Implement operator class parameters

PostgreSQL provides set of template index access methods, where opclasses have
much freedom in the semantics of indexing.  These index AMs are GiST, GIN,
SP-GiST and BRIN.  There opclasses define representation of keys, operations on
them and supported search strategies.  So, it's natural that opclasses may be
faced some tradeoffs, which require user-side decision.  This commit implements
opclass parameters allowing users to set some values, which tell opclass how to
index the particular dataset.

This commit doesn't introduce new storage in system catalog.  Instead it uses
pg_attribute.attoptions, which is used for table column storage options but
unused for index attributes.

In order to evade changing signature of each opclass support function, we
implement unified way to pass options to opclass support functions.  Options
are set to fn_expr as the constant bytea expression.  It's possible due to the
fact that opclass support functions are executed outside of expressions, so
fn_expr is unused for them.

This commit comes with some examples of opclass options usage.  We parametrize
signature length in GiST.  That applies to multiple opclasses: tsvector_ops,
gist__intbig_ops, gist_ltree_ops, gist__ltree_ops, gist_trgm_ops and
gist_hstore_ops.  Also we parametrize maximum number of integer ranges for
gist__int_ops.  However, the main future usage of this feature is expected
to be json, where users would be able to specify which way to index particular
json parts.

Catversion is bumped.

Discussion: https://postgr.es/m/d22c3a18-31c7-1879-fc11-4c1ce2f5e5af%40postgrespro.ru
Author: Nikita Glukhov, revised by me
Reviwed-by: Nikolay Shaplov, Robert Haas, Tom Lane, Tomas Vondra, Alvaro Herrera

1 files changed, 153 insertions, 121 deletions

diff --git a/src/backend/utils/adt/tsgistidx.c b/src/backend/utils/adt/tsgistidx.c
index 8320dcda800..2e0bc3ebd07 100644
--- a/src/backend/utils/adt/tsgistidx.c
+++ b/src/backend/utils/adt/tsgistidx.c
@@ -16,6 +16,7 @@
 
 #include "access/gist.h"
 #include "access/heaptoast.h"
+#include "access/reloptions.h"
 #include "lib/qunique.h"
 #include "port/pg_bitutils.h"
 #include "tsearch/ts_utils.h"
@@ -23,17 +24,25 @@
 #include "utils/pg_crc.h"
 
 
-#define SIGLENINT  31			/* >121 => key will toast, so it will not work
-								 * !!! */
+/* tsvector_ops opclass options */
+typedef struct
+{
+	int32		vl_len_;		/* varlena header (do not touch directly!) */
+	int			siglen;			/* signature length */
+} GistTsVectorOptions;
 
-#define SIGLEN	( sizeof(int32) * SIGLENINT )
-#define SIGLENBIT (SIGLEN * BITS_PER_BYTE)
+#define SIGLEN_DEFAULT	(31 * 4)
+#define SIGLEN_MAX		GISTMaxIndexKeySize
+#define GET_SIGLEN()	(PG_HAS_OPCLASS_OPTIONS() ? \
+						 ((GistTsVectorOptions *) PG_GET_OPCLASS_OPTIONS())->siglen : \
+						 SIGLEN_DEFAULT)
+
+#define SIGLENBIT(siglen) ((siglen) * BITS_PER_BYTE)
 
-typedef char BITVEC[SIGLEN];
 typedef char *BITVECP;
 
-#define LOOPBYTE \
-			for(i=0;i<SIGLEN;i++)
+#define LOOPBYTE(siglen) \
+			for (i = 0; i < siglen; i++)
 
 #define GETBYTE(x,i) ( *( (BITVECP)(x) + (int)( (i) / BITS_PER_BYTE ) ) )
 #define GETBITBYTE(x,i) ( ((char)(x)) >> (i) & 0x01 )
@@ -41,8 +50,8 @@ typedef char *BITVECP;
 #define SETBIT(x,i)   GETBYTE(x,i) |=  ( 0x01 << ( (i) % BITS_PER_BYTE ) )
 #define GETBIT(x,i) ( (GETBYTE(x,i) >> ( (i) % BITS_PER_BYTE )) & 0x01 )
 
-#define HASHVAL(val) (((unsigned int)(val)) % SIGLENBIT)
-#define HASH(sign, val) SETBIT((sign), HASHVAL(val))
+#define HASHVAL(val, siglen) (((unsigned int)(val)) % SIGLENBIT(siglen))
+#define HASH(sign, val, siglen) SETBIT((sign), HASHVAL(val, siglen))
 
 #define GETENTRY(vec,pos) ((SignTSVector *) DatumGetPointer((vec)->vector[(pos)].key))
 
@@ -66,13 +75,14 @@ typedef struct
 #define ISALLTRUE(x)	( ((SignTSVector*)(x))->flag & ALLISTRUE )
 
 #define GTHDRSIZE	( VARHDRSZ + sizeof(int32) )
-#define CALCGTSIZE(flag, len) ( GTHDRSIZE + ( ( (flag) & ARRKEY ) ? ((len)*sizeof(int32)) : (((flag) & ALLISTRUE) ? 0 : SIGLEN) ) )
+#define CALCGTSIZE(flag, len) ( GTHDRSIZE + ( ( (flag) & ARRKEY ) ? ((len)*sizeof(int32)) : (((flag) & ALLISTRUE) ? 0 : (len)) ) )
 
 #define GETSIGN(x)	( (BITVECP)( (char*)(x)+GTHDRSIZE ) )
+#define GETSIGLEN(x)( VARSIZE(x) - GTHDRSIZE )
 #define GETARR(x)	( (int32*)( (char*)(x)+GTHDRSIZE ) )
 #define ARRNELEM(x) ( ( VARSIZE(x) - GTHDRSIZE )/sizeof(int32) )
 
-static int32 sizebitvec(BITVECP sign);
+static int32 sizebitvec(BITVECP sign, int siglen);
 
 Datum
 gtsvectorin(PG_FUNCTION_ARGS)
@@ -103,9 +113,10 @@ gtsvectorout(PG_FUNCTION_ARGS)
 		sprintf(outbuf, ARROUTSTR, (int) ARRNELEM(key));
 	else
 	{
-		int			cnttrue = (ISALLTRUE(key)) ? SIGLENBIT : sizebitvec(GETSIGN(key));
+		int			siglen = GETSIGLEN(key);
+		int			cnttrue = (ISALLTRUE(key)) ? SIGLENBIT(siglen) : sizebitvec(GETSIGN(key), siglen);
 
-		sprintf(outbuf, SINGOUTSTR, cnttrue, (int) SIGLENBIT - cnttrue);
+		sprintf(outbuf, SINGOUTSTR, cnttrue, (int) SIGLENBIT(siglen) - cnttrue);
 	}
 
 	PG_FREE_IF_COPY(key, 0);
@@ -124,36 +135,49 @@ compareint(const void *va, const void *vb)
 }
 
 static void
-makesign(BITVECP sign, SignTSVector *a)
+makesign(BITVECP sign, SignTSVector *a, int siglen)
 {
 	int32		k,
 				len = ARRNELEM(a);
 	int32	   *ptr = GETARR(a);
 
-	MemSet((void *) sign, 0, sizeof(BITVEC));
+	MemSet((void *) sign, 0, siglen);
 	for (k = 0; k < len; k++)
-		HASH(sign, ptr[k]);
+		HASH(sign, ptr[k], siglen);
 }
 
+static SignTSVector *
+gtsvector_alloc(int flag, int len, BITVECP sign)
+{
+	int			size = CALCGTSIZE(flag, len);
+	SignTSVector *res = palloc(size);
+
+	SET_VARSIZE(res, size);
+	res->flag = flag;
+
+	if ((flag & (SIGNKEY | ALLISTRUE)) == SIGNKEY && sign)
+		memcpy(GETSIGN(res), sign, len);
+
+	return res;
+}
+
+
 Datum
 gtsvector_compress(PG_FUNCTION_ARGS)
 {
 	GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
+	int			siglen = GET_SIGLEN();
 	GISTENTRY  *retval = entry;
 
 	if (entry->leafkey)
 	{							/* tsvector */
-		SignTSVector *res;
 		TSVector	val = DatumGetTSVector(entry->key);
+		SignTSVector *res = gtsvector_alloc(ARRKEY, val->size, NULL);
 		int32		len;
 		int32	   *arr;
 		WordEntry  *ptr = ARRPTR(val);
 		char	   *words = STRPTR(val);
 
-		len = CALCGTSIZE(ARRKEY, val->size);
-		res = (SignTSVector *) palloc(len);
-		SET_VARSIZE(res, len);
-		res->flag = ARRKEY;
 		arr = GETARR(res);
 		len = val->size;
 		while (len--)
@@ -185,13 +209,9 @@ gtsvector_compress(PG_FUNCTION_ARGS)
 		/* make signature, if array is too long */
 		if (VARSIZE(res) > TOAST_INDEX_TARGET)
 		{
-			SignTSVector *ressign;
+			SignTSVector *ressign = gtsvector_alloc(SIGNKEY, siglen, NULL);
 
-			len = CALCGTSIZE(SIGNKEY, 0);
-			ressign = (SignTSVector *) palloc(len);
-			SET_VARSIZE(ressign, len);
-			ressign->flag = SIGNKEY;
-			makesign(GETSIGN(ressign), res);
+			makesign(GETSIGN(ressign), res, siglen);
 			res = ressign;
 		}
 
@@ -203,22 +223,17 @@ gtsvector_compress(PG_FUNCTION_ARGS)
 	else if (ISSIGNKEY(DatumGetPointer(entry->key)) &&
 			 !ISALLTRUE(DatumGetPointer(entry->key)))
 	{
-		int32		i,
-					len;
+		int32		i;
 		SignTSVector *res;
 		BITVECP		sign = GETSIGN(DatumGetPointer(entry->key));
 
-		LOOPBYTE
+		LOOPBYTE(siglen)
 		{
 			if ((sign[i] & 0xff) != 0xff)
 				PG_RETURN_POINTER(retval);
 		}
 
-		len = CALCGTSIZE(SIGNKEY | ALLISTRUE, 0);
-		res = (SignTSVector *) palloc(len);
-		SET_VARSIZE(res, len);
-		res->flag = SIGNKEY | ALLISTRUE;
-
+		res = gtsvector_alloc(SIGNKEY | ALLISTRUE, siglen, sign);
 		retval = (GISTENTRY *) palloc(sizeof(GISTENTRY));
 		gistentryinit(*retval, PointerGetDatum(res),
 					  entry->rel, entry->page,
@@ -292,12 +307,14 @@ checkcondition_arr(void *checkval, QueryOperand *val, ExecPhraseData *data)
 static bool
 checkcondition_bit(void *checkval, QueryOperand *val, ExecPhraseData *data)
 {
+	void *key = (SignTSVector *) checkval;
+
 	/*
 	 * we are not able to find a prefix in signature tree
 	 */
 	if (val->prefix)
 		return true;
-	return GETBIT(checkval, HASHVAL(val->valcrc));
+	return GETBIT(GETSIGN(key), HASHVAL(val->valcrc, GETSIGLEN(key)));
 }
 
 Datum
@@ -324,7 +341,7 @@ gtsvector_consistent(PG_FUNCTION_ARGS)
 
 		/* since signature is lossy, cannot specify CALC_NOT here */
 		PG_RETURN_BOOL(TS_execute(GETQUERY(query),
-								  (void *) GETSIGN(key),
+								  key,
 								  TS_EXEC_PHRASE_NO_POS,
 								  checkcondition_bit));
 	}
@@ -342,7 +359,7 @@ gtsvector_consistent(PG_FUNCTION_ARGS)
 }
 
 static int32
-unionkey(BITVECP sbase, SignTSVector *add)
+unionkey(BITVECP sbase, SignTSVector *add, int siglen)
 {
 	int32		i;
 
@@ -353,7 +370,9 @@ unionkey(BITVECP sbase, SignTSVector *add)
 		if (ISALLTRUE(add))
 			return 1;
 
-		LOOPBYTE
+		Assert(GETSIGLEN(add) == siglen);
+
+		LOOPBYTE(siglen)
 			sbase[i] |= sadd[i];
 	}
 	else
@@ -361,7 +380,7 @@ unionkey(BITVECP sbase, SignTSVector *add)
 		int32	   *ptr = GETARR(add);
 
 		for (i = 0; i < ARRNELEM(add); i++)
-			HASH(sbase, ptr[i]);
+			HASH(sbase, ptr[i], siglen);
 	}
 	return 0;
 }
@@ -372,30 +391,24 @@ gtsvector_union(PG_FUNCTION_ARGS)
 {
 	GistEntryVector *entryvec = (GistEntryVector *) PG_GETARG_POINTER(0);
 	int		   *size = (int *) PG_GETARG_POINTER(1);
-	BITVEC		base;
-	int32		i,
-				len;
-	int32		flag = 0;
-	SignTSVector *result;
+	int			siglen = GET_SIGLEN();
+	SignTSVector *result = gtsvector_alloc(SIGNKEY, siglen, NULL);
+	BITVECP		base = GETSIGN(result);
+	int32		i;
+
+	memset(base, 0, siglen);
 
-	MemSet((void *) base, 0, sizeof(BITVEC));
 	for (i = 0; i < entryvec->n; i++)
 	{
-		if (unionkey(base, GETENTRY(entryvec, i)))
+		if (unionkey(base, GETENTRY(entryvec, i), siglen))
 		{
-			flag = ALLISTRUE;
+			result->flag |= ALLISTRUE;
+			SET_VARSIZE(result, CALCGTSIZE(result->flag, siglen));
 			break;
 		}
 	}
 
-	flag |= SIGNKEY;
-	len = CALCGTSIZE(flag, 0);
-	result = (SignTSVector *) palloc(len);
-	*size = len;
-	SET_VARSIZE(result, len);
-	result->flag = flag;
-	if (!ISALLTRUE(result))
-		memcpy((void *) GETSIGN(result), (void *) base, sizeof(BITVEC));
+	*size = VARSIZE(result);
 
 	PG_RETURN_POINTER(result);
 }
@@ -406,6 +419,7 @@ gtsvector_same(PG_FUNCTION_ARGS)
 	SignTSVector *a = (SignTSVector *) PG_GETARG_POINTER(0);
 	SignTSVector *b = (SignTSVector *) PG_GETARG_POINTER(1);
 	bool	   *result = (bool *) PG_GETARG_POINTER(2);
+	int			siglen = GET_SIGLEN();
 
 	if (ISSIGNKEY(a))
 	{							/* then b also ISSIGNKEY */
@@ -421,8 +435,10 @@ gtsvector_same(PG_FUNCTION_ARGS)
 			BITVECP		sa = GETSIGN(a),
 						sb = GETSIGN(b);
 
+			Assert(GETSIGLEN(a) == siglen && GETSIGLEN(b) == siglen);
+
 			*result = true;
-			LOOPBYTE
+			LOOPBYTE(siglen)
 			{
 				if (sa[i] != sb[i])
 				{
@@ -459,19 +475,19 @@ gtsvector_same(PG_FUNCTION_ARGS)
 }
 
 static int32
-sizebitvec(BITVECP sign)
+sizebitvec(BITVECP sign, int siglen)
 {
-	return pg_popcount(sign, SIGLEN);
+	return pg_popcount(sign, siglen);
 }
 
 static int
-hemdistsign(BITVECP a, BITVECP b)
+hemdistsign(BITVECP a, BITVECP b, int siglen)
 {
 	int			i,
 				diff,
 				dist = 0;
 
-	LOOPBYTE
+	LOOPBYTE(siglen)
 	{
 		diff = (unsigned char) (a[i] ^ b[i]);
 		/* Using the popcount functions here isn't likely to win */
@@ -483,17 +499,22 @@ hemdistsign(BITVECP a, BITVECP b)
 static int
 hemdist(SignTSVector *a, SignTSVector *b)
 {
+	int siglena = GETSIGLEN(a);
+	int siglenb = GETSIGLEN(b);
+
 	if (ISALLTRUE(a))
 	{
 		if (ISALLTRUE(b))
 			return 0;
 		else
-			return SIGLENBIT - sizebitvec(GETSIGN(b));
+			return SIGLENBIT(siglenb) - sizebitvec(GETSIGN(b), siglenb);
 	}
 	else if (ISALLTRUE(b))
-		return SIGLENBIT - sizebitvec(GETSIGN(a));
+		return SIGLENBIT(siglena) - sizebitvec(GETSIGN(a), siglena);
+
+	Assert(siglena == siglenb);
 
-	return hemdistsign(GETSIGN(a), GETSIGN(b));
+	return hemdistsign(GETSIGN(a), GETSIGN(b), siglena);
 }
 
 Datum
@@ -502,6 +523,7 @@ gtsvector_penalty(PG_FUNCTION_ARGS)
 	GISTENTRY  *origentry = (GISTENTRY *) PG_GETARG_POINTER(0); /* always ISSIGNKEY */
 	GISTENTRY  *newentry = (GISTENTRY *) PG_GETARG_POINTER(1);
 	float	   *penalty = (float *) PG_GETARG_POINTER(2);
+	int			siglen = GET_SIGLEN();
 	SignTSVector *origval = (SignTSVector *) DatumGetPointer(origentry->key);
 	SignTSVector *newval = (SignTSVector *) DatumGetPointer(newentry->key);
 	BITVECP		orig = GETSIGN(origval);
@@ -510,14 +532,22 @@ gtsvector_penalty(PG_FUNCTION_ARGS)
 
 	if (ISARRKEY(newval))
 	{
-		BITVEC		sign;
+		BITVECP		sign = palloc(siglen);
 
-		makesign(sign, newval);
+		makesign(sign, newval, siglen);
 
 		if (ISALLTRUE(origval))
-			*penalty = ((float) (SIGLENBIT - sizebitvec(sign))) / (float) (SIGLENBIT + 1);
+		{
+			int			siglenbit = SIGLENBIT(siglen);
+
+			*penalty =
+				(float) (siglenbit - sizebitvec(sign, siglen)) /
+				(float) (siglenbit + 1);
+		}
 		else
-			*penalty = hemdistsign(sign, orig);
+			*penalty = hemdistsign(sign, orig, siglen);
+
+		pfree(sign);
 	}
 	else
 		*penalty = hemdist(origval, newval);
@@ -527,19 +557,19 @@ gtsvector_penalty(PG_FUNCTION_ARGS)
 typedef struct
 {
 	bool		allistrue;
-	BITVEC		sign;
+	BITVECP		sign;
 } CACHESIGN;
 
 static void
-fillcache(CACHESIGN *item, SignTSVector *key)
+fillcache(CACHESIGN *item, SignTSVector *key, int siglen)
 {
 	item->allistrue = false;
 	if (ISARRKEY(key))
-		makesign(item->sign, key);
+		makesign(item->sign, key, siglen);
 	else if (ISALLTRUE(key))
 		item->allistrue = true;
 	else
-		memcpy((void *) item->sign, (void *) GETSIGN(key), sizeof(BITVEC));
+		memcpy((void *) item->sign, (void *) GETSIGN(key), siglen);
 }
 
 #define WISH_F(a,b,c) (double)( -(double)(((a)-(b))*((a)-(b))*((a)-(b)))*(c) )
@@ -563,19 +593,19 @@ comparecost(const void *va, const void *vb)
 
 
 static int
-hemdistcache(CACHESIGN *a, CACHESIGN *b)
+hemdistcache(CACHESIGN *a, CACHESIGN *b, int siglen)
 {
 	if (a->allistrue)
 	{
 		if (b->allistrue)
 			return 0;
 		else
-			return SIGLENBIT - sizebitvec(b->sign);
+			return SIGLENBIT(siglen) - sizebitvec(b->sign, siglen);
 	}
 	else if (b->allistrue)
-		return SIGLENBIT - sizebitvec(a->sign);
+		return SIGLENBIT(siglen) - sizebitvec(a->sign, siglen);
 
-	return hemdistsign(a->sign, b->sign);
+	return hemdistsign(a->sign, b->sign, siglen);
 }
 
 Datum
@@ -583,6 +613,7 @@ gtsvector_picksplit(PG_FUNCTION_ARGS)
 {
 	GistEntryVector *entryvec = (GistEntryVector *) PG_GETARG_POINTER(0);
 	GIST_SPLITVEC *v = (GIST_SPLITVEC *) PG_GETARG_POINTER(1);
+	int			siglen = GET_SIGLEN();
 	OffsetNumber k,
 				j;
 	SignTSVector *datum_l,
@@ -602,6 +633,7 @@ gtsvector_picksplit(PG_FUNCTION_ARGS)
 	BITVECP		ptr;
 	int			i;
 	CACHESIGN  *cache;
+	char	   *cache_sign;
 	SPLITCOST  *costvector;
 
 	maxoff = entryvec->n - 2;
@@ -610,16 +642,22 @@ gtsvector_picksplit(PG_FUNCTION_ARGS)
 	v->spl_right = (OffsetNumber *) palloc(nbytes);
 
 	cache = (CACHESIGN *) palloc(sizeof(CACHESIGN) * (maxoff + 2));
-	fillcache(&cache[FirstOffsetNumber], GETENTRY(entryvec, FirstOffsetNumber));
+	cache_sign = palloc(siglen * (maxoff + 2));
+
+	for (j = 0; j < maxoff + 2; j++)
+		cache[j].sign = &cache_sign[siglen * j];
+
+	fillcache(&cache[FirstOffsetNumber], GETENTRY(entryvec, FirstOffsetNumber),
+			  siglen);
 
 	for (k = FirstOffsetNumber; k < maxoff; k = OffsetNumberNext(k))
 	{
 		for (j = OffsetNumberNext(k); j <= maxoff; j = OffsetNumberNext(j))
 		{
 			if (k == FirstOffsetNumber)
-				fillcache(&cache[j], GETENTRY(entryvec, j));
+				fillcache(&cache[j], GETENTRY(entryvec, j), siglen);
 
-			size_waste = hemdistcache(&(cache[j]), &(cache[k]));
+			size_waste = hemdistcache(&(cache[j]), &(cache[k]), siglen);
 			if (size_waste > waste)
 			{
 				waste = size_waste;
@@ -641,44 +679,21 @@ gtsvector_picksplit(PG_FUNCTION_ARGS)
 	}
 
 	/* form initial .. */
-	if (cache[seed_1].allistrue)
-	{
-		datum_l = (SignTSVector *) palloc(CALCGTSIZE(SIGNKEY | ALLISTRUE, 0));
-		SET_VARSIZE(datum_l, CALCGTSIZE(SIGNKEY | ALLISTRUE, 0));
-		datum_l->flag = SIGNKEY | ALLISTRUE;
-	}
-	else
-	{
-		datum_l = (SignTSVector *) palloc(CALCGTSIZE(SIGNKEY, 0));
-		SET_VARSIZE(datum_l, CALCGTSIZE(SIGNKEY, 0));
-		datum_l->flag = SIGNKEY;
-		memcpy((void *) GETSIGN(datum_l), (void *) cache[seed_1].sign, sizeof(BITVEC));
-	}
-	if (cache[seed_2].allistrue)
-	{
-		datum_r = (SignTSVector *) palloc(CALCGTSIZE(SIGNKEY | ALLISTRUE, 0));
-		SET_VARSIZE(datum_r, CALCGTSIZE(SIGNKEY | ALLISTRUE, 0));
-		datum_r->flag = SIGNKEY | ALLISTRUE;
-	}
-	else
-	{
-		datum_r = (SignTSVector *) palloc(CALCGTSIZE(SIGNKEY, 0));
-		SET_VARSIZE(datum_r, CALCGTSIZE(SIGNKEY, 0));
-		datum_r->flag = SIGNKEY;
-		memcpy((void *) GETSIGN(datum_r), (void *) cache[seed_2].sign, sizeof(BITVEC));
-	}
-
+	datum_l = gtsvector_alloc(SIGNKEY | (cache[seed_1].allistrue ? ALLISTRUE : 0),
+							  siglen, cache[seed_1].sign);
+	datum_r = gtsvector_alloc(SIGNKEY | (cache[seed_2].allistrue ? ALLISTRUE : 0),
+							  siglen, cache[seed_2].sign);
 	union_l = GETSIGN(datum_l);
 	union_r = GETSIGN(datum_r);
 	maxoff = OffsetNumberNext(maxoff);
-	fillcache(&cache[maxoff], GETENTRY(entryvec, maxoff));
+	fillcache(&cache[maxoff], GETENTRY(entryvec, maxoff), siglen);
 	/* sort before ... */
 	costvector = (SPLITCOST *) palloc(sizeof(SPLITCOST) * maxoff);
 	for (j = FirstOffsetNumber; j <= maxoff; j = OffsetNumberNext(j))
 	{
 		costvector[j - 1].pos = j;
-		size_alpha = hemdistcache(&(cache[seed_1]), &(cache[j]));
-		size_beta = hemdistcache(&(cache[seed_2]), &(cache[j]));
+		size_alpha = hemdistcache(&(cache[seed_1]), &(cache[j]), siglen);
+		size_beta = hemdistcache(&(cache[seed_2]), &(cache[j]), siglen);
 		costvector[j - 1].cost = Abs(size_alpha - size_beta);
 	}
 	qsort((void *) costvector, maxoff, sizeof(SPLITCOST), comparecost);
@@ -704,36 +719,40 @@ gtsvector_picksplit(PG_FUNCTION_ARGS)
 			if (ISALLTRUE(datum_l) && cache[j].allistrue)
 				size_alpha = 0;
 			else
-				size_alpha = SIGLENBIT - sizebitvec((cache[j].allistrue) ?
-													GETSIGN(datum_l) :
-													GETSIGN(cache[j].sign));
+				size_alpha = SIGLENBIT(siglen) -
+					sizebitvec((cache[j].allistrue) ?
+								GETSIGN(datum_l) :
+								GETSIGN(cache[j].sign),
+								siglen);
 		}
 		else
-			size_alpha = hemdistsign(cache[j].sign, GETSIGN(datum_l));
+			size_alpha = hemdistsign(cache[j].sign, GETSIGN(datum_l), siglen);
 
 		if (ISALLTRUE(datum_r) || cache[j].allistrue)
 		{
 			if (ISALLTRUE(datum_r) && cache[j].allistrue)
 				size_beta = 0;
 			else
-				size_beta = SIGLENBIT - sizebitvec((cache[j].allistrue) ?
-												   GETSIGN(datum_r) :
-												   GETSIGN(cache[j].sign));
+				size_beta = SIGLENBIT(siglen) -
+					sizebitvec((cache[j].allistrue) ?
+							   GETSIGN(datum_r) :
+							   GETSIGN(cache[j].sign),
+							   siglen);
 		}
 		else
-			size_beta = hemdistsign(cache[j].sign, GETSIGN(datum_r));
+			size_beta = hemdistsign(cache[j].sign, GETSIGN(datum_r), siglen);
 
 		if (size_alpha < size_beta + WISH_F(v->spl_nleft, v->spl_nright, 0.1))
 		{
 			if (ISALLTRUE(datum_l) || cache[j].allistrue)
 			{
 				if (!ISALLTRUE(datum_l))
-					MemSet((void *) GETSIGN(datum_l), 0xff, sizeof(BITVEC));
+					MemSet((void *) GETSIGN(datum_l), 0xff, siglen);
 			}
 			else
 			{
 				ptr = cache[j].sign;
-				LOOPBYTE
+				LOOPBYTE(siglen)
 					union_l[i] |= ptr[i];
 			}
 			*left++ = j;
@@ -744,12 +763,12 @@ gtsvector_picksplit(PG_FUNCTION_ARGS)
 			if (ISALLTRUE(datum_r) || cache[j].allistrue)
 			{
 				if (!ISALLTRUE(datum_r))
-					MemSet((void *) GETSIGN(datum_r), 0xff, sizeof(BITVEC));
+					MemSet((void *) GETSIGN(datum_r), 0xff, siglen);
 			}
 			else
 			{
 				ptr = cache[j].sign;
-				LOOPBYTE
+				LOOPBYTE(siglen)
 					union_r[i] |= ptr[i];
 			}
 			*right++ = j;
@@ -776,3 +795,16 @@ gtsvector_consistent_oldsig(PG_FUNCTION_ARGS)
 {
 	return gtsvector_consistent(fcinfo);
 }
+
+Datum
+gtsvector_options(PG_FUNCTION_ARGS)
+{
+	local_relopts *relopts = (local_relopts *) PG_GETARG_POINTER(0);
+
+	init_local_reloptions(relopts, sizeof(GistTsVectorOptions));
+	add_local_int_reloption(relopts, "siglen", "signature length",
+							SIGLEN_DEFAULT, 1, SIGLEN_MAX,
+							offsetof(GistTsVectorOptions, siglen));
+
+	PG_RETURN_VOID();
+}