*** src/backend/access/index/genam.c
--- src/backend/access/index/genam.c
***************
*** 194,209 **** systable_beginscan(Relation heapRelation,
  	{
  		int			i;
  
! 		/*
! 		 * Change attribute numbers to be index column numbers.
! 		 *
! 		 * This code could be generalized to search for the index key numbers
! 		 * to substitute, but for now there's no need.
! 		 */
  		for (i = 0; i < nkeys; i++)
  		{
! 			Assert(key[i].sk_attno == irel->rd_index->indkey.values[i]);
! 			key[i].sk_attno = i + 1;
  		}
  
  		sysscan->iscan = index_beginscan(heapRelation, irel,
--- 194,214 ----
  	{
  		int			i;
  
! 		/* Change attribute numbers to be index column numbers. */
  		for (i = 0; i < nkeys; i++)
  		{
! 			int j;
! 
! 			for (j = 0; j < irel->rd_index->indnatts; j++)
! 			{
! 				if (key[i].sk_attno == irel->rd_index->indkey.values[j])
! 				{
! 					key[i].sk_attno = j + 1;
! 					break;
! 				}
! 			}
! 			if (j == irel->rd_index->indnatts)
! 				elog(ERROR, "column is not in index");
  		}
  
  		sysscan->iscan = index_beginscan(heapRelation, irel,
***************
*** 352,367 **** systable_beginscan_ordered(Relation heapRelation,
  	sysscan->heap_rel = heapRelation;
  	sysscan->irel = indexRelation;
  
! 	/*
! 	 * Change attribute numbers to be index column numbers.
! 	 *
! 	 * This code could be generalized to search for the index key numbers
! 	 * to substitute, but for now there's no need.
! 	 */
  	for (i = 0; i < nkeys; i++)
  	{
! 		Assert(key[i].sk_attno == indexRelation->rd_index->indkey.values[i]);
! 		key[i].sk_attno = i + 1;
  	}
  
  	sysscan->iscan = index_beginscan(heapRelation, indexRelation,
--- 357,377 ----
  	sysscan->heap_rel = heapRelation;
  	sysscan->irel = indexRelation;
  
! 	/* Change attribute numbers to be index column numbers. */
  	for (i = 0; i < nkeys; i++)
  	{
! 		int j;
! 
! 		for (j = 0; j < indexRelation->rd_index->indnatts; j++)
! 		{
! 			if (key[i].sk_attno == indexRelation->rd_index->indkey.values[j])
! 			{
! 				key[i].sk_attno = j + 1;
! 				break;
! 			}
! 		}
! 		if (j == indexRelation->rd_index->indnatts)
! 			elog(ERROR, "column is not in index");
  	}
  
  	sysscan->iscan = index_beginscan(heapRelation, indexRelation,