diff --git a/src/backend/access/hash/hash.c b/src/backend/access/hash/hash.c
index c361509d68..77fd147f68 100644
--- a/src/backend/access/hash/hash.c
+++ b/src/backend/access/hash/hash.c
@@ -231,7 +231,7 @@ hashbuildCallback(Relation index,
 		itup = index_form_tuple(RelationGetDescr(index),
 								index_values, index_isnull);
 		itup->t_tid = *tid;
-		_hash_doinsert(index, itup, buildstate->heapRel);
+		_hash_doinsert(index, itup, buildstate->heapRel, false);
 		pfree(itup);
 	}
 
@@ -265,7 +265,7 @@ hashinsert(Relation rel, Datum *values, bool *isnull,
 	itup = index_form_tuple(RelationGetDescr(rel), index_values, index_isnull);
 	itup->t_tid = *ht_ctid;
 
-	_hash_doinsert(rel, itup, heapRel);
+	_hash_doinsert(rel, itup, heapRel, false);
 
 	pfree(itup);
 
diff --git a/src/backend/access/hash/hashinsert.c b/src/backend/access/hash/hashinsert.c
index 23907d2e5b..6718ff18f3 100644
--- a/src/backend/access/hash/hashinsert.c
+++ b/src/backend/access/hash/hashinsert.c
@@ -32,9 +32,12 @@ static void _hash_vacuum_one_page(Relation rel, Relation hrel,
  *
  *		This routine is called by the public interface routines, hashbuild
  *		and hashinsert.  By here, itup is completely filled in.
+ 
+ * 'sorted' must only be passed as 'true' when inserts are done in hashkey
+ * order.
  */
 void
-_hash_doinsert(Relation rel, IndexTuple itup, Relation heapRel)
+_hash_doinsert(Relation rel, IndexTuple itup, Relation heapRel, bool sorted)
 {
 	Buffer		buf = InvalidBuffer;
 	Buffer		bucket_buf;
@@ -198,7 +201,7 @@ restart_insert:
 	START_CRIT_SECTION();
 
 	/* found page with enough space, so add the item here */
-	itup_off = _hash_pgaddtup(rel, buf, itemsz, itup);
+	itup_off = _hash_pgaddtup(rel, buf, itemsz, itup, sorted);
 	MarkBufferDirty(buf);
 
 	/* metapage operations */
@@ -263,21 +266,42 @@ restart_insert:
  *
  * Returns the offset number at which the tuple was inserted.  This function
  * is responsible for preserving the condition that tuples in a hash index
- * page are sorted by hashkey value.
+ * page are sorted by hashkey value, however, if the caller is certain that
+ * the hashkey for the tuple being added is >= the hashkeys of all existing
+ * tuples on the page, then the 'sorted' flag may be passed as true.
  */
 OffsetNumber
-_hash_pgaddtup(Relation rel, Buffer buf, Size itemsize, IndexTuple itup)
+_hash_pgaddtup(Relation rel, Buffer buf, Size itemsize, IndexTuple itup,
+			   bool sorted)
 {
 	OffsetNumber itup_off;
 	Page		page;
-	uint32		hashkey;
 
 	_hash_checkpage(rel, buf, LH_BUCKET_PAGE | LH_OVERFLOW_PAGE);
 	page = BufferGetPage(buf);
 
-	/* Find where to insert the tuple (preserving page's hashkey ordering) */
-	hashkey = _hash_get_indextuple_hashkey(itup);
-	itup_off = _hash_binsearch(page, hashkey);
+	/*
+	 * Find where to insert the tuple (preserving page's hashkey ordering).
+	 * If the input is already sorted by hashkey, then we can avoid the
+	 * binary search and just add it to the end of the page.
+	 */
+	if (sorted)
+	{
+		itup_off = PageGetMaxOffsetNumber(page) + 1;
+
+		/* check the hashkey for itup is >= to the last existing tuple */
+		Assert(PageGetMaxOffsetNumber(page) == 0 ||
+			   _hash_get_indextuple_hashkey((IndexTuple)
+										PageGetItem(page, PageGetItemId(page,
+											PageGetMaxOffsetNumber(page)))) <=
+						_hash_get_indextuple_hashkey(itup));
+	}
+	else
+	{
+		uint32		hashkey = _hash_get_indextuple_hashkey(itup);
+
+		itup_off = _hash_binsearch(page, hashkey);
+	}
 
 	if (PageAddItem(page, (Item) itup, itemsize, itup_off, false, false)
 		== InvalidOffsetNumber)
diff --git a/src/backend/access/hash/hashsort.c b/src/backend/access/hash/hashsort.c
index 19563148d0..a4ab8384e1 100644
--- a/src/backend/access/hash/hashsort.c
+++ b/src/backend/access/hash/hashsort.c
@@ -145,7 +145,8 @@ _h_indexbuild(HSpool *hspool, Relation heapRel)
 		Assert(hashkey >= lasthashkey);
 #endif
 
-		_hash_doinsert(hspool->index, itup, heapRel);
+		/* the tuples are sorted by hashkey, so pass 'sorted' as true */
+		_hash_doinsert(hspool->index, itup, heapRel, true);
 
 		pgstat_progress_update_param(PROGRESS_CREATEIDX_TUPLES_DONE,
 									 ++tups_done);
diff --git a/src/include/access/hash.h b/src/include/access/hash.h
index da372841c4..3ee37258d2 100644
--- a/src/include/access/hash.h
+++ b/src/include/access/hash.h
@@ -390,9 +390,11 @@ extern void hashadjustmembers(Oid opfamilyoid,
 /* private routines */
 
 /* hashinsert.c */
-extern void _hash_doinsert(Relation rel, IndexTuple itup, Relation heapRel);
+extern void _hash_doinsert(Relation rel, IndexTuple itup, Relation heapRel,
+						   bool sorted);
 extern OffsetNumber _hash_pgaddtup(Relation rel, Buffer buf,
-								   Size itemsize, IndexTuple itup);
+								   Size itemsize, IndexTuple itup,
+								   bool sorted);
 extern void _hash_pgaddmultitup(Relation rel, Buffer buf, IndexTuple *itups,
 								OffsetNumber *itup_offsets, uint16 nitups);