diff --git a/contrib/pgstattuple/pgstattuple.c b/contrib/pgstattuple/pgstattuple.c
index c3a8b1d..9e06334 100644
--- a/contrib/pgstattuple/pgstattuple.c
+++ b/contrib/pgstattuple/pgstattuple.c
@@ -276,7 +276,7 @@ pgstat_heap(Relation rel, FunctionCallInfo fcinfo)
 	SnapshotData SnapshotDirty;
 
 	/* Disable syncscan because we assume we scan from block zero upwards */
-	scan = heap_beginscan_strat(rel, SnapshotAny, 0, NULL, true, false);
+	scan = heap_beginscan_strat(rel, SnapshotAny, 0, NULL, true, false, false);
 	InitDirtySnapshot(SnapshotDirty);
 
 	nblocks = scan->rs_nblocks; /* # blocks to be scanned */
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index 457cd70..19675da 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -80,7 +80,8 @@ static HeapScanDesc heap_beginscan_internal(Relation relation,
 						Snapshot snapshot,
 						int nkeys, ScanKey key,
 						bool allow_strat, bool allow_sync,
-						bool is_bitmapscan, bool temp_snap);
+						bool is_bitmapscan, bool temp_snap,
+						bool always_prune);
 static HeapTuple heap_prepare_insert(Relation relation, HeapTuple tup,
 					TransactionId xid, CommandId cid, int options);
 static XLogRecPtr log_heap_update(Relation reln, Buffer oldbuf,
@@ -354,9 +355,15 @@ heapgetpage(HeapScanDesc scan, BlockNumber page)
 	snapshot = scan->rs_snapshot;
 
 	/*
-	 * Prune and repair fragmentation for the whole page, if possible.
+	 * Prune and repair fragmentation for the whole page, if possible and
+	 * within limits, if any.
 	 */
-	heap_page_prune_opt(scan->rs_rd, buffer);
+	if (scan->rs_prune_count < PRUNE_LIMIT_PER_SCAN ||
+		scan->rs_always_prune)
+	{
+		if (heap_page_prune_opt(scan->rs_rd, buffer) && !scan->rs_always_prune)
+			scan->rs_prune_count++;
+	}
 
 	/*
 	 * We must hold share lock on the buffer content while examining tuple
@@ -1291,7 +1298,8 @@ heap_openrv_extended(const RangeVar *relation, LOCKMODE lockmode,
  * heap_beginscan_strat offers an extended API that lets the caller control
  * whether a nondefault buffer access strategy can be used, and whether
  * syncscan can be chosen (possibly resulting in the scan not starting from
- * block zero).  Both of these default to TRUE with plain heap_beginscan.
+ * block zero).  Both of these default to TRUE with plain heap_beginscan,
+ * while always_prune defaults to FALSE for regular scans.
  *
  * heap_beginscan_bm is an alternative entry point for setting up a
  * HeapScanDesc for a bitmap heap scan.  Although that scan technology is
@@ -1304,7 +1312,7 @@ heap_beginscan(Relation relation, Snapshot snapshot,
 			   int nkeys, ScanKey key)
 {
 	return heap_beginscan_internal(relation, snapshot, nkeys, key,
-								   true, true, false, false);
+								   true, true, false, false, false);
 }
 
 HeapScanDesc
@@ -1314,31 +1322,33 @@ heap_beginscan_catalog(Relation relation, int nkeys, ScanKey key)
 	Snapshot	snapshot = RegisterSnapshot(GetCatalogSnapshot(relid));
 
 	return heap_beginscan_internal(relation, snapshot, nkeys, key,
-								   true, true, false, true);
+								   true, true, false, true, true);
 }
 
 HeapScanDesc
 heap_beginscan_strat(Relation relation, Snapshot snapshot,
 					 int nkeys, ScanKey key,
-					 bool allow_strat, bool allow_sync)
+					 bool allow_strat, bool allow_sync, bool always_prune)
 {
 	return heap_beginscan_internal(relation, snapshot, nkeys, key,
-								   allow_strat, allow_sync, false, false);
+								   allow_strat, allow_sync, false, false,
+								   always_prune);
 }
 
 HeapScanDesc
 heap_beginscan_bm(Relation relation, Snapshot snapshot,
-				  int nkeys, ScanKey key)
+				  int nkeys, ScanKey key, bool always_prune)
 {
 	return heap_beginscan_internal(relation, snapshot, nkeys, key,
-								   false, false, true, false);
+								   false, false, true, false, always_prune);
 }
 
 static HeapScanDesc
 heap_beginscan_internal(Relation relation, Snapshot snapshot,
 						int nkeys, ScanKey key,
 						bool allow_strat, bool allow_sync,
-						bool is_bitmapscan, bool temp_snap)
+						bool is_bitmapscan, bool temp_snap,
+						bool always_prune)
 {
 	HeapScanDesc scan;
 
@@ -1365,6 +1375,9 @@ heap_beginscan_internal(Relation relation, Snapshot snapshot,
 	scan->rs_allow_sync = allow_sync;
 	scan->rs_temp_snap = temp_snap;
 
+	scan->rs_prune_count = 0;
+	scan->rs_always_prune = always_prune;
+
 	/*
 	 * we can use page-at-a-time mode if it's an MVCC-safe snapshot
 	 */
diff --git a/src/backend/access/heap/pruneheap.c b/src/backend/access/heap/pruneheap.c
index 563e5c3..579070f 100644
--- a/src/backend/access/heap/pruneheap.c
+++ b/src/backend/access/heap/pruneheap.c
@@ -70,8 +70,10 @@ static void heap_prune_record_unused(PruneState *prstate, OffsetNumber offnum);
  *
  * OldestXmin is the cutoff XID used to distinguish whether tuples are DEAD
  * or RECENTLY_DEAD (see HeapTupleSatisfiesVacuum).
+ *
+ * Returns true if the block was cleaned.
  */
-void
+bool
 heap_page_prune_opt(Relation relation, Buffer buffer)
 {
 	Page		page = BufferGetPage(buffer);
@@ -84,7 +86,7 @@ heap_page_prune_opt(Relation relation, Buffer buffer)
 	 * anyway, so this is no particular loss.
 	 */
 	if (RecoveryInProgress())
-		return;
+		return false;
 
 	/*
 	 * Use the appropriate xmin horizon for this relation. If it's a proper
@@ -108,7 +110,7 @@ heap_page_prune_opt(Relation relation, Buffer buffer)
 	 * older than OldestXmin.
 	 */
 	if (!PageIsPrunable(page, OldestXmin))
-		return;
+		return false;
 
 	/*
 	 * We prune when a previous UPDATE failed to find enough space on the page
@@ -130,7 +132,7 @@ heap_page_prune_opt(Relation relation, Buffer buffer)
 	{
 		/* OK, try to get exclusive buffer lock */
 		if (!ConditionalLockBufferForCleanup(buffer))
-			return;
+			return false;
 
 		/*
 		 * Now that we have buffer lock, get accurate information about the
@@ -149,7 +151,11 @@ heap_page_prune_opt(Relation relation, Buffer buffer)
 
 		/* And release buffer lock */
 		LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
+
+		return true;
 	}
+
+	return false;
 }
 
 
diff --git a/src/backend/access/index/genam.c b/src/backend/access/index/genam.c
index e6e4d28..3e826b5 100644
--- a/src/backend/access/index/genam.c
+++ b/src/backend/access/index/genam.c
@@ -390,7 +390,7 @@ systable_beginscan(Relation heapRelation,
 		 */
 		sysscan->scan = heap_beginscan_strat(heapRelation, snapshot,
 											 nkeys, key,
-											 true, false);
+											 true, false, true);
 		sysscan->iscan = NULL;
 	}
 
diff --git a/src/backend/access/index/indexam.c b/src/backend/access/index/indexam.c
index 2b27e73..5a97d94 100644
--- a/src/backend/access/index/indexam.c
+++ b/src/backend/access/index/indexam.c
@@ -249,10 +249,41 @@ index_beginscan(Relation heapRelation,
 
 	/*
 	 * Save additional parameters into the scandesc.  Everything else was set
+	 * up by RelationGetIndexScan. Disable pruning in all cases.
+	 */
+	scan->heapRelation = heapRelation;
+	scan->xs_snapshot = snapshot;
+	scan->xs_always_prune = true;
+	scan->xs_prune_count = 0;
+
+	return scan;
+}
+
+/*
+ * index_beginscan_strat - start a scan of an index with amgettuple
+ * allowing caller to specify additional scan strategies.
+ *
+ * Caller must be holding suitable locks on the heap and the index.
+ */
+IndexScanDesc
+index_beginscan_strat(Relation heapRelation,
+				Relation indexRelation,
+				Snapshot snapshot,
+				int nkeys, int norderbys,
+				bool always_prune)
+{
+	IndexScanDesc scan;
+
+	scan = index_beginscan_internal(indexRelation, nkeys, norderbys, snapshot);
+
+	/*
+	 * Save additional parameters into the scandesc.  Everything else was set
 	 * up by RelationGetIndexScan.
 	 */
 	scan->heapRelation = heapRelation;
 	scan->xs_snapshot = snapshot;
+	scan->xs_always_prune = always_prune;
+	scan->xs_prune_count = 0;
 
 	return scan;
 }
@@ -278,6 +309,10 @@ index_beginscan_bitmap(Relation indexRelation,
 	 */
 	scan->xs_snapshot = snapshot;
 
+	/* BitmapHeapScan does pruning if required */
+	scan->xs_always_prune = false;
+	scan->xs_prune_count = 0;
+
 	return scan;
 }
 
@@ -520,10 +555,15 @@ index_fetch_heap(IndexScanDesc scan)
 											 ItemPointerGetBlockNumber(tid));
 
 		/*
-		 * Prune page, but only if we weren't already on this page
+		 * Prune page if enabled, but only if we weren't already on this page
 		 */
-		if (prev_buf != scan->xs_cbuf)
-			heap_page_prune_opt(scan->heapRelation, scan->xs_cbuf);
+		if (prev_buf != scan->xs_cbuf &&
+			(scan->xs_prune_count < PRUNE_LIMIT_PER_SCAN ||
+			 scan->xs_always_prune))
+		{
+			if (heap_page_prune_opt(scan->heapRelation, scan->xs_cbuf) && !scan->xs_always_prune)
+				scan->xs_prune_count++;
+		}
 	}
 
 	/* Obtain share-lock on the buffer so we can examine visibility */
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index d8ff554..fa74b0a 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -2196,7 +2196,8 @@ IndexBuildHeapRangeScan(Relation heapRelation,
 								0,		/* number of keys */
 								NULL,	/* scan key */
 								true,	/* buffer access strategy OK */
-								allow_sync);	/* syncscan OK? */
+								allow_sync,	/* syncscan OK? */
+								false);		/* pruning optional */
 
 	/* set our scan endpoints */
 	heap_setscanlimits(scan, start_blockno, numblocks);
@@ -2577,7 +2578,8 @@ IndexCheckExclusion(Relation heapRelation,
 								0,		/* number of keys */
 								NULL,	/* scan key */
 								true,	/* buffer access strategy OK */
-								true);	/* syncscan OK */
+								true,	/* syncscan OK */
+								false);		/* pruning optional*/
 
 	while ((heapTuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
 	{
@@ -2851,7 +2853,8 @@ validate_index_heapscan(Relation heapRelation,
 								0,		/* number of keys */
 								NULL,	/* scan key */
 								true,	/* buffer access strategy OK */
-								false); /* syncscan not OK */
+								false, /* syncscan not OK */
+								false);		/* pruning optional */
 
 	/*
 	 * Scan all tuples matching the snapshot.
diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c
index 8ea8b9f..9dd4c50 100644
--- a/src/backend/executor/nodeBitmapHeapscan.c
+++ b/src/backend/executor/nodeBitmapHeapscan.c
@@ -334,9 +334,15 @@ bitgetpage(HeapScanDesc scan, TBMIterateResult *tbmres)
 	ntup = 0;
 
 	/*
-	 * Prune and repair fragmentation for the whole page, if possible.
+	 * Prune and repair fragmentation for the whole page, if possible
+	 * and within limits, if any.
 	 */
-	heap_page_prune_opt(scan->rs_rd, buffer);
+	if (scan->rs_prune_count < PRUNE_LIMIT_PER_SCAN ||
+		scan->rs_always_prune)
+	{
+		if (heap_page_prune_opt(scan->rs_rd, buffer) && !scan->rs_always_prune)
+			scan->rs_prune_count++;
+	}
 
 	/*
 	 * We must hold share lock on the buffer content while examining tuple
@@ -537,6 +543,7 @@ ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags)
 {
 	BitmapHeapScanState *scanstate;
 	Relation	currentRelation;
+	bool		relistarget;
 
 	/* check for unsupported flags */
 	Assert(!(eflags & (EXEC_FLAG_BACKWARD | EXEC_FLAG_MARK)));
@@ -597,6 +604,7 @@ ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags)
 	currentRelation = ExecOpenScanRelation(estate, node->scan.scanrelid, eflags);
 
 	scanstate->ss.ss_currentRelation = currentRelation;
+	relistarget = ExecRelationIsTargetRelation(estate, node->scan.scanrelid);
 
 	/*
 	 * Even though we aren't going to do a conventional seqscan, it is useful
@@ -605,7 +613,8 @@ ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags)
 	scanstate->ss.ss_currentScanDesc = heap_beginscan_bm(currentRelation,
 														 estate->es_snapshot,
 														 0,
-														 NULL);
+														 NULL,
+														 relistarget);
 
 	/*
 	 * get the scan type from the relation descriptor.
diff --git a/src/backend/executor/nodeIndexonlyscan.c b/src/backend/executor/nodeIndexonlyscan.c
index 06b7c3c..d8045dc 100644
--- a/src/backend/executor/nodeIndexonlyscan.c
+++ b/src/backend/executor/nodeIndexonlyscan.c
@@ -523,11 +523,12 @@ ExecInitIndexOnlyScan(IndexOnlyScan *node, EState *estate, int eflags)
 	/*
 	 * Initialize scan descriptor.
 	 */
-	indexstate->ioss_ScanDesc = index_beginscan(currentRelation,
+	indexstate->ioss_ScanDesc = index_beginscan_strat(currentRelation,
 												indexstate->ioss_RelationDesc,
 												estate->es_snapshot,
 												indexstate->ioss_NumScanKeys,
-											indexstate->ioss_NumOrderByKeys);
+											indexstate->ioss_NumOrderByKeys,
+											relistarget);
 
 	/* Set it up for index-only scan */
 	indexstate->ioss_ScanDesc->xs_want_itup = true;
diff --git a/src/backend/executor/nodeIndexscan.c b/src/backend/executor/nodeIndexscan.c
index 48fa919..e2ec902 100644
--- a/src/backend/executor/nodeIndexscan.c
+++ b/src/backend/executor/nodeIndexscan.c
@@ -603,11 +603,12 @@ ExecInitIndexScan(IndexScan *node, EState *estate, int eflags)
 	/*
 	 * Initialize scan descriptor.
 	 */
-	indexstate->iss_ScanDesc = index_beginscan(currentRelation,
+	indexstate->iss_ScanDesc = index_beginscan_strat(currentRelation,
 											   indexstate->iss_RelationDesc,
 											   estate->es_snapshot,
 											   indexstate->iss_NumScanKeys,
-											 indexstate->iss_NumOrderByKeys);
+											   indexstate->iss_NumOrderByKeys,
+											   relistarget);
 
 	/*
 	 * If no run-time keys to calculate, go ahead and pass the scankeys to the
diff --git a/src/backend/executor/nodeSeqscan.c b/src/backend/executor/nodeSeqscan.c
index 3cb81fc..eadf0b3 100644
--- a/src/backend/executor/nodeSeqscan.c
+++ b/src/backend/executor/nodeSeqscan.c
@@ -124,20 +124,30 @@ InitScanRelation(SeqScanState *node, EState *estate, int eflags)
 {
 	Relation	currentRelation;
 	HeapScanDesc currentScanDesc;
+	Oid			currentRelid;
+	bool		relistarget;
+
+	/*
+	 * get the relation object id from the relid'th entry in the range table
+	 */
+	currentRelid = ((SeqScan *) node->ps.plan)->scanrelid,
+	relistarget = ExecRelationIsTargetRelation(estate, currentRelid);
 
 	/*
-	 * get the relation object id from the relid'th entry in the range table,
 	 * open that relation and acquire appropriate lock on it.
 	 */
 	currentRelation = ExecOpenScanRelation(estate,
-									  ((SeqScan *) node->ps.plan)->scanrelid,
+										   currentRelid,
 										   eflags);
 
 	/* initialize a heapscan */
-	currentScanDesc = heap_beginscan(currentRelation,
+	currentScanDesc = heap_beginscan_strat(currentRelation,
 									 estate->es_snapshot,
 									 0,
-									 NULL);
+									 NULL,
+									 true,
+									 true,
+									 relistarget);
 
 	node->ss_currentRelation = currentRelation;
 	node->ss_currentScanDesc = currentScanDesc;
diff --git a/src/include/access/genam.h b/src/include/access/genam.h
index d86590a..738bd35 100644
--- a/src/include/access/genam.h
+++ b/src/include/access/genam.h
@@ -135,6 +135,10 @@ extern IndexScanDesc index_beginscan(Relation heapRelation,
 				Relation indexRelation,
 				Snapshot snapshot,
 				int nkeys, int norderbys);
+extern IndexScanDesc index_beginscan_strat(Relation heapRelation,
+				Relation indexRelation,
+				Snapshot snapshot,
+				int nkeys, int norderbys, bool always_prune);
 extern IndexScanDesc index_beginscan_bitmap(Relation indexRelation,
 					   Snapshot snapshot,
 					   int nkeys);
diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h
index 888cce7..e907eeb 100644
--- a/src/include/access/heapam.h
+++ b/src/include/access/heapam.h
@@ -110,9 +110,9 @@ extern HeapScanDesc heap_beginscan_catalog(Relation relation, int nkeys,
 					   ScanKey key);
 extern HeapScanDesc heap_beginscan_strat(Relation relation, Snapshot snapshot,
 					 int nkeys, ScanKey key,
-					 bool allow_strat, bool allow_sync);
+					 bool allow_strat, bool allow_sync, bool always_prune);
 extern HeapScanDesc heap_beginscan_bm(Relation relation, Snapshot snapshot,
-				  int nkeys, ScanKey key);
+				  int nkeys, ScanKey key, bool always_prune);
 extern void heap_setscanlimits(HeapScanDesc scan, BlockNumber startBlk,
 		   BlockNumber endBlk);
 extern void heap_rescan(HeapScanDesc scan, ScanKey key);
@@ -164,7 +164,7 @@ extern void simple_heap_update(Relation relation, ItemPointer otid,
 extern void heap_sync(Relation relation);
 
 /* in heap/pruneheap.c */
-extern void heap_page_prune_opt(Relation relation, Buffer buffer);
+extern bool heap_page_prune_opt(Relation relation, Buffer buffer);
 extern int heap_page_prune(Relation relation, Buffer buffer,
 				TransactionId OldestXmin,
 				bool report_stats, TransactionId *latestRemovedXid);
diff --git a/src/include/access/relscan.h b/src/include/access/relscan.h
index 9bb6362..a745876 100644
--- a/src/include/access/relscan.h
+++ b/src/include/access/relscan.h
@@ -20,6 +20,7 @@
 #include "access/itup.h"
 #include "access/tupdesc.h"
 
+#define PRUNE_LIMIT_PER_SCAN	4
 
 typedef struct HeapScanDescData
 {
@@ -34,6 +35,9 @@ typedef struct HeapScanDescData
 	bool		rs_allow_sync;	/* allow or disallow use of syncscan */
 	bool		rs_temp_snap;	/* unregister snapshot at scan end? */
 
+	bool		rs_always_prune;/* Unlimited pruning allowed */
+	int			rs_prune_count;	/* Number of blocks pruned during this scan */
+
 	/* state set up at initscan time */
 	BlockNumber rs_nblocks;		/* total number of blocks in rel */
 	BlockNumber rs_startblock;	/* block # to start at */
@@ -72,6 +76,9 @@ typedef struct IndexScanDescData
 	ScanKey		orderByData;	/* array of ordering op descriptors */
 	bool		xs_want_itup;	/* caller requests index tuples */
 
+	bool		xs_always_prune;/* Unlimited pruning allowed */
+	int			xs_prune_count;	/* Number of blocks pruned during this scan */
+
 	/* signaling to index AM about killing index tuples */
 	bool		kill_prior_tuple;		/* last-returned tuple is dead */
 	bool		ignore_killed_tuples;	/* do not return killed entries */