1 files changed, 62 insertions, 12 deletions

diff --git a/src/backend/access/spgist/spgscan.c b/src/backend/access/spgist/spgscan.c
index 2bd4037af9e..cfba47067cc 100644
--- a/src/backend/access/spgist/spgscan.c
+++ b/src/backend/access/spgist/spgscan.c
@@ -107,13 +107,13 @@ spgAllocSearchItem(SpGistScanOpaque so, bool isnull, double *distances)
 {
 	/* allocate distance array only for non-NULL items */
 	SpGistSearchItem *item =
-	palloc(SizeOfSpGistSearchItem(isnull ? 0 : so->numberOfOrderBys));
+	palloc(SizeOfSpGistSearchItem(isnull ? 0 : so->numberOfNonNullOrderBys));
 
 	item->isNull = isnull;
 
-	if (!isnull && so->numberOfOrderBys > 0)
+	if (!isnull && so->numberOfNonNullOrderBys > 0)
 		memcpy(item->distances, distances,
-			   so->numberOfOrderBys * sizeof(double));
+			   sizeof(item->distances[0]) * so->numberOfNonNullOrderBys);
 
 	return item;
 }
@@ -208,6 +208,34 @@ spgPrepareScanKeys(IndexScanDesc scan)
 	so->numberOfOrderBys = scan->numberOfOrderBys;
 	so->orderByData = scan->orderByData;
 
+	if (so->numberOfOrderBys <= 0)
+		so->numberOfNonNullOrderBys = 0;
+	else
+	{
+		int			j = 0;
+
+		/*
+		 * Remove all NULL keys, but remember their offsets in the original
+		 * array.
+		 */
+		for (i = 0; i < scan->numberOfOrderBys; i++)
+		{
+			ScanKey		skey = &so->orderByData[i];
+
+			if (skey->sk_flags & SK_ISNULL)
+				so->nonNullOrderByOffsets[i] = -1;
+			else
+			{
+				if (i != j)
+					so->orderByData[j] = *skey;
+
+				so->nonNullOrderByOffsets[i] = j++;
+			}
+		}
+
+		so->numberOfNonNullOrderBys = j;
+	}
+
 	if (scan->numberOfKeys <= 0)
 	{
 		/* If no quals, whole-index scan is required */
@@ -295,6 +323,8 @@ spgbeginscan(Relation rel, int keysz, int orderbysz)
 		/* This will be filled in spgrescan, but allocate the space here */
 		so->orderByTypes = (Oid *)
 			palloc(sizeof(Oid) * scan->numberOfOrderBys);
+		so->nonNullOrderByOffsets = (int *)
+			palloc(sizeof(int) * scan->numberOfOrderBys);
 
 		/* These arrays have constant contents, so we can fill them now */
 		so->zeroDistances = (double *)
@@ -394,6 +424,7 @@ spgendscan(IndexScanDesc scan)
 	if (scan->numberOfOrderBys > 0)
 	{
 		pfree(so->orderByTypes);
+		pfree(so->nonNullOrderByOffsets);
 		pfree(so->zeroDistances);
 		pfree(so->infDistances);
 		pfree(scan->xs_orderbyvals);
@@ -465,7 +496,7 @@ spgLeafTest(SpGistScanOpaque so, SpGistSearchItem *item,
 		in.scankeys = so->keyData;
 		in.nkeys = so->numberOfKeys;
 		in.orderbys = so->orderByData;
-		in.norderbys = so->numberOfOrderBys;
+		in.norderbys = so->numberOfNonNullOrderBys;
 		in.reconstructedValue = item->value;
 		in.traversalValue = item->traversalValue;
 		in.level = item->level;
@@ -492,7 +523,7 @@ spgLeafTest(SpGistScanOpaque so, SpGistSearchItem *item,
 	if (result)
 	{
 		/* item passes the scankeys */
-		if (so->numberOfOrderBys > 0)
+		if (so->numberOfNonNullOrderBys > 0)
 		{
 			/* the scan is ordered -> add the item to the queue */
 			MemoryContext oldCxt = MemoryContextSwitchTo(so->traversalCxt);
@@ -531,7 +562,7 @@ spgInitInnerConsistentIn(spgInnerConsistentIn *in,
 	in->scankeys = so->keyData;
 	in->orderbys = so->orderByData;
 	in->nkeys = so->numberOfKeys;
-	in->norderbys = so->numberOfOrderBys;
+	in->norderbys = so->numberOfNonNullOrderBys;
 	in->reconstructedValue = item->value;
 	in->traversalMemoryContext = so->traversalCxt;
 	in->traversalValue = item->traversalValue;
@@ -751,7 +782,7 @@ redirect:
 		if (item->isLeaf)
 		{
 			/* We store heap items in the queue only in case of ordered search */
-			Assert(so->numberOfOrderBys > 0);
+			Assert(so->numberOfNonNullOrderBys > 0);
 			storeRes(so, &item->heapPtr, item->value, item->isNull,
 					 item->recheck, item->recheckDistances, item->distances);
 			reportedSome = true;
@@ -874,7 +905,7 @@ spggetbitmap(IndexScanDesc scan, TIDBitmap *tbm)
 static void
 storeGettuple(SpGistScanOpaque so, ItemPointer heapPtr,
 			  Datum leafValue, bool isnull, bool recheck, bool recheckDistances,
-			  double *distances)
+			  double *nonNullDistances)
 {
 	Assert(so->nPtrs < MaxIndexTuplesPerPage);
 	so->heapPtrs[so->nPtrs] = *heapPtr;
@@ -883,13 +914,33 @@ storeGettuple(SpGistScanOpaque so, ItemPointer heapPtr,
 
 	if (so->numberOfOrderBys > 0)
 	{
-		if (isnull)
+		if (isnull || so->numberOfNonNullOrderBys <= 0)
 			so->distances[so->nPtrs] = NULL;
 		else
 		{
-			Size		size = sizeof(double) * so->numberOfOrderBys;
+			IndexOrderByDistance *distances =
+			palloc(sizeof(distances[0]) * so->numberOfOrderBys);
+			int			i;
+
+			for (i = 0; i < so->numberOfOrderBys; i++)
+			{
+				int			offset = so->nonNullOrderByOffsets[i];
+
+				if (offset >= 0)
+				{
+					/* Copy non-NULL distance value */
+					distances[i].value = nonNullDistances[offset];
+					distances[i].isnull = false;
+				}
+				else
+				{
+					/* Set distance's NULL flag. */
+					distances[i].value = 0.0;
+					distances[i].isnull = true;
+				}
+			}
 
-			so->distances[so->nPtrs] = memcpy(palloc(size), distances, size);
+			so->distances[so->nPtrs] = distances;
 		}
 	}
 
@@ -929,7 +980,6 @@ spggettuple(IndexScanDesc scan, ScanDirection dir)
 			if (so->numberOfOrderBys > 0)
 				index_store_float8_orderby_distances(scan, so->orderByTypes,
 													 so->distances[so->iPtr],
-													 NULL,
 													 so->recheckDistances[so->iPtr]);
 			so->iPtr++;
 			return true;