*** a/src/backend/access/nbtree/nbtsearch.c
--- b/src/backend/access/nbtree/nbtsearch.c
***************
*** 997,1002 **** _bt_first(IndexScanDesc scan, ScanDirection dir)
--- 997,1017 ----
  		offnum = OffsetNumberPrev(offnum);
  
  	/*
+ 	 * By here means scan position has been decided based on the first key.
+ 	 * So check if further tuple also expected to match as per direction.
+ 	 * If so then we can set SK_BT_MATCHED flag for this key so that next check
+ 	 * of this key can avoided.
+ 	 */
+ 	if ((startKeys[0]->sk_strategy == BTGreaterEqualStrategyNumber
+ 					|| startKeys[0]->sk_strategy == BTGreaterStrategyNumber)
+ 					&& 	ScanDirectionIsForward(dir))
+ 		startKeys[0]->sk_flags |= SK_BT_MATCHED;
+ 	else if ((startKeys[0]->sk_strategy == BTLessEqualStrategyNumber
+ 					|| startKeys[0]->sk_strategy == BTLessStrategyNumber)
+ 					&& ScanDirectionIsBackward(dir))
+ 		startKeys[0]->sk_flags |= SK_BT_MATCHED;
+ 
+ 	/*
  	 * Now load data from the first page of the scan.
  	 */
  	if (!_bt_readpage(scan, dir, offnum))
*** a/src/backend/access/nbtree/nbtutils.c
--- b/src/backend/access/nbtree/nbtutils.c
***************
*** 1429,1434 **** _bt_checkkeys(IndexScanDesc scan,
--- 1429,1443 ----
  		bool		isNull;
  		Datum		test;
  
+ 		/*
+ 		 * If tuple does not have NULL values and this key has already matched,
+ 		 * then the current tuple is expected to match. So safely deformation of
+ 		 * tuple and comparison of keys can be skiped.
+ 		 */
+ 		if (key->sk_flags & SK_BT_MATCHED && !IndexTupleHasNulls(tuple))
+ 			continue;
+ 
+ 
  		/* row-comparison keys need special processing */
  		if (key->sk_flags & SK_ROW_HEADER)
  		{
*** a/src/include/access/nbtree.h
--- b/src/include/access/nbtree.h
***************
*** 617,622 **** typedef BTScanOpaqueData *BTScanOpaque;
--- 617,623 ----
   */
  #define SK_BT_REQFWD	0x00010000		/* required to continue forward scan */
  #define SK_BT_REQBKWD	0x00020000		/* required to continue backward scan */
+ #define SK_BT_MATCHED	0x00040000		/* required to skip further key match */
  #define SK_BT_INDOPTION_SHIFT  24		/* must clear the above bits */
  #define SK_BT_DESC			(INDOPTION_DESC << SK_BT_INDOPTION_SHIFT)
  #define SK_BT_NULLS_FIRST	(INDOPTION_NULLS_FIRST << SK_BT_INDOPTION_SHIFT)