{
+	int			a = *((const int *) va);
+	int			b = *((const int *) vb);
+
+	if (a == b)
+		return 0;
+	return (a > b) ? 1 : -1;
+}
+
+static int
+compare_text_lexemes(const void *va, const void *vb)
+{
+	Datum		a = *((const Datum *) va);
+	Datum		b = *((const Datum *) vb);
+	char	   *alex = VARDATA_ANY(a);
+	int			alex_len = VARSIZE_ANY_EXHDR(a);
+	char	   *blex = VARDATA_ANY(b);
+	int			blex_len = VARSIZE_ANY_EXHDR(b);
+
+	return tsCompareString(alex, alex_len, blex, blex_len, false);
+}
+
+/*
+ * Internal routine to delete lexemes from TSVector by array of offsets.
+ *
+ * int *indices_to_delete -- array of lexeme offsets to delete (modified here!)
+ * int indices_count -- size of that array
+ *
+ * Returns new TSVector without given lexemes along with their positions
+ * and weights.
+ */
+static TSVector
+tsvector_delete_by_indices(TSVector tsv, int *indices_to_delete,
+						   int indices_count)
+{
+	TSVector	tsout;
+	WordEntry  *arrin = ARRPTR(tsv),
+			   *arrout;
+	char	   *data = STRPTR(tsv),
+			   *dataout;
+	int			i,				/* index in arrin */
+				j,				/* index in arrout */
+				k,				/* index in indices_to_delete */
+				curoff;			/* index in dataout area */
+
+	/*
+	 * Sort the filter array to simplify membership checks below.  Also, get
+	 * rid of any duplicate entries, so that we can assume that indices_count
+	 * is exactly equal to the number of lexemes that will be removed.
+	 */
+	if (indices_count > 1)
+	{
+		qsort(indices_to_delete, indices_count, sizeof(int), compare_int);
+		indices_count = qunique(indices_to_delete, indices_count, sizeof(int),
+								compare_int);
+	}
+
+	/*
+	 * Here we overestimate tsout size, since we don't know how much space is
+	 * used by the deleted lexeme(s).  We will set exact size below.
+	 */
+	tsout = (TSVector) palloc0(VARSIZE(tsv));
+
+	/* This count must be correct because STRPTR(tsout) relies on it. */
+	tsout->size = tsv->size - indices_count;
+
+	/*
+	 * Copy tsv to tsout, skipping lexemes listed in indices_to_delete.
+	 */
+	arrout = ARRPTR(tsout);
+	dataout = STRPTR(tsout);
+	curoff = 0;
+	for (i = j = k = 0; i < tsv->size; i++)
+	{
+		/*
+		 * If current i is present in indices_to_delete, skip this lexeme.
+		 * Since indices_to_delete is already sorted, we only need to check
+		 * the current (k'th) entry.
+		 */
+		if (k < indices_count && i == indices_to_delete[k])
+		{
+			k++;
+			continue;
+		}
+
+		/* Copy lexeme and its positions and weights */
+		memcpy(dataout + curoff, data + arrin[i].pos, arrin[i].len);
+		arrout[j].haspos = arrin[i].haspos;
+		arrout[j].len = arrin[i].len;
+		arrout[j].pos = curoff;
+		curoff += arrin[i].len;
+		if (arrin[i].haspos)
+		{
+			int			len = POSDATALEN(tsv, arrin + i) * sizeof(WordEntryPos)
+				+ sizeof(uint16);
+
+			curoff = SHORTALIGN(curoff);
+			memcpy(dataout + curoff,
+				   STRPTR(tsv) + SHORTALIGN(arrin[i].pos + arrin[i].len),
+				   len);
+			curoff += len;
+		}
+
+		j++;
+	}
+
+	/*
+	 * k should now be exactly equal to indices_count. If it isn't then the
+	 * caller provided us with indices outside of [0, tsv->size) range and
+	 * estimation of tsout's size is wrong.
+	 */
+	Assert(k == indices_count);
+
+	SET_VARSIZE(tsout, CALCDATASIZE(tsout->size, curoff));
+	return tsout;
+}
+
+/*
+ * Delete given lexeme from tsvector.
+ * Implementation of user-level ts_delete(tsvector, text).
+ */
+Datum
+tsvector_delete_str(PG_FUNCTION_ARGS)
+{
+	TSVector	tsin = PG_GETARG_TSVECTOR(0),
+				tsout;
+	text	   *tlexeme = PG_GETARG_TEXT_PP(1);
+	char	   *lexeme = VARDATA_ANY(tlexeme);
+	int			lexeme_len = VARSIZE_ANY_EXHDR(tlexeme),
+				skip_index;
+
+	if ((skip_index = tsvector_bsearch(tsin, lexeme, lexeme_len)) == -1)
+		PG_RETURN_POINTER(tsin);
+
+	tsout = tsvector_delete_by_indices(tsin, &skip_index, 1);
+
+	PG_FREE_IF_COPY(tsin, 0);
+	PG_FREE_IF_COPY(tlexeme, 1);
+	PG_RETURN_POINTER(tsout);
+}
+
+/*
+ * Delete given array of lexemes from tsvector.
+ * Implementation of user-level ts_delete(tsvector, text[]).
+ */
+Datum
+tsvector_delete_arr(PG_FUNCTION_ARGS)
+{
+	TSVector	tsin = PG_GETARG_TSVECTOR(0),
+				tsout;
+	ArrayType  *lexemes = PG_GETARG_ARRAYTYPE_P(1);
+	int			i,
+				nlex,
+				skip_count,
+			   *skip_indices;
+	Datum	   *dlexemes;
+	bool	   *nulls;
+
+	deconstruct_array_builtin(lexemes, TEXTOID, &dlexemes, &nulls, &nlex);
+
+	/*
+	 * In typical use case array of lexemes to delete is relatively small. So
+	 * here we optimize things for that scenario: iterate through lexarr
+	 * performing binary search of each lexeme from lexarr in tsvector.
+	 */
+	skip_indices = palloc0(nlex * sizeof(int));
+	for (i = skip_count = 0; i < nlex; i++)
+	{
+		char	   *lex;
+		int			lex_len,
+					lex_pos;
+
+		/* Ignore null array elements, they surely don't match */
+		if (nulls[i])
+			continue;
+
+		lex = VARDATA(dlexemes[i]);
+		lex_len = VARSIZE(dlexemes[i]) - VARHDRSZ;
+		lex_pos = tsvector_bsearch(tsin, lex, lex_len);
+
+		if (lex_pos >= 0)
+			skip_indices[skip_count++] = lex_pos;
+	}
+
+	tsout = tsvector_delete_by_indices(tsin, skip_indices, skip_count);
+
+	pfree(skip_indices);
+	PG_FREE_IF_COPY(tsin, 0);
+	PG_FREE_IF_COPY(lexemes, 1);
+
+	PG_RETURN_POINTER(tsout);
+}
+
+/*
+ * Expand tsvector as table with following columns:
+ *	   lexeme: lexeme text
+ *	   positions: integer array of lexeme positions
+ *	   weights: char array of weights corresponding to positions
+ */
+Datum
+tsvector_unnest(PG_FUNCTION_ARGS)
+{
+	FuncCallContext *funcctx;
+	TSVector	tsin;
+
+	if (SRF_IS_FIRSTCALL())
+	{
+		MemoryContext oldcontext;
+		TupleDesc	tupdesc;
+
+		funcctx = SRF_FIRSTCALL_INIT();
+		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
+
+		tupdesc = CreateTemplateTupleDesc(3);
+		TupleDescInitEntry(tupdesc, (AttrNumber) 1, "lexeme",
+						   TEXTOID, -1, 0);
+		TupleDescInitEntry(tupdesc, (AttrNumber) 2, "positions",
+						   INT2ARRAYOID, -1, 0);
+		TupleDescInitEntry(tupdesc, (AttrNumber) 3, "weights",
+						   TEXTARRAYOID, -1, 0);
+		if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
+			elog(ERROR, "return type must be a row type");
+		funcctx->tuple_desc = tupdesc;
+
+		funcctx->user_fctx = PG_GETARG_TSVECTOR_COPY(0);
+
+		MemoryContextSwitchTo(oldcontext);
+	}
+
+	funcctx = SRF_PERCALL_SETUP();
+	tsin = (TSVector) funcctx->user_fctx;
+
+	if (funcctx->call_cntr < tsin->size)
+	{
+		WordEntry  *arrin = ARRPTR(tsin);
+		char	   *data = STRPTR(tsin);
+		HeapTuple	tuple;
+		int			j,
+					i = funcctx->call_cntr;
+		bool		nulls[] = {false, false, false};
+		Datum		values[3];
+
+		values[0] = PointerGetDatum(cstring_to_text_with_len(data + arrin[i].pos, arrin[i].len));
+
+		if (arrin[i].haspos)
+		{
+			WordEntryPosVector *posv;
+			Datum	   *positions;
+			Datum	   *weights;
+			char		weight;
+
+			/*
+			 * Internally tsvector stores position and weight in the same
+			 * uint16 (2 bits for weight, 14 for position). Here we extract
+			 * that in two separate arrays.
+			 */
+			posv = _POSVECPTR(tsin, arrin + i);
+			positions = palloc(posv->npos * sizeof(Datum));
+			weights = palloc(posv->npos * sizeof(Datum));
+			for (j = 0; j < posv->npos; j++)
+			{
+				positions[j] = Int16GetDatum(WEP_GETPOS(posv->pos[j]));
+				weight = 'D' - WEP_GETWEIGHT(posv->pos[j]);
+				weights[j] = PointerGetDatum(cstring_to_text_with_len(&weight,
+																	  1));
+			}
+
+			values[1] = PointerGetDatum(construct_array_builtin(positions, posv->npos, INT2OID));
+			values[2] = PointerGetDatum(construct_array_builtin(weights, posv->npos, TEXTOID));
+		}
+		else
+		{
+			nulls[1] = nulls[2] = true;
+		}
+
+		tuple = heap_form_tuple(funcctx->tuple_desc, values, nulls);
+		SRF_RETURN_NEXT(funcctx, HeapTupleGetDatum(tuple));
+	}
+	else
+	{
+		SRF_RETURN_DONE(funcctx);
+	}
+}
+
+/*
+ * Convert tsvector to array of lexemes.
+ */
+Datum
+tsvector_to_array(PG_FUNCTION_ARGS)
+{
+	TSVector	tsin = PG_GETARG_TSVECTOR(0);
+	WordEntry  *arrin = ARRPTR(tsin);
+	Datum	   *elements;
+	int			i;
+	ArrayType  *array;
+
+	elements = palloc(tsin->size * sizeof(Datum));
+
+	for (i = 0; i < tsin->size; i++)
+	{
+		elements[i] = PointerGetDatum(cstring_to_text_with_len(STRPTR(tsin) + arrin[i].pos,
+															   arrin[i].len));
+	}
+
+	array = construct_array_builtin(elements, tsin->size, TEXTOID);
+
+	pfree(elements);
+	PG_FREE_IF_COPY(tsin, 0);
+	PG_RETURN_POINTER(array);
+}
+
+/*
+ * Build tsvector from array of lexemes.
+ */
+Datum
+array_to_tsvector(PG_FUNCTION_ARGS)
+{
+	ArrayType  *v = PG_GETARG_ARRAYTYPE_P(0);
+	TSVector	tsout;
+	Datum	   *dlexemes;
+	WordEntry  *arrout;
+	bool	   *nulls;
+	int			nitems,
+				i,
+				tslen,
+				datalen = 0;
+	char	   *cur;
+
+	deconstruct_array_builtin(v, TEXTOID, &dlexemes, &nulls, &nitems);
+
+	/*
+	 * Reject nulls and zero length strings (maybe we should just ignore them,
+	 * instead?)
+	 */
+	for (i = 0; i < nitems; i++)
+	{
+		if (nulls[i])
+			ereport(ERROR,
+					(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+					 errmsg("lexeme array may not contain nulls")));
+
+		if (VARSIZE(dlexemes[i]) - VARHDRSZ == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_ZERO_LENGTH_CHARACTER_STRING),
+					 errmsg("lexeme array may not contain empty strings")));
+	}
+
+	/* Sort and de-dup, because this is required for a valid tsvector. */
+	if (nitems > 1)
+	{
+		qsort(dlexemes, nitems, sizeof(Datum), compare_text_lexemes);
+		nitems = qunique(dlexemes, nitems, sizeof(Datum),
+						 compare_text_lexemes);
+	}
+
+	/* Calculate space needed for surviving lexemes. */
+	for (i = 0; i < nitems; i++)
+		datalen += VARSIZE(dlexemes[i]) - VARHDRSZ;
+	tslen = CALCDATASIZE(nitems, datalen);
+
+	/* Allocate and fill tsvector. */
+	tsout = (TSVector) palloc0(tslen);
+	SET_VARSIZE(tsout, tslen);
+	tsout->size = nitems;
+
+	arrout = ARRPTR(tsout);
+	cur = STRPTR(tsout);
+	for (i = 0; i < nitems; i++)
+	{
+		char	   *lex = VARDATA(dlexemes[i]);
+		int			lex_len = VARSIZE(dlexemes[i]) - VARHDRSZ;
+
+		memcpy(cur, lex, lex_len);
+		arrout[i].haspos = 0;
+		arrout[i].len = lex_len;
+		arrout[i].pos = cur - STRPTR(tsout);
+		cur += lex_len;
+	}
+
+	PG_FREE_IF_COPY(v, 0);
+	PG_RETURN_POINTER(tsout);
+}
+
+/*
+ * ts_filter(): keep only lexemes with given weights in tsvector.
+ */
+Datum
+tsvector_filter(PG_FUNCTION_ARGS)
+{
+	TSVector	tsin = PG_GETARG_TSVECTOR(0),
+				tsout;
+	ArrayType  *weights = PG_GETARG_ARRAYTYPE_P(1);
+	WordEntry  *arrin = ARRPTR(tsin),
+			   *arrout;
+	char	   *datain = STRPTR(tsin),
+			   *dataout;
+	Datum	   *dweights;
+	bool	   *nulls;
+	int			nweights;
+	int			i,
+				j;
+	int			cur_pos = 0;
+	char		mask = 0;
+
+	deconstruct_array_builtin(weights, CHAROID, &dweights, &nulls, &nweights);
+
+	for (i = 0; i < nweights; i++)
+	{
+		char		char_weight;
+
+		if (nulls[i])
+			ereport(ERROR,
+					(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+					 errmsg("weight array may not contain nulls")));
+
+		char_weight = DatumGetChar(dweights[i]);
+		switch (char_weight)
+		{
+			case 'A':
+			case 'a':
+				mask = mask | 8;
+				break;
+			case 'B':
+			case 'b':
+				mask = mask | 4;
+				break;
+			case 'C':
+			case 'c':
+				mask = mask | 2;
+				break;
+			case 'D':
+			case 'd':
+				mask = mask | 1;
+				break;
+			default:
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+						 errmsg("unrecognized weight: \"%c\"", char_weight)));
+		}
+	}
+
+	tsout = (TSVector) palloc0(VARSIZE(tsin));
+	tsout->size = tsin->size;
+	arrout = ARRPTR(tsout);
+	dataout = STRPTR(tsout);
+
+	for (i = j = 0; i < tsin->size; i++)
+	{
+		WordEntryPosVector *posvin,
+				   *posvout;
+		int			npos = 0;
+		int			k;
+
+		if (!arrin[i].haspos)
+			continue;
+
+		posvin = _POSVECPTR(tsin, arrin + i);
+		posvout = (WordEntryPosVector *)
+			(dataout + SHORTALIGN(cur_pos + arrin[i].len));
+
+		for (k = 0; k < posvin->npos; k++)
+		{
+			if (mask & (1 << WEP_GETWEIGHT(posvin->pos[k])))
+				posvout->pos[npos++] = posvin->pos[k];
+		}
+
+		/* if no satisfactory positions found, skip lexeme */
+		if (!npos)
+			continue;
+
+		arrout[j].haspos = true;
+		arrout[j].len = arrin[i].len;
+		arrout[j].pos = cur_pos;
+
+		memcpy(dataout + cur_pos, datain + arrin[i].pos, arrin[i].len);
+		posvout->npos = npos;
+		cur_pos += SHORTALIGN(arrin[i].len);
+		cur_pos += POSDATALEN(tsout, arrout + j) * sizeof(WordEntryPos) +
+			sizeof(uint16);
+		j++;
+	}
+
+	tsout->size = j;
+	if (dataout != STRPTR(tsout))
+		memmove(STRPTR(tsout), dataout, cur_pos);
+
+	SET_VARSIZE(tsout, CALCDATASIZE(tsout->size, cur_pos));
+
+	PG_FREE_IF_COPY(tsin, 0);
+	PG_RETURN_POINTER(tsout);
+}
+
+Datum
+tsvector_concat(PG_FUNCTION_ARGS)
+{
+	TSVector	in1 = PG_GETARG_TSVECTOR(0);
+	TSVector	in2 = PG_GETARG_TSVECTOR(1);
+	TSVector	out;
+	WordEntry  *ptr;
+	WordEntry  *ptr1,
+			   *ptr2;
+	WordEntryPos *p;
+	int			maxpos = 0,
+				i,
+				j,
+				i1,
+				i2,
+				dataoff,
+				output_bytes,
+				output_size;
+	char	   *data,
+			   *data1,
+			   *data2;
+
+	/* Get max position in in1; we'll need this to offset in2's positions */
+	ptr = ARRPTR(in1);
+	i = in1->size;
+	while (i--)
+	{
+		if ((j = POSDATALEN(in1, ptr)) != 0)
+		{
+			p = POSDATAPTR(in1, ptr);
+			while (j--)
+			{
+				if (WEP_GETPOS(*p) > maxpos)
+					maxpos = WEP_GETPOS(*p);
+				p++;
+			}
+		}
+		ptr++;
+	}
+
+	ptr1 = ARRPTR(in1);
+	ptr2 = ARRPTR(in2);
+	data1 = STRPTR(in1);
+	data2 = STRPTR(in2);
+	i1 = in1->size;
+	i2 = in2->size;
+
+	/*
+	 * Conservative estimate of space needed.  We might need all the data in
+	 * both inputs, and conceivably add a pad byte before position data for
+	 * each item where there was none before.
+	 */
+	output_bytes = VARSIZE(in1) + VARSIZE(in2) + i1 + i2;
+
+	out = (TSVector) palloc0(output_bytes);
+	SET_VARSIZE(out, output_bytes);
+
+	/*
+	 * We must make out->size valid so that STRPTR(out) is sensible.  We'll
+	 * collapse out any unused space at the end.
+	 */
+	out->size = in1->size + in2->size;
+
+	ptr = ARRPTR(out);
+	data = STRPTR(out);
+	dataoff = 0;
+	while (i1 && i2)
+	{
+		int			cmp = compareEntry(data1, ptr1, data2, ptr2);
+
+		if (cmp < 0)
+		{						/* in1 first */
+			ptr->haspos = ptr1->haspos;
+			ptr->len = ptr1->len;
+			memcpy(data + dataoff, data1 + ptr1->pos, ptr1->len);
+			ptr->pos = dataoff;
+			dataoff += ptr1->len;
+			if (ptr->haspos)
+			{
+				dataoff = SHORTALIGN(dataoff);
+				memcpy(data + dataoff, _POSVECPTR(in1, ptr1), POSDATALEN(in1, ptr1) * sizeof(WordEntryPos) + sizeof(uint16));
+				dataoff += POSDATALEN(in1, ptr1) * sizeof(WordEntryPos) + sizeof(uint16);
+			}
+
+			ptr++;
+			ptr1++;
+			i1--;
+		}
+		else if (cmp > 0)
+		{						/* in2 first */
+			ptr->haspos = ptr2->haspos;
+			ptr->len = ptr2->len;
+			memcpy(data + dataoff, data2 + ptr2->pos, ptr2->len);
+			ptr->pos = dataoff;
+			dataoff += ptr2->len;
+			if (ptr->haspos)
+			{
+				int			addlen = add_pos(in2, ptr2, out, ptr, maxpos);
+
+				if (addlen == 0)
+					ptr->haspos = 0;
+				else
+				{
+					dataoff = SHORTALIGN(dataoff);
+					dataoff += addlen * sizeof(WordEntryPos) + sizeof(uint16);
+				}
+			}
+
+			ptr++;
+			ptr2++;
+			i2--;
+		}
+		else
+		{
+			ptr->haspos = ptr1->haspos | ptr2->haspos;
+			ptr->len = ptr1->len;
+			memcpy(data + dataoff, data1 + ptr1->pos, ptr1->len);
+			ptr->pos = dataoff;
+			dataoff += ptr1->len;
+			if (ptr->haspos)
+			{
+				if (ptr1->haspos)
+				{
+					dataoff = SHORTALIGN(dataoff);
+					memcpy(data + dataoff, _POSVECPTR(in1, ptr1), POSDATALEN(in1, ptr1) * sizeof(WordEntryPos) + sizeof(uint16));
+					dataoff += POSDATALEN(in1, ptr1) * sizeof(WordEntryPos) + sizeof(uint16);
+					if (ptr2->haspos)
+						dataoff += add_pos(in2, ptr2, out, ptr, maxpos) * sizeof(WordEntryPos);
+				}
+				else			/* must have ptr2->haspos */
+				{
+					int			addlen = add_pos(in2, ptr2, out, ptr, maxpos);
+
+					if (addlen == 0)
+						ptr->haspos = 0;
+					else
+					{
+						dataoff = SHORTALIGN(dataoff);
+						dataoff += addlen * sizeof(WordEntryPos) + sizeof(uint16);
+					}
+				}
+			}
+
+			ptr++;
+			ptr1++;
+			ptr2++;
+			i1--;
+			i2--;
+		}
+	}
+
+	while (i1)
+	{
+		ptr->haspos = ptr1->haspos;
+		ptr->len = ptr1->len;
+		memcpy(data + dataoff, data1 + ptr1->pos, ptr1->len);
+		ptr->pos = dataoff;
+		dataoff += ptr1->len;
+		if (ptr->haspos)
+		{
+			dataoff = SHORTALIGN(dataoff);
+			memcpy(data + dataoff, _POSVECPTR(in1, ptr1), POSDATALEN(in1, ptr1) * sizeof(WordEntryPos) + sizeof(uint16));
+			dataoff += POSDATALEN(in1, ptr1) * sizeof(WordEntryPos) + sizeof(uint16);
+		}
+
+		ptr++;
+		ptr1++;
+		i1--;
+	}
+
+	while (i2)
+	{
+		ptr->haspos = ptr2->haspos;
+		ptr->len = ptr2->len;
+		memcpy(data + dataoff, data2 + ptr2->pos, ptr2->len);
+		ptr->pos = dataoff;
+		dataoff += ptr2->len;
+		if (ptr->haspos)
+		{
+			int			addlen = add_pos(in2, ptr2, out, ptr, maxpos);
+
+			if (addlen == 0)
+				ptr->haspos = 0;
+			else
+			{
+				dataoff = SHORTALIGN(dataoff);
+				dataoff += addlen * sizeof(WordEntryPos) + sizeof(uint16);
+			}
+		}
+
+		ptr++;
+		ptr2++;
+		i2--;
+	}
+
+	/*
+	 * Instead of checking each offset individually, we check for overflow of
+	 * pos fields once at the end.
+	 */
+	if (dataoff > MAXSTRPOS)
+		ereport(ERROR,
+				(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+				 errmsg("string is too long for tsvector (%d bytes, max %d bytes)", dataoff, MAXSTRPOS)));
+
+	/*
+	 * Adjust sizes (asserting that we didn't overrun the original estimates)
+	 * and collapse out any unused array entries.
+	 */
+	output_size = ptr - ARRPTR(out);
+	Assert(output_size <= out->size);
+	out->size = output_size;
+	if (data != STRPTR(out))
+		memmove(STRPTR(out), data, dataoff);
+	output_bytes = CALCDATASIZE(out->size, dataoff);
+	Assert(output_bytes <= VARSIZE(out));
+	SET_VARSIZE(out, output_bytes);
+
+	PG_FREE_IF_COPY(in1, 0);
+	PG_FREE_IF_COPY(in2, 1);
+	PG_RETURN_POINTER(out);
+}
+
+/*
+ * Compare two strings by tsvector rules.
+ *
+ * if prefix = true then it returns zero value iff b has prefix a
+ */
+int32
+tsCompareString(char *a, int lena, char *b, int lenb, bool prefix)
+{
+	int			cmp;
+
+	if (lena == 0)
+	{
+		if (prefix)
+			cmp = 0;			/* empty string is prefix of anything */
+		else
+			cmp = (lenb > 0) ? -1 : 0;
+	}
+	else if (lenb == 0)
+	{
+		cmp = (lena > 0) ? 1 : 0;
+	}
+	else
+	{
+		cmp = memcmp(a, b, Min((unsigned int) lena, (unsigned int) lenb));
+
+		if (prefix)
+		{
+			if (cmp == 0 && lena > lenb)
+				cmp = 1;		/* a is longer, so not a prefix of b */
+		}
+		else if (cmp == 0 && lena != lenb)
+		{
+			cmp = (lena < lenb) ? -1 : 1;
+		}
+	}
+
+	return cmp;
+}
+
+/*
+ * Check weight info or/and fill 'data' with the required positions
+ */
+static TSTernaryValue
+checkclass_str(CHKVAL *chkval, WordEntry *entry, QueryOperand *val,
+			   ExecPhraseData *data)
+{
+	TSTernaryValue result = TS_NO;
+
+	Assert(data == NULL || data->npos == 0);
+
+	if (entry->haspos)
+	{
+		WordEntryPosVector *posvec;
+
+		/*
+		 * We can't use the _POSVECPTR macro here because the pointer to the
+		 * tsvector's lexeme storage is already contained in chkval->values.
+		 */
+		posvec = (WordEntryPosVector *)
+			(chkval->values + SHORTALIGN(entry->pos + entry->len));
+
+		if (val->weight && data)
+		{
+			WordEntryPos *posvec_iter = posvec->pos;
+			WordEntryPos *dptr;
+
+			/*
+			 * Filter position information by weights
+			 */
+			dptr = data->pos = palloc(sizeof(WordEntryPos) * posvec->npos);
+			data->allocated = true;
+
+			/* Is there a position with a matching weight? */
+			while (posvec_iter < posvec->pos + posvec->npos)
+			{
+				/* If true, append this position to the data->pos */
+				if (val->weight & (1 << WEP_GETWEIGHT(*posvec_iter)))
+				{
+					*dptr = WEP_GETPOS(*posvec_iter);
+					dptr++;
+				}
+
+				posvec_iter++;
+			}
+
+			data->npos = dptr - data->pos;
+
+			if (data->npos > 0)
+				result = TS_YES;
+			else
+			{
+				pfree(data->pos);
+				data->pos = NULL;
+				data->allocated = false;
+			}
+		}
+		else if (val->weight)
+		{
+			WordEntryPos *posvec_iter = posvec->pos;
+
+			/* Is there a position with a matching weight? */
+			while (posvec_iter < posvec->pos + posvec->npos)
+			{
+				if (val->weight & (1 << WEP_GETWEIGHT(*posvec_iter)))
+				{
+					result = TS_YES;
+					break;		/* no need to go further */
+				}
+
+				posvec_iter++;
+			}
+		}
+		else if (data)
+		{
+			data->npos = posvec->npos;
+			data->pos = posvec->pos;
+			data->allocated = false;
+			result = TS_YES;
+		}
+		else
+		{
+			/* simplest case: no weight check, positions not needed */
+			result = TS_YES;
+		}
+	}
+	else
+	{
+		/*
+		 * Position info is lacking, so if the caller requires it, we can only
+		 * say that maybe there is a match.
+		 *
+		 * Notice, however, that we *don't* check val->weight here.
+		 * Historically, stripped tsvectors are considered to match queries
+		 * whether or not the query has a weight restriction; that's a little
+		 * dubious but we'll preserve the behavior.
+		 */
+		if (data)
+			result = TS_MAYBE;
+		else
+			result = TS_YES;
+	}
+
+	return result;
+}
+
+/*
+ * TS_execute callback for matching a tsquery operand to plain tsvector data
+ */
+static TSTernaryValue
+checkcondition_str(void *checkval, QueryOperand *val, ExecPhraseData *data)
+{
+	CHKVAL	   *chkval = (CHKVAL *) checkval;
+	WordEntry  *StopLow = chkval->arrb;
+	WordEntry  *StopHigh = chkval->arre;
+	WordEntry  *StopMiddle = StopHigh;
+	TSTernaryValue res = TS_NO;
+
+	/* Loop invariant: StopLow <= val < StopHigh */
+	while (StopLow < StopHigh)
+	{
+		int			difference;
+
+		StopMiddle = StopLow + (StopHigh - StopLow) / 2;
+		difference = tsCompareString(chkval->operand + val->distance,
+									 val->length,
+									 chkval->values + StopMiddle->pos,
+									 StopMiddle->len,
+									 false);
+
+		if (difference == 0)
+		{
+			/* Check weight info & fill 'data' with positions */
+			res = checkclass_str(chkval, StopMiddle, val, data);
+			break;
+		}
+		else if (difference > 0)
+			StopLow = StopMiddle + 1;
+		else
+			StopHigh = StopMiddle;
+	}
+
+	/*
+	 * If it's a prefix search, we should also consider lexemes that the
+	 * search term is a prefix of (which will necessarily immediately follow
+	 * the place we found in the above loop).  But we can skip them if there
+	 * was a definite match on the exact term AND the caller doesn't need
+	 * position info.
+	 */
+	if (val->prefix && (res != TS_YES || data))
+	{
+		WordEntryPos *allpos = NULL;
+		int			npos = 0,
+					totalpos = 0;
+
+		/* adjust start position for corner case */
+		if (StopLow >= StopHigh)
+			StopMiddle = StopHigh;
+
+		/* we don't try to re-use any data from the initial match */
+		if (data)
+		{
+			if (data->allocated)
+				pfree(data->pos);
+			data->pos = NULL;
+			data->allocated = false;
+			data->npos = 0;
+		}
+		res = TS_NO;
+
+		while ((res != TS_YES || data) &&
+			   StopMiddle < chkval->arre &&
+			   tsCompareString(chkval->operand + val->distance,
+							   val->length,
+							   chkval->values + StopMiddle->pos,
+							   StopMiddle->len,
+							   true) == 0)
+		{
+			TSTernaryValue subres;
+
+			subres = checkclass_str(chkval, StopMiddle, val, data);
+
+			if (subres != TS_NO)
+			{
+				if (data)
+				{
+					/*
+					 * We need to join position information
+					 */
+					if (subres == TS_MAYBE)
+					{
+						/*
+						 * No position info for this match, so we must report
+						 * MAYBE overall.
+						 */
+						res = TS_MAYBE;
+						/* forget any previous positions */
+						npos = 0;
+						/* don't leak storage */
+						if (allpos)
+							pfree(allpos);
+						break;
+					}
+
+					while (npos + data->npos > totalpos)
+					{
+						if (totalpos == 0)
+						{
+							totalpos = 256;
+							allpos = palloc(sizeof(WordEntryPos) * totalpos);
+						}
+						else
+						{
+							totalpos *= 2;
+							allpos = repalloc(allpos, sizeof(WordEntryPos) * totalpos);
+						}
+					}
+
+					memcpy(allpos + npos, data->pos, sizeof(WordEntryPos) * data->npos);
+					npos += data->npos;
+
+					/* don't leak storage from individual matches */
+					if (data->allocated)
+						pfree(data->pos);
+					data->pos = NULL;
+					data->allocated = false;
+					/* it's important to reset data->npos before next loop */
+					data->npos = 0;
+				}
+				else
+				{
+					/* Don't need positions, just handle YES/MAYBE */
+					if (subres == TS_YES || res == TS_NO)
+						res = subres;
+				}
+			}
+
+			StopMiddle++;
+		}
+
+		if (data && npos > 0)
+		{
+			/* Sort and make unique array of found positions */
+			data->pos = allpos;
+			qsort(data->pos, npos, sizeof(WordEntryPos), compareWordEntryPos);
+			data->npos = qunique(data->pos, npos, sizeof(WordEntryPos),
+								 compareWordEntryPos);
+			data->allocated = true;
+			res = TS_YES;
+		}
+	}
+
+	return res;
+}
+
+/*
+ * Compute output position list for a tsquery operator in phrase mode.
+ *
+ * Merge the position lists in Ldata and Rdata as specified by "emit",
+ * returning the result list into *data.  The input position lists must be
+ * sorted and unique, and the output will be as well.
+ *
+ * data: pointer to initially-all-zeroes output struct, or NULL
+ * Ldata, Rdata: input position lists
+ * emit: bitmask of TSPO_XXX flags
+ * Loffset: offset to be added to Ldata positions before comparing/outputting
+ * Roffset: offset to be added to Rdata positions before comparing/outputting
+ * max_npos: maximum possible required size of output position array
+ *
+ * Loffset and Roffset should not be negative, else we risk trying to output
+ * negative positions, which won't fit into WordEntryPos.
+ *
+ * The result is boolean (TS_YES or TS_NO), but for the caller's convenience
+ * we return it as TSTernaryValue.
+ *
+ * Returns TS_YES if any positions were emitted to *data; or if data is NULL,
+ * returns TS_YES if any positions would have been emitted.
+ */
+#define TSPO_L_ONLY		0x01	/* emit positions appearing only in L */
+#define TSPO_R_ONLY		0x02	/* emit positions appearing only in R */
+#define TSPO_BOTH		0x04	/* emit positions appearing in both L&R */
+
+static TSTernaryValue
+TS_phrase_output(ExecPhraseData *data,
+				 ExecPhraseData *Ldata,
+				 ExecPhraseData *Rdata,
+				 int emit,
+				 int Loffset,
+				 int Roffset,
+				 int max_npos)
+{
+	int			Lindex,
+				Rindex;
+
+	/* Loop until both inputs are exhausted */
+	Lindex = Rindex = 0;
+	while (Lindex < Ldata->npos || Rindex < Rdata->npos)
+	{
+		int			Lpos,
+					Rpos;
+		int			output_pos = 0;
+
+		/*
+		 * Fetch current values to compare.  WEP_GETPOS() is needed because
+		 * ExecPhraseData->data can point to a tsvector's WordEntryPosVector.
+		 */
+		if (Lindex < Ldata->npos)
+			Lpos = WEP_GETPOS(Ldata->pos[Lindex]) + Loffset;
+		else
+		{
+			/* L array exhausted, so we're done if R_ONLY isn't set */
+			if (!(emit & TSPO_R_ONLY))
+				break;
+			Lpos = INT_MAX;
+		}
+		if (Rindex < Rdata->npos)
+			Rpos = WEP_GETPOS(Rdata->pos[Rindex]) + Roffset;
+		else
+		{
+			/* R array exhausted, so we're done if L_ONLY isn't set */
+			if (!(emit & TSPO_L_ONLY))
+				break;
+			Rpos = INT_MAX;
+		}
+
+		/* Merge-join the two input lists */
+		if (Lpos < Rpos)
+		{
+			/* Lpos is not matched in Rdata, should we output it? */
+			if (emit & TSPO_L_ONLY)
+				output_pos = Lpos;
+			Lindex++;
+		}
+		else if (Lpos == Rpos)
+		{
+			/* Lpos and Rpos match ... should we output it? */
+			if (emit & TSPO_BOTH)
+				output_pos = Rpos;
+			Lindex++;
+			Rindex++;
+		}
+		else					/* Lpos > Rpos */
+		{
+			/* Rpos is not matched in Ldata, should we output it? */
+			if (emit & TSPO_R_ONLY)
+				output_pos = Rpos;
+			Rindex++;
+		}
+
+		if (output_pos > 0)
+		{
+			if (data)
+			{
+				/* Store position, first allocating output array if needed */
+				if (data->pos == NULL)
+				{
+					data->pos = (WordEntryPos *)
+						palloc(max_npos * sizeof(WordEntryPos));
+					data->allocated = true;
+				}
+				data->pos[data->npos++] = output_pos;
+			}
+			else
+			{
+				/*
+				 * Exact positions not needed, so return TS_YES as soon as we
+				 * know there is at least one.
+				 */
+				return TS_YES;
+			}
+		}
+	}
+
+	if (data && data->npos > 0)
+	{
+		/* Let's assert we didn't overrun the array */
+		Assert(data->npos <= max_npos);
+		return TS_YES;
+	}
+	return TS_NO;
+}
+
+/*
+ * Execute tsquery at or below an OP_PHRASE operator.
+ *
+ * This handles tsquery execution at recursion levels where we need to care
+ * about match locations.
+ *
+ * In addition to the same arguments used for TS_execute, the caller may pass
+ * a preinitialized-to-zeroes ExecPhraseData struct, to be filled with lexeme
+ * match position info on success.  data == NULL if no position data need be
+ * returned.
+ * Note: the function assumes data != NULL for operators other than OP_PHRASE.
+ * This is OK because an outside call always starts from an OP_PHRASE node,
+ * and all internal recursion cases pass data != NULL.
+ *
+ * The detailed semantics of the match data, given that the function returned
+ * TS_YES (successful match), are:
+ *
+ * npos > 0, negate = false:
+ *	 query is matched at specified position(s) (and only those positions)
+ * npos > 0, negate = true:
+ *	 query is matched at all positions *except* specified position(s)
+ * npos = 0, negate = true:
+ *	 query is matched at all positions
+ * npos = 0, negate = false:
+ *	 disallowed (this should result in TS_NO or TS_MAYBE, as appropriate)
+ *
+ * Successful matches also return a "width" value which is the match width in
+ * lexemes, less one.  Hence, "width" is zero for simple one-lexeme matches,
+ * and is the sum of the phrase operator distances for phrase matches.  Note
+ * that when width > 0, the listed positions represent the ends of matches not
+ * the starts.  (This unintuitive rule is needed to avoid possibly generating
+ * negative positions, which wouldn't fit into the WordEntryPos arrays.)
+ *
+ * If the TSExecuteCallback function reports that an operand is present
+ * but fails to provide position(s) for it, we will return TS_MAYBE when
+ * it is possible but not certain that the query is matched.
+ *
+ * When the function returns TS_NO or TS_MAYBE, it must return npos = 0,
+ * negate = false (which is the state initialized by the caller); but the
+ * "width" output in such cases is undefined.
+ */
+static TSTernaryValue
+TS_phrase_execute(QueryItem *curitem, void *arg, uint32 flags,
+				  TSExecuteCallback chkcond,
+				  ExecPhraseData *data)
+{
+	ExecPhraseData Ldata,
+				Rdata;
+	TSTernaryValue lmatch,
+				rmatch;
+	int			Loffset,
+				Roffset,
+				maxwidth;
+
+	/* since this function recurses, it could be driven to stack overflow */
+	check_stack_depth();
+
+	/* ... and let's check for query cancel while we're at it */
+	CHECK_FOR_INTERRUPTS();
+
+	if (curitem->type == QI_VAL)
+		return chkcond(arg, (QueryOperand *) curitem, data);
+
+	switch (curitem->qoperator.oper)
+	{
+		case OP_NOT:
+
+			/*
+			 * We need not touch data->width, since a NOT operation does not
+			 * change the match width.
+			 */
+			if (flags & TS_EXEC_SKIP_NOT)
+			{
+				/* with SKIP_NOT, report NOT as "match everywhere" */
+				Assert(data->npos == 0 && !data->negate);
+				data->negate = true;
+				return TS_YES;
+			}
+			switch (TS_phrase_execute(curitem + 1, arg, flags, chkcond, data))
+			{
+				case TS_NO:
+					/* change "match nowhere" to "match everywhere" */
+					Assert(data->npos == 0 && !data->negate);
+					data->negate = true;
+					return TS_YES;
+				case TS_YES:
+					if (data->npos > 0)
+					{
+						/* we have some positions, invert negate flag */
+						data->negate = !data->negate;
+						return TS_YES;
+					}
+					else if (data->negate)
+					{
+						/* change "match everywhere" to "match nowhere" */
+						data->negate = false;
+						return TS_NO;
+					}
+					/* Should not get here if result was TS_YES */
+					Assert(false);
+					break;
+				case TS_MAYBE:
+					/* match positions are, and remain, uncertain */
+					return TS_MAYBE;
+			}
+			break;
+
+		case OP_PHRASE:
+		case OP_AND:
+			memset(&Ldata, 0, sizeof(Ldata));
+			memset(&Rdata, 0, sizeof(Rdata));
+
+			lmatch = TS_phrase_execute(curitem + curitem->qoperator.left,
+									   arg, flags, chkcond, &Ldata);
+			if (lmatch == TS_NO)
+				return TS_NO;
+
+			rmatch = TS_phrase_execute(curitem + 1,
+									   arg, flags, chkcond, &Rdata);
+			if (rmatch == TS_NO)
+				return TS_NO;
+
+			/*
+			 * If either operand has no position information, then we can't
+			 * return reliable position data, only a MAYBE result.
+			 */
+			if (lmatch == TS_MAYBE || rmatch == TS_MAYBE)
+				return TS_MAYBE;
+
+			if (curitem->qoperator.oper == OP_PHRASE)
+			{
+				/*
+				 * Compute Loffset and Roffset suitable for phrase match, and
+				 * compute overall width of whole phrase match.
+				 */
+				Loffset = curitem->qoperator.distance + Rdata.width;
+				Roffset = 0;
+				if (data)
+					data->width = curitem->qoperator.distance +
+						Ldata.width + Rdata.width;
+			}
+			else
+			{
+				/*
+				 * For OP_AND, set output width and alignment like OP_OR (see
+				 * comment below)
+				 */
+				maxwidth = Max(Ldata.width, Rdata.width);
+				Loffset = maxwidth - Ldata.width;
+				Roffset = maxwidth - Rdata.width;
+				if (data)
+					data->width = maxwidth;
+			}
+
+			if (Ldata.negate && Rdata.negate)
+			{
+				/* !L & !R: treat as !(L | R) */
+				(void) TS_phrase_output(data, &Ldata, &Rdata,
+										TSPO_BOTH | TSPO_L_ONLY | TSPO_R_ONLY,
+										Loffset, Roffset,
+										Ldata.npos + Rdata.npos);
+				if (data)
+					data->negate = true;
+				return TS_YES;
+			}
+			else if (Ldata.negate)
+			{
+				/* !L & R */
+				return TS_phrase_output(data, &Ldata, &Rdata,
+										TSPO_R_ONLY,
+										Loffset, Roffset,
+										Rdata.npos);
+			}
+			else if (Rdata.negate)
+			{
+				/* L & !R */
+				return TS_phrase_output(data, &Ldata, &Rdata,
+										TSPO_L_ONLY,
+										Loffset, Roffset,
+										Ldata.npos);
+			}
+			else
+			{
+				/* straight AND */
+				return TS_phrase_output(data, &Ldata, &Rdata,
+										TSPO_BOTH,
+										Loffset, Roffset,
+										Min(Ldata.npos, Rdata.npos));
+			}
+
+		case OP_OR:
+			memset(&Ldata, 0, sizeof(Ldata));
+			memset(&Rdata, 0, sizeof(Rdata));
+
+			lmatch = TS_phrase_execute(curitem + curitem->qoperator.left,
+									   arg, flags, chkcond, &Ldata);
+			rmatch = TS_phrase_execute(curitem + 1,
+									   arg, flags, chkcond, &Rdata);
+
+			if (lmatch == TS_NO && rmatch == TS_NO)
+				return TS_NO;
+
+			/*
+			 * If either operand has no position information, then we can't
+			 * return reliable position data, only a MAYBE result.
+			 */
+			if (lmatch == TS_MAYBE || rmatch == TS_MAYBE)
+				return TS_MAYBE;
+
+			/*
+			 * Cope with undefined output width from failed submatch.  (This
+			 * takes less code than trying to ensure that all failure returns
+			 * set data->width to zero.)
+			 */
+			if (lmatch == TS_NO)
+				Ldata.width = 0;
+			if (rmatch == TS_NO)
+				Rdata.width = 0;
+
+			/*
+			 * For OP_AND and OP_OR, report the width of the wider of the two
+			 * inputs, and align the narrower input's positions to the right
+			 * end of that width.  This rule deals at least somewhat
+			 * reasonably with cases like "x <-> (y | z <-> q)".
+			 */
+			maxwidth = Max(Ldata.width, Rdata.width);
+			Loffset = maxwidth - Ldata.width;
+			Roffset = maxwidth - Rdata.width;
+			data->width = maxwidth;
+
+			if (Ldata.negate && Rdata.negate)
+			{
+				/* !L | !R: treat as !(L & R) */
+				(void) TS_phrase_output(data, &Ldata, &Rdata,
+										TSPO_BOTH,
+										Loffset, Roffset,
+										Min(Ldata.npos, Rdata.npos));
+				data->negate = true;
+				return TS_YES;
+			}
+			else if (Ldata.negate)
+			{
+				/* !L | R: treat as !(L & !R) */
+				(void) TS_phrase_output(data, &Ldata, &Rdata,
+										TSPO_L_ONLY,
+										Loffset, Roffset,
+										Ldata.npos);
+				data->negate = true;
+				return TS_YES;
+			}
+			else if (Rdata.negate)
+			{
+				/* L | !R: treat as !(!L & R) */
+				(void) TS_phrase_output(data, &Ldata, &Rdata,
+										TSPO_R_ONLY,
+										Loffset, Roffset,
+										Rdata.npos);
+				data->negate = true;
+				return TS_YES;
+			}
+			else
+			{
+				/* straight OR */
+				return TS_phrase_output(data, &Ldata, &Rdata,
+										TSPO_BOTH | TSPO_L_ONLY | TSPO_R_ONLY,
+										Loffset, Roffset,
+										Ldata.npos + Rdata.npos);
+			}
+
+		default:
+			elog(ERROR, "unrecognized operator: %d", curitem->qoperator.oper);
+	}
+
+	/* not reachable, but keep compiler quiet */
+	return TS_NO;
+}
+
+
+/*
+ * Evaluate tsquery boolean expression.
+ *
+ * curitem: current tsquery item (initially, the first one)
+ * arg: opaque value to pass through to callback function
+ * flags: bitmask of flag bits shown in ts_utils.h
+ * chkcond: callback function to check whether a primitive value is present
+ */
+bool
+TS_execute(QueryItem *curitem, void *arg, uint32 flags,
+		   TSExecuteCallback chkcond)
+{
+	/*
+	 * If we get TS_MAYBE from the recursion, return true.  We could only see
+	 * that result if the caller passed TS_EXEC_PHRASE_NO_POS, so there's no
+	 * need to check again.
+	 */
+	return TS_execute_recurse(curitem, arg, flags, chkcond) != TS_NO;
+}
+
+/*
+ * Evaluate tsquery boolean expression.
+ *
+ * This is the same as TS_execute except that TS_MAYBE is returned as-is.
+ */
+TSTernaryValue
+TS_execute_ternary(QueryItem *curitem, void *arg, uint32 flags,
+				   TSExecuteCallback chkcond)
+{
+	return TS_execute_recurse(curitem, arg, flags, chkcond);
+}
+
+/*
+ * TS_execute recursion for operators above any phrase operator.  Here we do
+ * not need to worry about lexeme positions.  As soon as we hit an OP_PHRASE
+ * operator, we pass it off to TS_phrase_execute which does worry.
+ */
+static TSTernaryValue
+TS_execute_recurse(QueryItem *curitem, void *arg, uint32 flags,
+				   TSExecuteCallback chkcond)
+{
+	TSTernaryValue lmatch;
+
+	/* since this function recurses, it could be driven to stack overflow */
+	check_stack_depth();
+
+	/* ... and let's check for query cancel while we're at it */
+	CHECK_FOR_INTERRUPTS();
+
+	if (curitem->type == QI_VAL)
+		return chkcond(arg, (QueryOperand *) curitem,
+					   NULL /* don't need position info */ );
+
+	switch (curitem->qoperator.oper)
+	{
+		case OP_NOT:
+			if (flags & TS_EXEC_SKIP_NOT)
+				return TS_YES;
+			switch (TS_execute_recurse(curitem + 1, arg, flags, chkcond))
+			{
+				case TS_NO:
+					return TS_YES;
+				case TS_YES:
+					return TS_NO;
+				case TS_MAYBE:
+					return TS_MAYBE;
+			}
+			break;
+
+		case OP_AND:
+			lmatch = TS_execute_recurse(curitem + curitem->qoperator.left, arg,
+										flags, chkcond);
+			if (lmatch == TS_NO)
+				return TS_NO;
+			switch (TS_execute_recurse(curitem + 1, arg, flags, chkcond))
+			{
+				case TS_NO:
+					return TS_NO;
+				case TS_YES:
+					return lmatch;
+				case TS_MAYBE:
+					return TS_MAYBE;
+			}
+			break;
+
+		case OP_OR:
+			lmatch = TS_execute_recurse(curitem + curitem->qoperator.left, arg,
+										flags, chkcond);
+			if (lmatch == TS_YES)
+				return TS_YES;
+			switch (TS_execute_recurse(curitem + 1, arg, flags, chkcond))
+			{
+				case TS_NO:
+					return lmatch;
+				case TS_YES:
+					return TS_YES;
+				case TS_MAYBE:
+					return TS_MAYBE;
+			}
+			break;
+
+		case OP_PHRASE:
+
+			/*
+			 * If we get a MAYBE result, and the caller doesn't want that,
+			 * convert it to NO.  It would be more consistent, perhaps, to
+			 * return the result of TS_phrase_execute() verbatim and then
+			 * convert MAYBE results at the top of the recursion.  But
+			 * converting at the topmost phrase operator gives results that
+			 * are bug-compatible with the old implementation, so do it like
+			 * this for now.
+			 */
+			switch (TS_phrase_execute(curitem, arg, flags, chkcond, NULL))
+			{
+				case TS_NO:
+					return TS_NO;
+				case TS_YES:
+					return TS_YES;
+				case TS_MAYBE:
+					return (flags & TS_EXEC_PHRASE_NO_POS) ? TS_MAYBE : TS_NO;
+			}
+			break;
+
+		default:
+			elog(ERROR, "unrecognized operator: %d", curitem->qoperator.oper);
+	}
+
+	/* not reachable, but keep compiler quiet */
+	return TS_NO;
+}
+
+/*
+ * Evaluate tsquery and report locations of matching terms.
+ *
+ * This is like TS_execute except that it returns match locations not just
+ * success/failure status.  The callback function is required to provide
+ * position data (we report failure if it doesn't).
+ *
+ * On successful match, the result is a List of ExecPhraseData structs, one
+ * for each AND'ed term or phrase operator in the query.  Each struct includes
+ * a sorted array of lexeme positions matching that term.  (Recall that for
+ * phrase operators, the match includes width+1 lexemes, and the recorded
+ * position is that of the rightmost lexeme.)
+ *
+ * OR subexpressions are handled by union'ing their match locations into a
+ * single List element, which is valid since any of those locations contains
+ * a match.  However, when some of the OR'ed terms are phrase operators, we
+ * report the maximum width of any of the OR'ed terms, making such cases
+ * slightly imprecise in the conservative direction.  (For example, if the
+ * tsquery is "(A <-> B) | C", an occurrence of C in the data would be
+ * reported as though it includes the lexeme to the left of C.)
+ *
+ * Locations of NOT subexpressions are not reported.  (Obviously, there can
+ * be no successful NOT matches at top level, or the match would have failed.
+ * So this amounts to ignoring NOTs underneath ORs.)
+ *
+ * The result is NIL if no match, or if position data was not returned.
+ *
+ * Arguments are the same as for TS_execute, although flags is currently
+ * vestigial since none of the defined bits are sensible here.
+ */
+List *
+TS_execute_locations(QueryItem *curitem, void *arg,
+					 uint32 flags,
+					 TSExecuteCallback chkcond)
+{
+	List	   *result;
+
+	/* No flags supported, as yet */
+	Assert(flags == TS_EXEC_EMPTY);
+	if (TS_execute_locations_recurse(curitem, arg, chkcond, &result))
+		return result;
+	return NIL;
+}
+
+/*
+ * TS_execute_locations recursion for operators above any phrase operator.
+ * OP_PHRASE subexpressions can be passed off to TS_phrase_execute.
+ */
+static bool
+TS_execute_locations_recurse(QueryItem *curitem, void *arg,
+							 TSExecuteCallback chkcond,
+							 List **locations)
+{
+	bool		lmatch,
+				rmatch;
+	List	   *llocations,
+			   *rlocations;
+	ExecPhraseData *data;
+
+	/* since this function recurses, it could be driven to stack overflow */
+	check_stack_depth();
+
+	/* ... and let's check for query cancel while we're at it */
+	CHECK_FOR_INTERRUPTS();
+
+	/* Default locations result is empty */
+	*locations = NIL;
+
+	if (curitem->type == QI_VAL)
+	{
+		data = palloc0_object(ExecPhraseData);
+		if (chkcond(arg, (QueryOperand *) curitem, data) == TS_YES)
+		{
+			*locations = list_make1(data);
+			return true;
+		}
+		pfree(data);
+		return false;
+	}
+
+	switch (curitem->qoperator.oper)
+	{
+		case OP_NOT:
+			if (!TS_execute_locations_recurse(curitem + 1, arg, chkcond,
+											  &llocations))
+				return true;	/* we don't pass back any locations */
+			return false;
+
+		case OP_AND:
+			if (!TS_execute_locations_recurse(curitem + curitem->qoperator.left,
+											  arg, chkcond,
+											  &llocations))
+				return false;
+			if (!TS_execute_locations_recurse(curitem + 1,
+											  arg, chkcond,
+											  &rlocations))
+				return false;
+			*locations = list_concat(llocations, rlocations);
+			return true;
+
+		case OP_OR:
+			lmatch = TS_execute_locations_recurse(curitem + curitem->qoperator.left,
+												  arg, chkcond,
+												  &llocations);
+			rmatch = TS_execute_locations_recurse(curitem + 1,
+												  arg, chkcond,
+												  &rlocations);
+			if (lmatch || rmatch)
+			{
+				/*
+				 * We generate an AND'able location struct from each
+				 * combination of sub-matches, following the disjunctive law
+				 * (A & B) | (C & D) = (A | C) & (A | D) & (B | C) & (B | D).
+				 *
+				 * However, if either input didn't produce locations (i.e., it
+				 * failed or was a NOT), we must just return the other list.
+				 */
+				if (llocations == NIL)
+					*locations = rlocations;
+				else if (rlocations == NIL)
+					*locations = llocations;
+				else
+				{
+					ListCell   *ll;
+
+					foreach(ll, llocations)
+					{
+						ExecPhraseData *ldata = (ExecPhraseData *) lfirst(ll);
+						ListCell   *lr;
+
+						foreach(lr, rlocations)
+						{
+							ExecPhraseData *rdata = (ExecPhraseData *) lfirst(lr);
+
+							data = palloc0_object(ExecPhraseData);
+							(void) TS_phrase_output(data, ldata, rdata,
+													TSPO_BOTH | TSPO_L_ONLY | TSPO_R_ONLY,
+													0, 0,
+													ldata->npos + rdata->npos);
+							/* Report the larger width, as explained above. */
+							data->width = Max(ldata->width, rdata->width);
+							*locations = lappend(*locations, data);
+						}
+					}
+				}
+
+				return true;
+			}
+			return false;
+
+		case OP_PHRASE:
+			/* We can hand this off to TS_phrase_execute */
+			data = palloc0_object(ExecPhraseData);
+			if (TS_phrase_execute(curitem, arg, TS_EXEC_EMPTY, chkcond,
+								  data) == TS_YES)
+			{
+				if (!data->negate)
+					*locations = list_make1(data);
+				return true;
+			}
+			pfree(data);
+			return false;
+
+		default:
+			elog(ERROR, "unrecognized operator: %d", curitem->qoperator.oper);
+	}
+
+	/* not reachable, but keep compiler quiet */
+	return false;
+}
+
+/*
+ * Detect whether a tsquery boolean expression requires any positive matches
+ * to values shown in the tsquery.
+ *
+ * This is needed to know whether a GIN index search requires full index scan.
+ * For example, 'x & !y' requires a match of x, so it's sufficient to scan
+ * entries for x; but 'x | !y' could match rows containing neither x nor y.
+ */
+bool
+tsquery_requires_match(QueryItem *curitem)
+{
+	/* since this function recurses, it could be driven to stack overflow */
+	check_stack_depth();
+
+	if (curitem->type == QI_VAL)
+		return true;
+
+	switch (curitem->qoperator.oper)
+	{
+		case OP_NOT:
+
+			/*
+			 * Assume there are no required matches underneath a NOT.  For
+			 * some cases with nested NOTs, we could prove there's a required
+			 * match, but it seems unlikely to be worth the trouble.
+			 */
+			return false;
+
+		case OP_PHRASE:
+
+			/*
+			 * Treat OP_PHRASE as OP_AND here
+			 */
+		case OP_AND:
+			/* If either side requires a match, we're good */
+			if (tsquery_requires_match(curitem + curitem->qoperator.left))
+				return true;
+			else
+				return tsquery_requires_match(curitem + 1);
+
+		case OP_OR:
+			/* Both sides must require a match */
+			if (tsquery_requires_match(curitem + curitem->qoperator.left))
+				return tsquery_requires_match(curitem + 1);
+			else
+				return false;
+
+		default:
+			elog(ERROR, "unrecognized operator: %d", curitem->qoperator.oper);
+	}
+
+	/* not reachable, but keep compiler quiet */
+	return false;
+}
+
+/*
+ * boolean operations
+ */
+Datum
+ts_match_qv(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_DATUM(DirectFunctionCall2(ts_match_vq,
+										PG_GETARG_DATUM(1),
+										PG_GETARG_DATUM(0)));
+}
+
+Datum
+ts_match_vq(PG_FUNCTION_ARGS)
+{
+	TSVector	val = PG_GETARG_TSVECTOR(0);
+	TSQuery		query = PG_GETARG_TSQUERY(1);
+	CHKVAL		chkval;
+	bool		result;
+
+	/* empty query matches nothing */
+	if (!query->size)
+	{
+		PG_FREE_IF_COPY(val, 0);
+		PG_FREE_IF_COPY(query, 1);
+		PG_RETURN_BOOL(false);
+	}
+
+	chkval.arrb = ARRPTR(val);
+	chkval.arre = chkval.arrb + val->size;
+	chkval.values = STRPTR(val);
+	chkval.operand = GETOPERAND(query);
+	result = TS_execute(GETQUERY(query),
+						&chkval,
+						TS_EXEC_EMPTY,
+						checkcondition_str);
+
+	PG_FREE_IF_COPY(val, 0);
+	PG_FREE_IF_COPY(query, 1);
+	PG_RETURN_BOOL(result);
+}
+
+Datum
+ts_match_tt(PG_FUNCTION_ARGS)
+{
+	TSVector	vector;
+	TSQuery		query;
+	bool		res;
+
+	vector = DatumGetTSVector(DirectFunctionCall1(to_tsvector,
+												  PG_GETARG_DATUM(0)));
+	query = DatumGetTSQuery(DirectFunctionCall1(plainto_tsquery,
+												PG_GETARG_DATUM(1)));
+
+	res = DatumGetBool(DirectFunctionCall2(ts_match_vq,
+										   TSVectorGetDatum(vector),
+										   TSQueryGetDatum(query)));
+
+	pfree(vector);
+	pfree(query);
+
+	PG_RETURN_BOOL(res);
+}
+
+Datum
+ts_match_tq(PG_FUNCTION_ARGS)
+{
+	TSVector	vector;
+	TSQuery		query = PG_GETARG_TSQUERY(1);
+	bool		res;
+
+	vector = DatumGetTSVector(DirectFunctionCall1(to_tsvector,
+												  PG_GETARG_DATUM(0)));
+
+	res = DatumGetBool(DirectFunctionCall2(ts_match_vq,
+										   TSVectorGetDatum(vector),
+										   TSQueryGetDatum(query)));
+
+	pfree(vector);
+	PG_FREE_IF_COPY(query, 1);
+
+	PG_RETURN_BOOL(res);
+}
+
+/*
+ * ts_stat statistic function support
+ */
+
+
+/*
+ * Returns the number of positions in value 'wptr' within tsvector 'txt',
+ * that have a weight equal to one of the weights in 'weight' bitmask.
+ */
+static int
+check_weight(TSVector txt, WordEntry *wptr, int8 weight)
+{
+	int			len = POSDATALEN(txt, wptr);
+	int			num = 0;
+	WordEntryPos *ptr = POSDATAPTR(txt, wptr);
+
+	while (len--)
+	{
+		if (weight & (1 << WEP_GETWEIGHT(*ptr)))
+			num++;
+		ptr++;
+	}
+	return num;
+}
+
+#define compareStatWord(a,e,t)							\
+	tsCompareString((a)->lexeme, (a)->lenlexeme,		\
+					STRPTR(t) + (e)->pos, (e)->len,		\
+					false)
+
+static void
+insertStatEntry(MemoryContext persistentContext, TSVectorStat *stat, TSVector txt, uint32 off)
+{
+	WordEntry  *we = ARRPTR(txt) + off;
+	StatEntry  *node = stat->root,
+			   *pnode = NULL;
+	int			n,
+				res = 0;
+	uint32		depth = 1;
+
+	if (stat->weight == 0)
+		n = (we->haspos) ? POSDATALEN(txt, we) : 1;
+	else
+		n = (we->haspos) ? check_weight(txt, we, stat->weight) : 0;
+
+	if (n == 0)
+		return;					/* nothing to insert */
+
+	while (node)
+	{
+		res = compareStatWord(node, we, txt);
+
+		if (res == 0)
+		{
+			break;
+		}
+		else
+		{
+			pnode = node;
+			node = (res < 0) ? node->left : node->right;
+		}
+		depth++;
+	}
+
+	if (depth > stat->maxdepth)
+		stat->maxdepth = depth;
+
+	if (node == NULL)
+	{
+		node = MemoryContextAlloc(persistentContext, STATENTRYHDRSZ + we->len);
+		node->left = node->right = NULL;
+		node->ndoc = 1;
+		node->nentry = n;
+		node->lenlexeme = we->len;
+		memcpy(node->lexeme, STRPTR(txt) + we->pos, node->lenlexeme);
+
+		if (pnode == NULL)
+		{
+			stat->root = node;
+		}
+		else
+		{
+			if (res < 0)
+				pnode->left = node;
+			else
+				pnode->right = node;
+		}
+	}
+	else
+	{
+		node->ndoc++;
+		node->nentry += n;
+	}
+}
+
+static void
+chooseNextStatEntry(MemoryContext persistentContext, TSVectorStat *stat, TSVector txt,
+					uint32 low, uint32 high, uint32 offset)
+{
+	uint32		pos;
+	uint32		middle = (low + high) >> 1;
+
+	pos = (low + middle) >> 1;
+	if (low != middle && pos >= offset && pos - offset < txt->size)
+		insertStatEntry(persistentContext, stat, txt, pos - offset);
+	pos = (high + middle + 1) >> 1;
+	if (middle + 1 != high && pos >= offset && pos - offset < txt->size)
+		insertStatEntry(persistentContext, stat, txt, pos - offset);
+
+	if (low != middle)
+		chooseNextStatEntry(persistentContext, stat, txt, low, middle, offset);
+	if (high != middle + 1)
+		chooseNextStatEntry(persistentContext, stat, txt, middle + 1, high, offset);
+}
+
+/*
+ * This is written like a custom aggregate function, because the
+ * original plan was to do just that. Unfortunately, an aggregate function
+ * can't return a set, so that plan was abandoned. If that limitation is
+ * lifted in the future, ts_stat could be a real aggregate function so that
+ * you could use it like this:
+ *
+ *	 SELECT ts_stat(vector_column) FROM vector_table;
+ *
+ *	where vector_column is a tsvector-type column in vector_table.
+ */
+
+static TSVectorStat *
+ts_accum(MemoryContext persistentContext, TSVectorStat *stat, Datum data)
+{
+	TSVector	txt = DatumGetTSVector(data);
+	uint32		i,
+				nbit = 0,
+				offset;
+
+	if (stat == NULL)
+	{							/* Init in first */
+		stat = MemoryContextAllocZero(persistentContext, sizeof(TSVectorStat));
+		stat->maxdepth = 1;
+	}
+
+	/* simple check of correctness */
+	if (txt == NULL || txt->size == 0)
+	{
+		if (txt && txt != (TSVector) DatumGetPointer(data))
+			pfree(txt);
+		return stat;
+	}
+
+	i = txt->size - 1;
+	for (; i > 0; i >>= 1)
+		nbit++;
+
+	nbit = 1 << nbit;
+	offset = (nbit - txt->size) / 2;
+
+	insertStatEntry(persistentContext, stat, txt, (nbit >> 1) - offset);
+	chooseNextStatEntry(persistentContext, stat, txt, 0, nbit, offset);
+
+	return stat;
+}
+
+static void
+ts_setup_firstcall(FunctionCallInfo fcinfo, FuncCallContext *funcctx,
+				   TSVectorStat *stat)
+{
+	TupleDesc	tupdesc;
+	MemoryContext oldcontext;
+	StatEntry  *node;
+
+	funcctx->user_fctx = (void *) stat;
+
+	oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
+
+	stat->stack = palloc0(sizeof(StatEntry *) * (stat->maxdepth + 1));
+	stat->stackpos = 0;
+
+	node = stat->root;
+	/* find leftmost value */
+	if (node == NULL)
+		stat->stack[stat->stackpos] = NULL;
+	else
+		for (;;)
+		{
+			stat->stack[stat->stackpos] = node;
+			if (node->left)
+			{
+				stat->stackpos++;
+				node = node->left;
+			}
+			else
+				break;
+		}
+	Assert(stat->stackpos <= stat->maxdepth);
+
+	if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
+		elog(ERROR, "return type must be a row type");
+	funcctx->tuple_desc = tupdesc;
+	funcctx->attinmeta = TupleDescGetAttInMetadata(tupdesc);
+
+	MemoryContextSwitchTo(oldcontext);
+}
+
+static StatEntry *
+walkStatEntryTree(TSVectorStat *stat)
+{
+	StatEntry  *node = stat->stack[stat->stackpos];
+
+	if (node == NULL)
+		return NULL;
+
+	if (node->ndoc != 0)
+	{
+		/* return entry itself: we already was at left sublink */
+		return node;
+	}
+	else if (node->right && node->right != stat->stack[stat->stackpos + 1])
+	{
+		/* go on right sublink */
+		stat->stackpos++;
+		node = node->right;
+
+		/* find most-left value */
+		for (;;)
+		{
+			stat->stack[stat->stackpos] = node;
+			if (node->left)
+			{
+				stat->stackpos++;
+				node = node->left;
+			}
+			else
+				break;
+		}
+		Assert(stat->stackpos <= stat->maxdepth);
+	}
+	else
+	{
+		/* we already return all left subtree, itself and  right subtree */
+		if (stat->stackpos == 0)
+			return NULL;
+
+		stat->stackpos--;
+		return walkStatEntryTree(stat);
+	}
+
+	return node;
+}
+
+static Datum
+ts_process_call(FuncCallContext *funcctx)
+{
+	TSVectorStat *st;
+	StatEntry  *entry;
+
+	st = (TSVectorStat *) funcctx->user_fctx;
+
+	entry = walkStatEntryTree(st);
+
+	if (entry != NULL)
+	{
+		Datum		result;
+		char	   *values[3];
+		char		ndoc[16];
+		char		nentry[16];
+		HeapTuple	tuple;
+
+		values[0] = palloc(entry->lenlexeme + 1);
+		memcpy(values[0], entry->lexeme, entry->lenlexeme);
+		(values[0])[entry->lenlexeme] = '\0';
+		sprintf(ndoc, "%d", entry->ndoc);
+		values[1] = ndoc;
+		sprintf(nentry, "%d", entry->nentry);
+		values[2] = nentry;
+
+		tuple = BuildTupleFromCStrings(funcctx->attinmeta, values);
+		result = HeapTupleGetDatum(tuple);
+
+		pfree(values[0]);
+
+		/* mark entry as already visited */
+		entry->ndoc = 0;
+
+		return result;
+	}
+
+	return (Datum) 0;
+}
+
+static TSVectorStat *
+ts_stat_sql(MemoryContext persistentContext, text *txt, text *ws)
+{
+	char	   *query = text_to_cstring(txt);
+	TSVectorStat *stat;
+	bool		isnull;
+	Portal		portal;
+	SPIPlanPtr	plan;
+
+	if ((plan = SPI_prepare(query, 0, NULL)) == NULL)
+		/* internal error */
+		elog(ERROR, "SPI_prepare(\"%s\") failed", query);
+
+	if ((portal = SPI_cursor_open(NULL, plan, NULL, NULL, true)) == NULL)
+		/* internal error */
+		elog(ERROR, "SPI_cursor_open(\"%s\") failed", query);
+
+	SPI_cursor_fetch(portal, true, 100);
+
+	if (SPI_tuptable == NULL ||
+		SPI_tuptable->tupdesc->natts != 1 ||
+		!IsBinaryCoercible(SPI_gettypeid(SPI_tuptable->tupdesc, 1),
+						   TSVECTOROID))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("ts_stat query must return one tsvector column")));
+
+	stat = MemoryContextAllocZero(persistentContext, sizeof(TSVectorStat));
+	stat->maxdepth = 1;
+
+	if (ws)
+	{
+		char	   *buf;
+
+		buf = VARDATA_ANY(ws);
+		while (buf - VARDATA_ANY(ws) < VARSIZE_ANY_EXHDR(ws))
+		{
+			if (pg_mblen(buf) == 1)
+			{
+				switch (*buf)
+				{
+					case 'A':
+					case 'a':
+						stat->weight |= 1 << 3;
+						break;
+					case 'B':
+					case 'b':
+						stat->weight |= 1 << 2;
+						break;
+					case 'C':
+					case 'c':
+						stat->weight |= 1 << 1;
+						break;
+					case 'D':
+					case 'd':
+						stat->weight |= 1;
+						break;
+					default:
+						stat->weight |= 0;
+				}
+			}
+			buf += pg_mblen(buf);
+		}
+	}
+
+	while (SPI_processed > 0)
+	{
+		uint64		i;
+
+		for (i = 0; i < SPI_processed; i++)
+		{
+			Datum		data = SPI_getbinval(SPI_tuptable->vals[i], SPI_tuptable->tupdesc, 1, &isnull);
+
+			if (!isnull)
+				stat = ts_accum(persistentContext, stat, data);
+		}
+
+		SPI_freetuptable(SPI_tuptable);
+		SPI_cursor_fetch(portal, true, 100);
+	}
+
+	SPI_freetuptable(SPI_tuptable);
+	SPI_cursor_close(portal);
+	SPI_freeplan(plan);
+	pfree(query);
+
+	return stat;
+}
+
+Datum
+ts_stat1(PG_FUNCTION_ARGS)
+{
+	FuncCallContext *funcctx;
+	Datum		result;
+
+	if (SRF_IS_FIRSTCALL())
+	{
+		TSVectorStat *stat;
+		text	   *txt = PG_GETARG_TEXT_PP(0);
+
+		funcctx = SRF_FIRSTCALL_INIT();
+		SPI_connect();
+		stat = ts_stat_sql(funcctx->multi_call_memory_ctx, txt, NULL);
+		PG_FREE_IF_COPY(txt, 0);
+		ts_setup_firstcall(fcinfo, funcctx, stat);
+		SPI_finish();
+	}
+
+	funcctx = SRF_PERCALL_SETUP();
+	if ((result = ts_process_call(funcctx)) != (Datum) 0)
+		SRF_RETURN_NEXT(funcctx, result);
+	SRF_RETURN_DONE(funcctx);
+}
+
+Datum
+ts_stat2(PG_FUNCTION_ARGS)
+{
+	FuncCallContext *funcctx;
+	Datum		result;
+
+	if (SRF_IS_FIRSTCALL())
+	{
+		TSVectorStat *stat;
+		text	   *txt = PG_GETARG_TEXT_PP(0);
+		text	   *ws = PG_GETARG_TEXT_PP(1);
+
+		funcctx = SRF_FIRSTCALL_INIT();
+		SPI_connect();
+		stat = ts_stat_sql(funcctx->multi_call_memory_ctx, txt, ws);
+		PG_FREE_IF_COPY(txt, 0);
+		PG_FREE_IF_COPY(ws, 1);
+		ts_setup_firstcall(fcinfo, funcctx, stat);
+		SPI_finish();
+	}
+
+	funcctx = SRF_PERCALL_SETUP();
+	if ((result = ts_process_call(funcctx)) != (Datum) 0)
+		SRF_RETURN_NEXT(funcctx, result);
+	SRF_RETURN_DONE(funcctx);
+}
+
+
+/*
+ * Triggers for automatic update of a tsvector column from text column(s)
+ *
+ * Trigger arguments are either
+ *		name of tsvector col, name of tsconfig to use, name(s) of text col(s)
+ *		name of tsvector col, name of regconfig col, name(s) of text col(s)
+ * ie, tsconfig can either be specified by name, or indirectly as the
+ * contents of a regconfig field in the row.  If the name is used, it must
+ * be explicitly schema-qualified.
+ */
+Datum
+tsvector_update_trigger_byid(PG_FUNCTION_ARGS)
+{
+	return tsvector_update_trigger(fcinfo, false);
+}
+
+Datum
+tsvector_update_trigger_bycolumn(PG_FUNCTION_ARGS)
+{
+	return tsvector_update_trigger(fcinfo, true);
+}
+
+static Datum
+tsvector_update_trigger(PG_FUNCTION_ARGS, bool config_column)
+{
+	TriggerData *trigdata;
+	Trigger    *trigger;
+	Relation	rel;
+	HeapTuple	rettuple = NULL;
+	int			tsvector_attr_num,
+				i;
+	ParsedText	prs;
+	Datum		datum;
+	bool		isnull;
+	text	   *txt;
+	Oid			cfgId;
+	bool		update_needed;
+
+	/* Check call context */
+	if (!CALLED_AS_TRIGGER(fcinfo)) /* internal error */
+		elog(ERROR, "tsvector_update_trigger: not fired by trigger manager");
+
+	trigdata = (TriggerData *) fcinfo->context;
+	if (!TRIGGER_FIRED_FOR_ROW(trigdata->tg_event))
+		elog(ERROR, "tsvector_update_trigger: must be fired for row");
+	if (!TRIGGER_FIRED_BEFORE(trigdata->tg_event))
+		elog(ERROR, "tsvector_update_trigger: must be fired BEFORE event");
+
+	if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event))
+	{
+		rettuple = trigdata->tg_trigtuple;
+		update_needed = true;
+	}
+	else if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
+	{
+		rettuple = trigdata->tg_newtuple;
+		update_needed = false;	/* computed below */
+	}
+	else
+		elog(ERROR, "tsvector_update_trigger: must be fired for INSERT or UPDATE");
+
+	trigger = trigdata->tg_trigger;
+	rel = trigdata->tg_relation;
+
+	if (trigger->tgnargs < 3)
+		elog(ERROR, "tsvector_update_trigger: arguments must be tsvector_field, ts_config, text_field1, ...)");
+
+	/* Find the target tsvector column */
+	tsvector_attr_num = SPI_fnumber(rel->rd_att, trigger->tgargs[0]);
+	if (tsvector_attr_num == SPI_ERROR_NOATTRIBUTE)
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_COLUMN),
+				 errmsg("tsvector column \"%s\" does not exist",
+						trigger->tgargs[0])));
+	/* This will effectively reject system columns, so no separate test: */
+	if (!IsBinaryCoercible(SPI_gettypeid(rel->rd_att, tsvector_attr_num),
+						   TSVECTOROID))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("column \"%s\" is not of tsvector type",
+						trigger->tgargs[0])));
+
+	/* Find the configuration to use */
+	if (config_column)
+	{
+		int			config_attr_num;
+
+		config_attr_num = SPI_fnumber(rel->rd_att, trigger->tgargs[1]);
+		if (config_attr_num == SPI_ERROR_NOATTRIBUTE)
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_COLUMN),
+					 errmsg("configuration column \"%s\" does not exist",
+							trigger->tgargs[1])));
+		if (!IsBinaryCoercible(SPI_gettypeid(rel->rd_att, config_attr_num),
+							   REGCONFIGOID))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("column \"%s\" is not of regconfig type",
+							trigger->tgargs[1])));
+
+		datum = SPI_getbinval(rettuple, rel->rd_att, config_attr_num, &isnull);
+		if (isnull)
+			ereport(ERROR,
+					(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+					 errmsg("configuration column \"%s\" must not be null",
+							trigger->tgargs[1])));
+		cfgId = DatumGetObjectId(datum);
+	}
+	else
+	{
+		List	   *names;
+
+		names = stringToQualifiedNameList(trigger->tgargs[1], NULL);
+		/* require a schema so that results are not search path dependent */
+		if (list_length(names) < 2)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("text search configuration name \"%s\" must be schema-qualified",
+							trigger->tgargs[1])));
+		cfgId = get_ts_config_oid(names, false);
+	}
+
+	/* initialize parse state */
+	prs.lenwords = 32;
+	prs.curwords = 0;
+	prs.pos = 0;
+	prs.words = (ParsedWord *) palloc(sizeof(ParsedWord) * prs.lenwords);
+
+	/* find all words in indexable column(s) */
+	for (i = 2; i < trigger->tgnargs; i++)
+	{
+		int			numattr;
+
+		numattr = SPI_fnumber(rel->rd_att, trigger->tgargs[i]);
+		if (numattr == SPI_ERROR_NOATTRIBUTE)
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_COLUMN),
+					 errmsg("column \"%s\" does not exist",
+							trigger->tgargs[i])));
+		if (!IsBinaryCoercible(SPI_gettypeid(rel->rd_att, numattr), TEXTOID))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("column \"%s\" is not of a character type",
+							trigger->tgargs[i])));
+
+		if (bms_is_member(numattr - FirstLowInvalidHeapAttributeNumber, trigdata->tg_updatedcols))
+			update_needed = true;
+
+		datum = SPI_getbinval(rettuple, rel->rd_att, numattr, &isnull);
+		if (isnull)
+			continue;
+
+		txt = DatumGetTextPP(datum);
+
+		parsetext(cfgId, &prs, VARDATA_ANY(txt), VARSIZE_ANY_EXHDR(txt));
+
+		if (txt != (text *) DatumGetPointer(datum))
+			pfree(txt);
+	}
+
+	if (update_needed)
+	{
+		/* make tsvector value */
+		datum = TSVectorGetDatum(make_tsvector(&prs));
+		isnull = false;
+
+		/* and insert it into tuple */
+		rettuple = heap_modify_tuple_by_cols(rettuple, rel->rd_att,
+											 1, &tsvector_attr_num,
+											 &datum, &isnull);
+
+		pfree(DatumGetPointer(datum));
+	}
+
+	return PointerGetDatum(rettuple);
+}