add more frame types in window functions (ROWS)

*** a/doc/src/sgml/ref/select.sgml
--- b/doc/src/sgml/ref/select.sgml
***************
*** 619,631 **** WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
      frame (not all do).  It can be one of
  <synopsis>
  RANGE UNBOUNDED PRECEDING
  RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW
  RANGE BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING
  ROWS UNBOUNDED PRECEDING
  ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW
  ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING
  </synopsis>
!     The first two are equivalent and are also the default: they set the
      frame to be all rows from the partition start up through the current row's
      last peer in the <literal>ORDER BY</> ordering (which means all rows if
      there is no <literal>ORDER BY</>).  The options
--- 619,646 ----
      frame (not all do).  It can be one of
  <synopsis>
  RANGE UNBOUNDED PRECEDING
+ RANGE CURRENT ROW
  RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW
  RANGE BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING
+ RANGE BETWEEN CURRENT ROW AND CURRENT ROW
+ RANGE BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
  ROWS UNBOUNDED PRECEDING
+ ROWS <replaceable>unsigned value</replaceable> PRECEDING
+ ROWS CURRENT ROW
  ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW
+ ROWS BETWEEN UNBOUNDED PRECEDING AND <replaceable>unsigned value</replaceable> FOLLOWING
  ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING
+ ROWS BETWEEN <replaceable>unsigned value</replaceable> PRECEDING AND <replaceable>unsigned value</replaceable> PRECEDING
+ ROWS BETWEEN <replaceable>unsigned value</replaceable> PRECEDING AND CURRENT ROW
+ ROWS BETWEEN <replaceable>unsigned value</replaceable> PRECEDING AND <replaceable>unsigned value</replaceable> FOLLOWING
+ ROWS BETWEEN <replaceable>unsigned value</replaceable> PRECEDING AND UNBOUNDED FOLLOWING
+ ROWS BETWEEN CURRENT ROW AND CURRENT ROW
+ ROWS BETWEEN CURRENT ROW AND <replaceable>unsigned value</replaceable> FOLLOWING
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ ROWS BETWEEN <replaceable>unsigned value</replaceable> FOLLOWING AND <replaceable>unsigned value</replaceable> FOLLOWING
+ ROWS BETWEEN <replaceable>unsigned value</replaceable> AND UNBOUNDED FOLLOWING
  </synopsis>
!     The first and the third are equivalent and are also the default: they set the
      frame to be all rows from the partition start up through the current row's
      last peer in the <literal>ORDER BY</> ordering (which means all rows if
      there is no <literal>ORDER BY</>).  The options
***************
*** 637,642 **** ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING
--- 652,664 ----
      all rows up through the current row (regardless of duplicates).
      Beware that this option can produce implementation-dependent results
      if the <literal>ORDER BY</> ordering does not order the rows uniquely.
+     The <replaceable>unsigned value</replaceable> in <literal>PRECEDING</>
+     or <literal>FOLLOWING</> means how far the frame bound is off from the
+     current row. In <literal>ROWS</> mode this value means phisical row
+     number from the current row and only integer value is allowed. In
+     <literal>RANGE</> mode this value can also be specified in SQL standard
+     altough PostgreSQL doesn't support it currently. You can specify
+     any expression for this value except for column reference.
     </para>
  
     <para>
*** a/doc/src/sgml/syntax.sgml
--- b/doc/src/sgml/syntax.sgml
***************
*** 1638,1648 **** sqrt(2)
--- 1638,1663 ----
      can be one of
  <synopsis>
  RANGE UNBOUNDED PRECEDING
+ RANGE CURRENT ROW
  RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW
  RANGE BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING
+ RANGE BETWEEN CURRENT ROW AND CURRENT ROW
+ RANGE BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
  ROWS UNBOUNDED PRECEDING
+ ROWS <replaceable>unsigned value</replaceable> PRECEDING
+ ROWS CURRENT ROW
  ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW
+ ROWS BETWEEN UNBOUNDED PRECEDING AND <replaceable>unsigned value</replaceable> FOLLOWING
  ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING
+ ROWS BETWEEN <replaceable>unsigned value</replaceable> PRECEDING AND <replaceable>unsigned value</replaceable> PRECEDING
+ ROWS BETWEEN <replaceable>unsigned value</replaceable> PRECEDING AND CURRENT ROW
+ ROWS BETWEEN <replaceable>unsigned value</replaceable> PRECEDING AND <replaceable>unsigned value</replaceable> FOLLOWING
+ ROWS BETWEEN <replaceable>unsigned value</replaceable> PRECEDING AND UNBOUNDED FOLLOWING
+ ROWS BETWEEN CURRENT ROW AND CURRENT ROW
+ ROWS BETWEEN CURRENT ROW AND <replaceable>unsigned value</replaceable> FOLLOWING
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ ROWS BETWEEN <replaceable>unsigned value</replaceable> FOLLOWING AND <replaceable>unsigned value</replaceable> FOLLOWING
+ ROWS BETWEEN <replaceable>unsigned value</replaceable> AND UNBOUNDED FOLLOWING
  </synopsis>
  
      Here, <replaceable>expression</replaceable> represents any value
***************
*** 1682,1687 **** ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING
--- 1697,1713 ----
      all rows up through the current row (regardless of duplicates).
      Beware that this option can produce implementation-dependent results
      if the <literal>ORDER BY</> ordering does not order the rows uniquely.
+   </para>
+ 
+   <para>
+     The <replaceable>unsigned value</replaceable> in <literal>PRECEDING</>
+     or <literal>FOLLOWING</> tells how far the frame bound is off from
+     the current row. In <literal>ROWS</> mode this value means phisical
+     row number off from the current row and thus must be zero or positive
+     integer. The syntax of <literal>RANGE</> mode offset value is defined
+     in SQL standard but is not supported currently. You can specify any
+     expression except for column reference that changes row by row for
+     this value.
     </para>
  
     <para>
*** a/src/backend/executor/nodeWindowAgg.c
--- b/src/backend/executor/nodeWindowAgg.c
***************
*** 164,170 **** static void spool_tuples(WindowAggState *winstate, int64 pos);
  static void release_partition(WindowAggState *winstate);
  
  static bool row_is_in_frame(WindowAggState *winstate, int64 pos,
! 				TupleTableSlot *slot);
  static void update_frametailpos(WindowObject winobj, TupleTableSlot *slot);
  
  static WindowStatePerAggData *initialize_peragg(WindowAggState *winstate,
--- 164,171 ----
  static void release_partition(WindowAggState *winstate);
  
  static bool row_is_in_frame(WindowAggState *winstate, int64 pos,
! 							TupleTableSlot *slot);
! static void update_frameheadpos(WindowObject winobj, TupleTableSlot *slot);
  static void update_frametailpos(WindowObject winobj, TupleTableSlot *slot);
  
  static WindowStatePerAggData *initialize_peragg(WindowAggState *winstate,
***************
*** 193,199 **** initialize_windowaggregate(WindowAggState *winstate,
  		peraggstate->transValue = peraggstate->initValue;
  	else
  	{
! 		oldContext = MemoryContextSwitchTo(winstate->wincontext);
  		peraggstate->transValue = datumCopy(peraggstate->initValue,
  											peraggstate->transtypeByVal,
  											peraggstate->transtypeLen);
--- 194,200 ----
  		peraggstate->transValue = peraggstate->initValue;
  	else
  	{
! 		oldContext = MemoryContextSwitchTo(winstate->aggcontext);
  		peraggstate->transValue = datumCopy(peraggstate->initValue,
  											peraggstate->transtypeByVal,
  											peraggstate->transtypeLen);
***************
*** 258,267 **** advance_windowaggregate(WindowAggState *winstate,
  			 * already checked that the agg's input type is binary-compatible
  			 * with its transtype, so straight copy here is OK.)
  			 *
! 			 * We must copy the datum into wincontext if it is pass-by-ref. We
  			 * do not need to pfree the old transValue, since it's NULL.
  			 */
! 			MemoryContextSwitchTo(winstate->wincontext);
  			peraggstate->transValue = datumCopy(fcinfo->arg[1],
  												peraggstate->transtypeByVal,
  												peraggstate->transtypeLen);
--- 259,268 ----
  			 * already checked that the agg's input type is binary-compatible
  			 * with its transtype, so straight copy here is OK.)
  			 *
! 			 * We must copy the datum into aggcontext if it is pass-by-ref. We
  			 * do not need to pfree the old transValue, since it's NULL.
  			 */
! 			MemoryContextSwitchTo(winstate->aggcontext);
  			peraggstate->transValue = datumCopy(fcinfo->arg[1],
  												peraggstate->transtypeByVal,
  												peraggstate->transtypeLen);
***************
*** 294,300 **** advance_windowaggregate(WindowAggState *winstate,
  	newVal = FunctionCallInvoke(fcinfo);
  
  	/*
! 	 * If pass-by-ref datatype, must copy the new value into wincontext and
  	 * pfree the prior transValue.	But if transfn returned a pointer to its
  	 * first input, we don't need to do anything.
  	 */
--- 295,301 ----
  	newVal = FunctionCallInvoke(fcinfo);
  
  	/*
! 	 * If pass-by-ref datatype, must copy the new value into aggcontext and
  	 * pfree the prior transValue.	But if transfn returned a pointer to its
  	 * first input, we don't need to do anything.
  	 */
***************
*** 303,309 **** advance_windowaggregate(WindowAggState *winstate,
  	{
  		if (!fcinfo->isnull)
  		{
! 			MemoryContextSwitchTo(winstate->wincontext);
  			newVal = datumCopy(newVal,
  							   peraggstate->transtypeByVal,
  							   peraggstate->transtypeLen);
--- 304,310 ----
  	{
  		if (!fcinfo->isnull)
  		{
! 			MemoryContextSwitchTo(winstate->aggcontext);
  			newVal = datumCopy(newVal,
  							   peraggstate->transtypeByVal,
  							   peraggstate->transtypeLen);
***************
*** 391,396 **** eval_windowaggregates(WindowAggState *winstate)
--- 392,398 ----
  	MemoryContext oldContext;
  	ExprContext *econtext;
  	TupleTableSlot *agg_row_slot;
+ 	WindowObject agg_winobj;
  
  	numaggs = winstate->numaggs;
  	if (numaggs == 0)
***************
*** 398,417 **** eval_windowaggregates(WindowAggState *winstate)
  
  	/* final output execution is in ps_ExprContext */
  	econtext = winstate->ss.ps.ps_ExprContext;
  
  	/*
  	 * Currently, we support only a subset of the SQL-standard window framing
! 	 * rules.  In all the supported cases, the window frame always consists of
! 	 * a contiguous group of rows extending forward from the start of the
  	 * partition, and rows only enter the frame, never exit it, as the current
  	 * row advances forward.  This makes it possible to use an incremental
! 	 * strategy for evaluating aggregates: we run the transition function for
! 	 * each row added to the frame, and run the final function whenever we
! 	 * need the current aggregate value.  This is considerably more efficient
! 	 * than the naive approach of re-running the entire aggregate calculation
! 	 * for each current row.  It does assume that the final function doesn't
! 	 * damage the running transition value, but we have the same assumption
! 	 * in nodeAgg.c too (when it rescans an existing hash table).
  	 *
  	 * In many common cases, multiple rows share the same frame and hence the
  	 * same aggregate value. (In particular, if there's no ORDER BY in a RANGE
--- 400,426 ----
  
  	/* final output execution is in ps_ExprContext */
  	econtext = winstate->ss.ps.ps_ExprContext;
+ 	agg_winobj = winstate->agg_winobj;
+ 	agg_row_slot = winstate->agg_row_slot;
  
  	/*
  	 * Currently, we support only a subset of the SQL-standard window framing
! 	 * rules.  In some cases, the window frame always consists of a
! 	 * contiguous group of rows extending forward from the start of the
  	 * partition, and rows only enter the frame, never exit it, as the current
  	 * row advances forward.  This makes it possible to use an incremental
! 	 * strategy for evaluating aggregates rather than re-running the entire
! 	 * aggregate calculation for each row, which is more efficient.  To keep
! 	 * these cases efficient, we cannot know the frame tail bound before
! 	 * hitting it.
! 	 *
! 	 * The other cases are re-initializing aggregate on head moving.  Aside
! 	 * from the first cases, if frame head is moving and rows exit the frame
! 	 * as advancing current row, the intermediate aggregate results should
! 	 * be discarded and re-run from the head again.  'aggregatedbase' points
! 	 * to the first row where current aggregate calculation starts.  If the
! 	 * frame head doesn't move, intermediate result will be used similarly to
! 	 * the first cases.
  	 *
  	 * In many common cases, multiple rows share the same frame and hence the
  	 * same aggregate value. (In particular, if there's no ORDER BY in a RANGE
***************
*** 424,466 **** eval_windowaggregates(WindowAggState *winstate)
  	 * accumulated into the aggregate transition values.  Whenever we start a
  	 * new peer group, we accumulate forward to the end of the peer group.
  	 *
! 	 * TODO: In the future, we should implement the full SQL-standard set of
! 	 * framing rules.  We could implement the other cases by recalculating the
! 	 * aggregates whenever a row exits the frame.  That would be pretty slow,
! 	 * though.	For aggregates like SUM and COUNT we could implement a
! 	 * "negative transition function" that would be called for each row as it
! 	 * exits the frame.  We'd have to think about avoiding recalculation of
! 	 * volatile arguments of aggregate functions, too.
  	 */
  
  	/*
! 	 * If we've already aggregated up through current row, reuse the saved
! 	 * result values.  NOTE: this test works for the currently supported
! 	 * framing rules, but will need fixing when more are added.
  	 */
! 	if (winstate->aggregatedupto > winstate->currentpos)
  	{
  		for (i = 0; i < numaggs; i++)
  		{
  			peraggstate = &winstate->peragg[i];
  			wfuncno = peraggstate->wfuncno;
! 			econtext->ecxt_aggvalues[wfuncno] = peraggstate->resultValue;
! 			econtext->ecxt_aggnulls[wfuncno] = peraggstate->resultValueIsNull;
  		}
! 		return;
  	}
  
! 	/* Initialize aggregates on first call for partition */
! 	if (winstate->currentpos == 0)
  	{
  		for (i = 0; i < numaggs; i++)
  		{
  			peraggstate = &winstate->peragg[i];
  			wfuncno = peraggstate->wfuncno;
! 			initialize_windowaggregate(winstate,
! 									   &winstate->perfunc[wfuncno],
! 									   peraggstate);
  		}
  	}
  
  	/*
--- 433,517 ----
  	 * accumulated into the aggregate transition values.  Whenever we start a
  	 * new peer group, we accumulate forward to the end of the peer group.
  	 *
! 	 * TODO: In the future, we should support "negative transition function"
! 	 * to optimize the cases frame head is moving.  For aggregates like SUM
! 	 * and COUNT we could implement another function that would be called
! 	 * for each row as it exits the frame.  We'd have to think about avoiding
! 	 * recalculation of volatile arguments of aggregate functions, too.
  	 */
  
  	/*
! 	 * First, update frame positions. Aggregate framing detection is similar
! 	 * to one in window function APIs, but it optimizes it's own flow to
! 	 * detect frame head and tail, which finds the tail during aggregation
! 	 * rather than before starting. This results in tuplestore buffering
! 	 * be minimized in such simple frame like RANGE BETWEEN UNBOUNDED PRECEDING
! 	 * AND CURRENT ROW (ie default when specifying only ORDER BY clause.)
  	 */
! 	update_frameheadpos(agg_winobj, winstate->agg_row_slot);
! 
! 	/*
! 	 * Initialize aggregates on first call for partition or when some rows
! 	 * were off from frame since the last call.
! 	 */
! 	if (winstate->currentpos == 0 ||
! 		winstate->frameheadpos > winstate->aggregatedbase)
  	{
+ 		/*
+ 		 * When frame head is advancing, aggregate mark position should be
+ 		 * updated so that tuplestore can discard unnecessary rows.
+ 		 * When the condition is false (i.e. start is UNBOUNDED PRECEDING),
+ 		 * mark_ptr is invalid and we don't care about mark position.
+ 		 */
+ 		if (agg_winobj->markptr > 0)
+ 		{
+ 			if (winstate->frameheadpos < winstate->currentpos)
+ 				WinSetMarkPosition(agg_winobj, winstate->frameheadpos - 1);
+ 
+ 			/*
+ 			 * Discard current state, so that subsequent loop starts with null slot
+ 			 */
+ 			if (!TupIsNull(agg_row_slot))
+ 				ExecClearTuple(agg_row_slot);
+ 			
+ 			/*
+ 			 * reset all memory that contains aggregate transient
+ 			 * values with following pointers allocated in individual
+ 			 * functions.
+ 			 */
+ 			MemoryContextResetAndDeleteChildren(winstate->aggcontext);
+ 		}
+ 
  		for (i = 0; i < numaggs; i++)
  		{
  			peraggstate = &winstate->peragg[i];
  			wfuncno = peraggstate->wfuncno;
! 			initialize_windowaggregate(winstate,
! 									   &winstate->perfunc[wfuncno],
! 									   peraggstate);
  		}
! 
! 		winstate->aggregatedbase = winstate->frameheadpos;
! 		winstate->aggregatedupto = winstate->frameheadpos;
  	}
  
! 	/*
! 	 * If we've already aggregated up through current row and frame covers
! 	 * current row, reuse the saved result values. NOTE: this test should get
! 	 * more efficient in some framing modes.
! 	 */
! 	if (winstate->frametail_stable &&
! 		winstate->aggregatedbase <= winstate->currentpos &&
! 		winstate->aggregatedupto > winstate->currentpos)
  	{
  		for (i = 0; i < numaggs; i++)
  		{
  			peraggstate = &winstate->peragg[i];
  			wfuncno = peraggstate->wfuncno;
! 			econtext->ecxt_aggvalues[wfuncno] = peraggstate->resultValue;
! 			econtext->ecxt_aggnulls[wfuncno] = peraggstate->resultValueIsNull;
  		}
+ 		return;
  	}
  
  	/*
***************
*** 470,486 **** eval_windowaggregates(WindowAggState *winstate)
  	 * at position aggregatedupto.	The agg_ptr read pointer must always point
  	 * to the next row to read into agg_row_slot.
  	 */
- 	agg_row_slot = winstate->agg_row_slot;
  	for (;;)
  	{
  		/* Fetch next row if we didn't already */
  		if (TupIsNull(agg_row_slot))
  		{
! 			spool_tuples(winstate, winstate->aggregatedupto);
! 			tuplestore_select_read_pointer(winstate->buffer,
! 										   winstate->agg_ptr);
! 			if (!tuplestore_gettupleslot(winstate->buffer, true, true,
! 										 agg_row_slot))
  				break;			/* must be end of partition */
  		}
  
--- 521,539 ----
  	 * at position aggregatedupto.	The agg_ptr read pointer must always point
  	 * to the next row to read into agg_row_slot.
  	 */
  	for (;;)
  	{
  		/* Fetch next row if we didn't already */
  		if (TupIsNull(agg_row_slot))
  		{
! 			/*
! 			 * NOTE:
! 			 * Here window_gettupleslot() tends to fetch current row
! 			 * (but not always). We should optimize window_gettupleslot()
! 			 * on this case, where reads ahead and back currently.
! 			 */
! 			if(!window_gettupleslot(agg_winobj, winstate->aggregatedupto,
! 									agg_row_slot))
  				break;			/* must be end of partition */
  		}
  
***************
*** 544,554 **** eval_windowaggregates(WindowAggState *winstate)
  				pfree(DatumGetPointer(peraggstate->resultValue));
  
  			/*
! 			 * If pass-by-ref, copy it into our global context.
  			 */
  			if (!*isnull)
  			{
! 				oldContext = MemoryContextSwitchTo(winstate->wincontext);
  				peraggstate->resultValue =
  					datumCopy(*result,
  							  peraggstate->resulttypeByVal,
--- 597,607 ----
  				pfree(DatumGetPointer(peraggstate->resultValue));
  
  			/*
! 			 * If pass-by-ref, copy it into our aggregate context.
  			 */
  			if (!*isnull)
  			{
! 				oldContext = MemoryContextSwitchTo(winstate->aggcontext);
  				peraggstate->resultValue =
  					datumCopy(*result,
  							  peraggstate->resulttypeByVal,
***************
*** 627,634 **** begin_partition(WindowAggState *winstate)
  	winstate->frametail_valid = false;
  	winstate->spooled_rows = 0;
  	winstate->currentpos = 0;
  	winstate->frametailpos = -1;
- 	winstate->aggregatedupto = 0;
  	ExecClearTuple(winstate->agg_row_slot);
  
  	/*
--- 680,687 ----
  	winstate->frametail_valid = false;
  	winstate->spooled_rows = 0;
  	winstate->currentpos = 0;
+ 	winstate->frameheadpos = -1;
  	winstate->frametailpos = -1;
  	ExecClearTuple(winstate->agg_row_slot);
  
  	/*
***************
*** 665,671 **** begin_partition(WindowAggState *winstate)
  
  	/* create a read pointer for aggregates, if needed */
  	if (winstate->numaggs > 0)
! 		winstate->agg_ptr = tuplestore_alloc_read_pointer(winstate->buffer, 0);
  
  	/* create mark and read pointers for each real window function */
  	for (i = 0; i < numfuncs; i++)
--- 718,747 ----
  
  	/* create a read pointer for aggregates, if needed */
  	if (winstate->numaggs > 0)
! 	{
! 		WindowObject agg_winobj = winstate->agg_winobj;
! 		int			readptr_flag = 0;
! 		WindowAgg  *node = (WindowAgg *) winstate->ss.ps.plan;
! 		int			frameOptions = node->frameOptions;
! 
! 		/*
! 		 * create a read pointer for aggregate marking
! 		 * if the frame head may move
! 		 */
! 		if (!(frameOptions & FRAMEOPTION_START_UNBOUNDED_PRECEDING))
! 		{
! 			agg_winobj->markptr = tuplestore_alloc_read_pointer(winstate->buffer, 0);
! 			readptr_flag = EXEC_FLAG_BACKWARD;
! 		}
! 
! 		agg_winobj->readptr = tuplestore_alloc_read_pointer(winstate->buffer,
! 															readptr_flag);
! 
! 		agg_winobj->markpos = -1;
! 		agg_winobj->seekpos = -1;
! 		winstate->aggregatedbase = 0;
! 		winstate->aggregatedupto = 0;
! 	}
  
  	/* create mark and read pointers for each real window function */
  	for (i = 0; i < numfuncs; i++)
***************
*** 790,795 **** release_partition(WindowAggState *winstate)
--- 866,872 ----
  	 * aggregates might have allocated data we don't have direct pointers to.
  	 */
  	MemoryContextResetAndDeleteChildren(winstate->wincontext);
+ 	MemoryContextResetAndDeleteChildren(winstate->aggcontext);
  
  	if (winstate->buffer)
  		tuplestore_end(winstate->buffer);
***************
*** 814,842 **** row_is_in_frame(WindowAggState *winstate, int64 pos, TupleTableSlot *slot)
  
  	Assert(pos >= 0);			/* else caller error */
  
! 	/* We only support frame start mode UNBOUNDED PRECEDING for now */
! 	Assert(frameOptions & FRAMEOPTION_START_UNBOUNDED_PRECEDING);
  
  	/* In UNBOUNDED FOLLOWING mode, all partition rows are in frame */
  	if (frameOptions & FRAMEOPTION_END_UNBOUNDED_FOLLOWING)
  		return true;
  
! 	/* Else frame tail mode must be CURRENT ROW */
! 	Assert(frameOptions & FRAMEOPTION_END_CURRENT_ROW);
  
! 	/* if row is current row or a predecessor, it must be in frame */
! 	if (pos <= winstate->currentpos)
! 		return true;
  
! 	/* In ROWS mode, *only* such rows are in frame */
! 	if (frameOptions & FRAMEOPTION_ROWS)
! 		return false;
  
! 	/* Else must be RANGE mode */
! 	Assert(frameOptions & FRAMEOPTION_RANGE);
  
! 	/* In frame iff it's a peer of current row */
! 	return are_peers(winstate, slot, winstate->ss.ss_ScanTupleSlot);
  }
  
  /*
--- 891,1063 ----
  
  	Assert(pos >= 0);			/* else caller error */
  
! 	if (frameOptions & FRAMEOPTION_START_CURRENT_ROW)
! 	{
! 		if (frameOptions & FRAMEOPTION_ROWS)
! 		{
! 			if (pos < winstate->currentpos)
! 				return false;
! 		}
! 		else
! 		{
! 			Assert(frameOptions & FRAMEOPTION_RANGE);
! 
! 			/* preceding row that is not peer is out of frame */
! 			if (pos < winstate->currentpos &&
! 				!are_peers(winstate, slot, winstate->ss.ss_ScanTupleSlot))
! 				return false;
! 		}
! 	}
! 
! 	if (frameOptions & FRAMEOPTION_START_VALUE)
! 	{
! 		if (frameOptions & FRAMEOPTION_ROWS)
! 		{
! 			int64	offset = winstate->startRowOffset;
! 
! 			/* In ROWS mode, row within phisical offsets is in frame */
! 			if(frameOptions & FRAMEOPTION_START_VALUE_PRECEDING)
! 				offset = -offset;
! 			else
! 				Assert(frameOptions & FRAMEOPTION_START_VALUE_FOLLOWING);
! 
! 			if (pos < winstate->currentpos + offset)
! 				return false;
! 		}
! 		else
! 			elog(ERROR, "RANGE ... value PRECEDING / FOLLOWING ... is not supported");
! 	}
! 
! 	/* seems ok for starting bound up to now */
  
  	/* In UNBOUNDED FOLLOWING mode, all partition rows are in frame */
  	if (frameOptions & FRAMEOPTION_END_UNBOUNDED_FOLLOWING)
  		return true;
  
! 	if (frameOptions & FRAMEOPTION_END_CURRENT_ROW)
! 	{
! 		if (frameOptions & FRAMEOPTION_ROWS)
! 		{
! 			return (pos <= winstate->currentpos);
! 		}
! 		else
! 		{
! 			Assert(frameOptions & FRAMEOPTION_RANGE);
! 
! 			/* preceding row or peer is in frame */
! 			return pos <= winstate->currentpos ||
! 				are_peers(winstate, slot, winstate->ss.ss_ScanTupleSlot);
! 		}
! 	}
  
! 	if (frameOptions & FRAMEOPTION_END_VALUE)
! 	{
! 		if (frameOptions & FRAMEOPTION_ROWS)
! 		{
! 			int64	offset = winstate->endRowOffset;
  
! 			/* In ROWS mode, row within phisical offsets is in frame */
! 			if (frameOptions & FRAMEOPTION_END_VALUE_PRECEDING)
! 				offset = -offset;
! 			else
! 				Assert(frameOptions & FRAMEOPTION_END_VALUE_FOLLOWING);
! 
! 			return (pos <= winstate->currentpos + offset);
! 		}
! 		else
! 			elog(ERROR, "RANGE ... value PRECEDING / FOLLOWING is not supported");
! 	}
! 
! 	/* It is not supposed to reach here */
! 	elog(ERROR, "invalid frame option: %d", frameOptions);
! 
! 	return false; /* keep compiler quiet */
! }
! 
! static void
! update_frameheadpos(WindowObject winobj, TupleTableSlot *slot)
! {
! 	WindowAggState *winstate = winobj->winstate;
! 	WindowAgg  *node = (WindowAgg *) winstate->ss.ps.plan;
! 	int			frameOptions = node->frameOptions;
! 
! 	if (winstate->framehead_valid)
! 		return;
! 
! 	if (frameOptions & FRAMEOPTION_START_UNBOUNDED_PRECEDING)
! 	{
! 		winstate->frameheadpos = 0;
! 		winstate->framehead_valid = true;
! 		return;
! 	}
! 
! 	if (frameOptions & FRAMEOPTION_START_CURRENT_ROW)
! 	{
! 		int64		pos = winstate->currentpos;
! 
! 		if (frameOptions & FRAMEOPTION_ROWS)
! 		{
! 			winstate->frameheadpos = pos;
! 			winstate->framehead_valid = true;
! 			return;
! 		}
! 		Assert(frameOptions & FRAMEOPTION_RANGE);
! 
! 		if (node->ordNumCols == 0)
! 		{
! 			winstate->frameheadpos = 0;
! 			winstate->framehead_valid = true;
! 			return;
! 		}
! 		/*
! 		 * In RANGE START_CURRENT mode, frame head is
! 		 * the head row of all peers.
! 		 */
! 		for(;;)
! 		{
! 			if (!window_gettupleslot(winobj, pos, slot))
! 				break;
! 			if (!are_peers(winstate, slot,
! 						   winstate->ss.ss_ScanTupleSlot))
! 				break;
! 			pos--;
! 		}
! 		winstate->frameheadpos = pos + 1;
! 		winstate->framehead_valid = true;
! 		return;
! 	}
  
! 	if (frameOptions & FRAMEOPTION_START_VALUE)
! 	{
! 		/* In ROWS mode, frame bound is phisically n before/after current */
! 		if (frameOptions & FRAMEOPTION_ROWS)
! 		{
! 			int64	offset = winstate->startRowOffset;
! 
! 			if (frameOptions & FRAMEOPTION_START_VALUE_PRECEDING)
! 				offset = -offset;
! 			else
! 				Assert(frameOptions & FRAMEOPTION_START_VALUE_FOLLOWING);
  
! 			winstate->frameheadpos = winstate->currentpos + offset;
! 			if (offset < 0)
! 			{
! 				if (winstate->frameheadpos < 0)
! 					winstate->frameheadpos = 0;
! 			}
! 			else if (offset > 0)
! 			{
! 				/* we have to know end of the partition to cut off oveflow */
! 				spool_tuples(winstate, -1);
! 				if (winstate->frameheadpos >= winstate->spooled_rows)
! 					winstate->frameheadpos = winstate->spooled_rows - 1;
! 			}
! 			winstate->framehead_valid = true;
! 			return;
! 		}
! 		else
! 			elog(ERROR, "RAGE ... value PRECEDING / FOLLOWING is not supported");
! 	}
  }
  
  /*
***************
*** 858,866 **** update_frametailpos(WindowObject winobj, TupleTableSlot *slot)
  	if (winstate->frametail_valid)
  		return;					/* already known for current row */
  
- 	/* We only support frame start mode UNBOUNDED PRECEDING for now */
- 	Assert(frameOptions & FRAMEOPTION_START_UNBOUNDED_PRECEDING);
- 
  	/* In UNBOUNDED FOLLOWING mode, all partition rows are in frame */
  	if (frameOptions & FRAMEOPTION_END_UNBOUNDED_FOLLOWING)
  	{
--- 1079,1084 ----
***************
*** 870,916 **** update_frametailpos(WindowObject winobj, TupleTableSlot *slot)
  		return;
  	}
  
! 	/* Else frame tail mode must be CURRENT ROW */
! 	Assert(frameOptions & FRAMEOPTION_END_CURRENT_ROW);
! 
! 	/* In ROWS mode, exactly the rows up to current are in frame */
! 	if (frameOptions & FRAMEOPTION_ROWS)
  	{
! 		winstate->frametailpos = winstate->currentpos;
! 		winstate->frametail_valid = true;
! 		return;
! 	}
  
! 	/* Else must be RANGE mode */
! 	Assert(frameOptions & FRAMEOPTION_RANGE);
  
! 	/* If no ORDER BY, all rows are peers with each other */
! 	if (node->ordNumCols == 0)
! 	{
! 		spool_tuples(winstate, -1);
! 		winstate->frametailpos = winstate->spooled_rows - 1;
! 		winstate->frametail_valid = true;
! 		return;
  	}
  
! 	/*
! 	 * Else we have to search for the first non-peer of the current row. We
! 	 * assume the current value of frametailpos is a lower bound on the
! 	 * possible frame tail location, ie, frame tail never goes backward, and
! 	 * that currentpos is also a lower bound, ie, current row is always in
! 	 * frame.
! 	 */
! 	ftnext = Max(winstate->frametailpos, winstate->currentpos) + 1;
! 	for (;;)
  	{
! 		if (!window_gettupleslot(winobj, ftnext, slot))
! 			break;				/* end of partition */
! 		if (!are_peers(winstate, slot, winstate->ss.ss_ScanTupleSlot))
! 			break;				/* not peer of current row */
! 		ftnext++;
  	}
- 	winstate->frametailpos = ftnext - 1;
- 	winstate->frametail_valid = true;
  }
  
  
--- 1088,1169 ----
  		return;
  	}
  
! 	if (frameOptions & FRAMEOPTION_END_CURRENT_ROW)
  	{
! 		/* In ROWS mode, exactly the rows up to current are in frame */
! 		if (frameOptions & FRAMEOPTION_ROWS)
! 		{
! 			winstate->frametailpos = winstate->currentpos;
! 			winstate->frametail_valid = true;
! 			return;
! 		}
! 		else
! 		{
! 			/* Else must be RANGE mode */
! 			Assert(frameOptions & FRAMEOPTION_RANGE);
  
! 			/* If no ORDER BY, all rows are peers with each other */
! 			if (node->ordNumCols == 0)
! 			{
! 				spool_tuples(winstate, -1);
! 				winstate->frametailpos = winstate->spooled_rows - 1;
! 				winstate->frametail_valid = true;
! 				return;
! 			}
  
! 			/*
! 			 * Else we have to search for the first non-peer of the current row. We
! 			 * assume the current value of frametailpos is a lower bound on the
! 			 * possible frame tail location, ie, frame tail never goes backward, and
! 			 * that currentpos is also a lower bound, ie, current row is always in
! 			 * frame.
! 			 */
! 			ftnext = Max(winstate->frametailpos, winstate->currentpos) + 1;
! 			for (;;)
! 			{
! 				if (!window_gettupleslot(winobj, ftnext, slot))
! 					break;				/* end of partition */
! 				if (!are_peers(winstate, slot, winstate->ss.ss_ScanTupleSlot))
! 					break;				/* not peer of current row */
! 				ftnext++;
! 			}
! 			winstate->frametailpos = ftnext - 1;
! 			winstate->frametail_valid = true;
! 			return;
! 		}
  	}
  
! 	if (frameOptions & FRAMEOPTION_END_VALUE)
  	{
! 		/* In ROWS mode, frame bound is phisically n before/after current */
! 		if (frameOptions & FRAMEOPTION_ROWS)
! 		{
! 			int64	offset = winstate->endRowOffset;
! 
! 			if (frameOptions & FRAMEOPTION_END_VALUE_PRECEDING)
! 				offset = -offset;
! 			else
! 				Assert(frameOptions & FRAMEOPTION_END_VALUE_FOLLOWING);
! 			winstate->frametailpos = winstate->currentpos + offset;
! 
! 			if (offset < 0)
! 			{
! 				if (winstate->frametailpos < 0)
! 					winstate->frametailpos = 0;
! 			}
! 			else if (offset > 0)
! 			{
! 				/* we have to know end of the partition to cut off overflow */
! 				spool_tuples(winstate, -1);
! 				if (winstate->frametailpos >= winstate->spooled_rows)
! 					winstate->frametailpos = winstate->spooled_rows - 1;
! 			}
! 			winstate->frametail_valid = true;
! 			return;
! 		}
! 		else
! 			elog(ERROR, "RANGE ... value PRECEDING / FOLLOWING is not supported");
  	}
  }
  
  
***************
*** 953,958 **** ExecWindowAgg(WindowAggState *winstate)
--- 1206,1262 ----
  		winstate->ss.ps.ps_TupFromTlist = false;
  	}
  
+ 	if (winstate->all_first)
+ 	{
+ 		WindowAgg	   *node = (WindowAgg *) winstate->ss.ps.plan;
+ 		int				frameOptions = node->frameOptions;
+ 		ExprContext	   *econtext = winstate->ss.ps.ps_ExprContext;
+ 		Datum			value;
+ 		bool			isnull;
+ 
+ 		if (frameOptions & FRAMEOPTION_START_VALUE)
+ 		{
+ 			Assert(winstate->startOffset != NULL);
+ 			value = ExecEvalExprSwitchContext(winstate->startOffset,
+ 											  econtext,
+ 											  &isnull,
+ 											  NULL);
+ 			if (isnull)
+ 				elog(ERROR, "frame starting value must not be NULL");
+ 			if (frameOptions & FRAMEOPTION_ROWS)
+ 			{
+ 				int64	offset = DatumGetInt64(value);
+ 
+ 				if (offset < 0)
+ 					elog(ERROR, "frame starting offset must not be negative");
+ 				winstate->startRowOffset = offset;
+ 			}
+ 			else
+ 				elog(ERROR, "frame starting bound cannot be determined");
+ 		}
+ 		if (frameOptions & FRAMEOPTION_END_VALUE)
+ 		{
+ 			Assert(winstate->endOffset != NULL);
+ 			value = ExecEvalExprSwitchContext(winstate->endOffset,
+ 											  econtext,
+ 											  &isnull,
+ 											  NULL);
+ 			if (isnull)
+ 				elog(ERROR, "frame ending value must not be NULL");
+ 			if (frameOptions & FRAMEOPTION_ROWS)
+ 			{
+ 				int64	offset = DatumGetInt64(value);
+ 
+ 				if (offset < 0)
+ 					elog(ERROR, "frame ending value must not be negative");
+ 				winstate->endRowOffset = offset;
+ 			}
+ 			else
+ 				elog(ERROR, "frame ending bound cannot be determined");
+ 		}
+ 		winstate->all_first = false;
+ 	}
+ 
  restart:
  	if (winstate->buffer == NULL)
  	{
***************
*** 964,969 **** restart:
--- 1268,1274 ----
  	{
  		/* Advance current row within partition */
  		winstate->currentpos++;
+ 		winstate->framehead_valid = false;
  		/* This might mean that the frame tail moves, too */
  		winstate->frametail_valid = false;
  	}
***************
*** 1099,1112 **** ExecInitWindowAgg(WindowAgg *node, EState *estate, int eflags)
  	winstate->tmpcontext = tmpcontext;
  	ExecAssignExprContext(estate, &winstate->ss.ps);
  
! 	/* Create long-lived context for storage of aggregate transvalues etc */
  	winstate->wincontext =
  		AllocSetContextCreate(CurrentMemoryContext,
! 							  "WindowAggContext",
  							  ALLOCSET_DEFAULT_MINSIZE,
  							  ALLOCSET_DEFAULT_INITSIZE,
  							  ALLOCSET_DEFAULT_MAXSIZE);
  
  	/*
  	 * tuple table initialization
  	 */
--- 1404,1424 ----
  	winstate->tmpcontext = tmpcontext;
  	ExecAssignExprContext(estate, &winstate->ss.ps);
  
! 	/* Create long-lived context for storage of partition-local memory etc */
  	winstate->wincontext =
  		AllocSetContextCreate(CurrentMemoryContext,
! 							  "WindowAggContextWin",
  							  ALLOCSET_DEFAULT_MINSIZE,
  							  ALLOCSET_DEFAULT_INITSIZE,
  							  ALLOCSET_DEFAULT_MAXSIZE);
  
+ 	/* Create mid-lived context for aggregate trans values etc */
+ 	winstate->aggcontext =
+ 		AllocSetContextCreate(CurrentMemoryContext,
+ 							  "WindowAggContextAgg",
+ 							  ALLOCSET_DEFAULT_MINSIZE,
+ 							  ALLOCSET_DEFAULT_INITSIZE,
+ 							  ALLOCSET_DEFAULT_MAXSIZE);
  	/*
  	 * tuple table initialization
  	 */
***************
*** 1229,1235 **** ExecInitWindowAgg(WindowAgg *node, EState *estate, int eflags)
  		perfuncstate->numArguments = list_length(wfuncstate->args);
  
  		fmgr_info_cxt(wfunc->winfnoid, &perfuncstate->flinfo,
! 					  tmpcontext->ecxt_per_query_memory);
  		perfuncstate->flinfo.fn_expr = (Node *) wfunc;
  		get_typlenbyval(wfunc->wintype,
  						&perfuncstate->resulttypeLen,
--- 1541,1547 ----
  		perfuncstate->numArguments = list_length(wfuncstate->args);
  
  		fmgr_info_cxt(wfunc->winfnoid, &perfuncstate->flinfo,
! 					  econtext->ecxt_per_query_memory);
  		perfuncstate->flinfo.fn_expr = (Node *) wfunc;
  		get_typlenbyval(wfunc->wintype,
  						&perfuncstate->resulttypeLen,
***************
*** 1264,1272 **** ExecInitWindowAgg(WindowAgg *node, EState *estate, int eflags)
--- 1576,1612 ----
  	winstate->numfuncs = wfuncno + 1;
  	winstate->numaggs = aggno + 1;
  
+ 	if (winstate->numaggs > 0)
+ 	{
+ 		WindowObject agg_winobj = makeNode(WindowObjectData);
+ 
+ 		agg_winobj->winstate = winstate;
+ 		agg_winobj->argstates = NULL;
+ 		agg_winobj->localmem = NULL;
+ 		/* make sure markptr = -1 to invalidate. it may not be used */
+ 		agg_winobj->markptr = -1;
+ 		agg_winobj->readptr = -1;
+ 		winstate->agg_winobj = agg_winobj;
+ 	}
+ 
+ 	winstate->all_first = true;
  	winstate->partition_spooled = false;
  	winstate->more_partitions = false;
  
+ 	/*
+ 	 * frame stability means whether frame moves and rows are exiting.
+ 	 * this helps prediction of optimization in such like aggregates
+ 	 */
+ 	winstate->frametail_stable = !(node->frameOptions &
+ 								  (FRAMEOPTION_END_VALUE_PRECEDING |
+ 								   FRAMEOPTION_END_VALUE_FOLLOWING));
+ 
+ 	/* initialize frame bound offsets */
+ 	winstate->startOffset = ExecInitExpr((Expr *) node->startOffset,
+ 										 (PlanState *) winstate);
+ 	winstate->endOffset = ExecInitExpr((Expr *) node->endOffset,
+ 									   (PlanState *) winstate);
+ 
  	return winstate;
  }
  
***************
*** 1298,1303 **** ExecEndWindowAgg(WindowAggState *node)
--- 1638,1644 ----
  	ExecFreeExprContext(&node->ss.ps);
  
  	MemoryContextDelete(node->wincontext);
+ 	MemoryContextDelete(node->aggcontext);
  
  	outerPlan = outerPlanState(node);
  	ExecEndNode(outerPlan);
***************
*** 1315,1320 **** ExecReScanWindowAgg(WindowAggState *node, ExprContext *exprCtxt)
--- 1656,1662 ----
  	node->all_done = false;
  
  	node->ss.ps.ps_TupFromTlist = false;
+ 	node->all_first = true;
  
  	/* release tuplestore et al */
  	release_partition(node);
***************
*** 1598,1604 **** window_gettupleslot(WindowObject winobj, int64 pos, TupleTableSlot *slot)
   * API exposed to window functions
   ***********************************************************************/
  
- 
  /*
   * WinGetPartitionLocalMemory
   *		Get working memory that lives till end of partition processing
--- 1940,1945 ----
***************
*** 1749,1754 **** WinGetFuncArgInPartition(WindowObject winobj, int argno,
--- 2090,2097 ----
  						 bool *isnull, bool *isout)
  {
  	WindowAggState *winstate;
+ 	WindowAgg  *node;
+ 	int			frameOptions;
  	ExprContext *econtext;
  	TupleTableSlot *slot;
  	bool		gottuple;
***************
*** 1756,1761 **** WinGetFuncArgInPartition(WindowObject winobj, int argno,
--- 2099,2106 ----
  
  	Assert(WindowObjectIsValid(winobj));
  	winstate = winobj->winstate;
+ 	node = (WindowAgg *) winstate->ss.ps.plan;
+ 	frameOptions = node->frameOptions;
  	econtext = winstate->ss.ps.ps_ExprContext;
  	slot = winstate->temp_slot_1;
  
***************
*** 1791,1797 **** WinGetFuncArgInPartition(WindowObject winobj, int argno,
  		if (isout)
  			*isout = false;
  		if (set_mark)
! 			WinSetMarkPosition(winobj, abs_pos);
  		econtext->ecxt_outertuple = slot;
  		return ExecEvalExpr((ExprState *) list_nth(winobj->argstates, argno),
  							econtext, isnull, NULL);
--- 2136,2158 ----
  		if (isout)
  			*isout = false;
  		if (set_mark)
! 		{
! 			int64	mark_pos = abs_pos;
! 
! 			/*
! 			 * In moving RANGE frame mode, we must keep mark at
! 			 * frameheadpos - 1, since that row is to be checked
! 			 * to find frame starting boundary.
! 			 */
! 			if (!(frameOptions & FRAMEOPTION_START_UNBOUNDED_PRECEDING) &&
! 				frameOptions & FRAMEOPTION_RANGE)
! 			{
! 				update_frameheadpos(winobj, winstate->temp_slot_2);
! 				if (mark_pos >= winstate->frameheadpos)
! 					mark_pos = winstate->frameheadpos - 1;
! 			}
! 			WinSetMarkPosition(winobj, mark_pos);
! 		}
  		econtext->ecxt_outertuple = slot;
  		return ExecEvalExpr((ExprState *) list_nth(winobj->argstates, argno),
  							econtext, isnull, NULL);
***************
*** 1822,1827 **** WinGetFuncArgInFrame(WindowObject winobj, int argno,
--- 2183,2190 ----
  					 bool *isnull, bool *isout)
  {
  	WindowAggState *winstate;
+ 	WindowAgg  *node;
+ 	int			frameOptions;
  	ExprContext *econtext;
  	TupleTableSlot *slot;
  	bool		gottuple;
***************
*** 1829,1834 **** WinGetFuncArgInFrame(WindowObject winobj, int argno,
--- 2192,2199 ----
  
  	Assert(WindowObjectIsValid(winobj));
  	winstate = winobj->winstate;
+ 	node = (WindowAgg *) winstate->ss.ps.plan;
+ 	frameOptions = node->frameOptions;
  	econtext = winstate->ss.ps.ps_ExprContext;
  	slot = winstate->temp_slot_1;
  
***************
*** 1838,1844 **** WinGetFuncArgInFrame(WindowObject winobj, int argno,
  			abs_pos = winstate->currentpos + relpos;
  			break;
  		case WINDOW_SEEK_HEAD:
! 			abs_pos = relpos;
  			break;
  		case WINDOW_SEEK_TAIL:
  			update_frametailpos(winobj, slot);
--- 2203,2210 ----
  			abs_pos = winstate->currentpos + relpos;
  			break;
  		case WINDOW_SEEK_HEAD:
! 			update_frameheadpos(winobj, slot);
! 			abs_pos = winstate->frameheadpos + relpos;
  			break;
  		case WINDOW_SEEK_TAIL:
  			update_frametailpos(winobj, slot);
***************
*** 1866,1872 **** WinGetFuncArgInFrame(WindowObject winobj, int argno,
  		if (isout)
  			*isout = false;
  		if (set_mark)
! 			WinSetMarkPosition(winobj, abs_pos);
  		econtext->ecxt_outertuple = slot;
  		return ExecEvalExpr((ExprState *) list_nth(winobj->argstates, argno),
  							econtext, isnull, NULL);
--- 2232,2254 ----
  		if (isout)
  			*isout = false;
  		if (set_mark)
! 		{
! 			int64		mark_pos = abs_pos;
! 
! 			/*
! 			 * In moving RANGE frame mode, we must keep mark at
! 			 * frameheadpos - 1, since that row is to be checked
! 			 * to find frame starting boundary.
! 			 */
! 			if (!(frameOptions & FRAMEOPTION_START_UNBOUNDED_PRECEDING) &&
! 				frameOptions & FRAMEOPTION_RANGE)
! 			{
! 				update_frameheadpos(winobj, winstate->temp_slot_2);
! 				if (mark_pos >= winstate->frameheadpos)
! 					mark_pos = winstate->frameheadpos - 1;
! 			}
! 			WinSetMarkPosition(winobj, mark_pos);
! 		}
  		econtext->ecxt_outertuple = slot;
  		return ExecEvalExpr((ExprState *) list_nth(winobj->argstates, argno),
  							econtext, isnull, NULL);
*** a/src/backend/nodes/copyfuncs.c
--- b/src/backend/nodes/copyfuncs.c
***************
*** 718,723 **** _copyWindowAgg(WindowAgg *from)
--- 718,725 ----
  		COPY_POINTER_FIELD(ordOperators, from->ordNumCols * sizeof(Oid));
  	}
  	COPY_SCALAR_FIELD(frameOptions);
+ 	COPY_NODE_FIELD(startOffset);
+ 	COPY_NODE_FIELD(endOffset);
  
  	return newnode;
  }
***************
*** 1845,1850 **** _copyWindowClause(WindowClause *from)
--- 1847,1854 ----
  	COPY_NODE_FIELD(partitionClause);
  	COPY_NODE_FIELD(orderClause);
  	COPY_SCALAR_FIELD(frameOptions);
+ 	COPY_NODE_FIELD(startOffset);
+ 	COPY_NODE_FIELD(endOffset);
  	COPY_SCALAR_FIELD(winref);
  	COPY_SCALAR_FIELD(copiedOrder);
  
***************
*** 2062,2067 **** _copySortBy(SortBy *from)
--- 2066,2084 ----
  	return newnode;
  }
  
+ static WindowFrameDef *
+ _copyWindowFrameDef(WindowFrameDef *from)
+ {
+ 	WindowFrameDef *newnode = makeNode(WindowFrameDef);
+ 
+ 	COPY_SCALAR_FIELD(options);
+ 	COPY_NODE_FIELD(startOffset);
+ 	COPY_NODE_FIELD(endOffset);
+ 	COPY_LOCATION_FIELD(location);
+ 
+ 	return newnode;
+ }
+ 
  static WindowDef *
  _copyWindowDef(WindowDef *from)
  {
***************
*** 2071,2077 **** _copyWindowDef(WindowDef *from)
  	COPY_STRING_FIELD(refname);
  	COPY_NODE_FIELD(partitionClause);
  	COPY_NODE_FIELD(orderClause);
! 	COPY_SCALAR_FIELD(frameOptions);
  	COPY_LOCATION_FIELD(location);
  
  	return newnode;
--- 2088,2094 ----
  	COPY_STRING_FIELD(refname);
  	COPY_NODE_FIELD(partitionClause);
  	COPY_NODE_FIELD(orderClause);
! 	COPY_NODE_FIELD(frame);
  	COPY_LOCATION_FIELD(location);
  
  	return newnode;
***************
*** 4152,4157 **** copyObject(void *from)
--- 4169,4177 ----
  		case T_SortBy:
  			retval = _copySortBy(from);
  			break;
+ 		case T_WindowFrameDef:
+ 			retval = _copyWindowFrameDef(from);
+ 			break;
  		case T_WindowDef:
  			retval = _copyWindowDef(from);
  			break;
*** a/src/backend/nodes/equalfuncs.c
--- b/src/backend/nodes/equalfuncs.c
***************
*** 2033,2045 **** _equalSortBy(SortBy *a, SortBy *b)
  }
  
  static bool
  _equalWindowDef(WindowDef *a, WindowDef *b)
  {
  	COMPARE_STRING_FIELD(name);
  	COMPARE_STRING_FIELD(refname);
  	COMPARE_NODE_FIELD(partitionClause);
  	COMPARE_NODE_FIELD(orderClause);
! 	COMPARE_SCALAR_FIELD(frameOptions);
  	COMPARE_LOCATION_FIELD(location);
  
  	return true;
--- 2033,2055 ----
  }
  
  static bool
+ _equalWindowFrameDef(WindowFrameDef *a, WindowFrameDef *b)
+ {
+ 	COMPARE_SCALAR_FIELD(options);
+ 	COMPARE_NODE_FIELD(startOffset);
+ 	COMPARE_NODE_FIELD(endOffset);
+ 
+ 	return true;
+ }
+ 
+ static bool
  _equalWindowDef(WindowDef *a, WindowDef *b)
  {
  	COMPARE_STRING_FIELD(name);
  	COMPARE_STRING_FIELD(refname);
  	COMPARE_NODE_FIELD(partitionClause);
  	COMPARE_NODE_FIELD(orderClause);
! 	COMPARE_NODE_FIELD(frame);
  	COMPARE_LOCATION_FIELD(location);
  
  	return true;
***************
*** 2185,2190 **** _equalWindowClause(WindowClause *a, WindowClause *b)
--- 2195,2202 ----
  	COMPARE_NODE_FIELD(partitionClause);
  	COMPARE_NODE_FIELD(orderClause);
  	COMPARE_SCALAR_FIELD(frameOptions);
+ 	COMPARE_NODE_FIELD(startOffset);
+ 	COMPARE_NODE_FIELD(endOffset);
  	COMPARE_SCALAR_FIELD(winref);
  	COMPARE_SCALAR_FIELD(copiedOrder);
  
***************
*** 2845,2850 **** equal(void *a, void *b)
--- 2857,2865 ----
  		case T_SortBy:
  			retval = _equalSortBy(a, b);
  			break;
+ 		case T_WindowFrameDef:
+ 			retval = _equalWindowFrameDef(a, b);
+ 			break;
  		case T_WindowDef:
  			retval = _equalWindowDef(a, b);
  			break;
*** a/src/backend/nodes/outfuncs.c
--- b/src/backend/nodes/outfuncs.c
***************
*** 610,615 **** _outWindowAgg(StringInfo str, WindowAgg *node)
--- 610,617 ----
  		appendStringInfo(str, " %u", node->ordOperators[i]);
  
  	WRITE_INT_FIELD(frameOptions);
+ 	WRITE_NODE_FIELD(startOffset);
+ 	WRITE_NODE_FIELD(endOffset);
  }
  
  static void
***************
*** 2026,2032 **** _outWindowClause(StringInfo str, WindowClause *node)
  	WRITE_STRING_FIELD(refname);
  	WRITE_NODE_FIELD(partitionClause);
  	WRITE_NODE_FIELD(orderClause);
! 	WRITE_INT_FIELD(frameOptions);
  	WRITE_UINT_FIELD(winref);
  	WRITE_BOOL_FIELD(copiedOrder);
  }
--- 2028,2036 ----
  	WRITE_STRING_FIELD(refname);
  	WRITE_NODE_FIELD(partitionClause);
  	WRITE_NODE_FIELD(orderClause);
! 	WRITE_UINT_FIELD(frameOptions);
! 	WRITE_NODE_FIELD(startOffset);
! 	WRITE_NODE_FIELD(endOffset);
  	WRITE_UINT_FIELD(winref);
  	WRITE_BOOL_FIELD(copiedOrder);
  }
***************
*** 2309,2314 **** _outSortBy(StringInfo str, SortBy *node)
--- 2313,2328 ----
  }
  
  static void
+ _outWindowFrameDef(StringInfo str, WindowFrameDef *node)
+ {
+ 	WRITE_NODE_TYPE("WINDOWFRAMEDEF");
+ 
+ 	WRITE_INT_FIELD(options);
+ 	WRITE_NODE_FIELD(startOffset);
+ 	WRITE_NODE_FIELD(endOffset);
+ }
+ 
+ static void
  _outWindowDef(StringInfo str, WindowDef *node)
  {
  	WRITE_NODE_TYPE("WINDOWDEF");
***************
*** 2317,2323 **** _outWindowDef(StringInfo str, WindowDef *node)
  	WRITE_STRING_FIELD(refname);
  	WRITE_NODE_FIELD(partitionClause);
  	WRITE_NODE_FIELD(orderClause);
! 	WRITE_INT_FIELD(frameOptions);
  	WRITE_LOCATION_FIELD(location);
  }
  
--- 2331,2337 ----
  	WRITE_STRING_FIELD(refname);
  	WRITE_NODE_FIELD(partitionClause);
  	WRITE_NODE_FIELD(orderClause);
! 	WRITE_NODE_FIELD(frame);
  	WRITE_LOCATION_FIELD(location);
  }
  
***************
*** 2850,2855 **** _outNode(StringInfo str, void *obj)
--- 2864,2872 ----
  			case T_SortBy:
  				_outSortBy(str, obj);
  				break;
+ 			case T_WindowFrameDef:
+ 				_outWindowFrameDef(str, obj);
+ 				break;
  			case T_WindowDef:
  				_outWindowDef(str, obj);
  				break;
*** a/src/backend/nodes/readfuncs.c
--- b/src/backend/nodes/readfuncs.c
***************
*** 278,284 **** _readWindowClause(void)
  	READ_STRING_FIELD(refname);
  	READ_NODE_FIELD(partitionClause);
  	READ_NODE_FIELD(orderClause);
! 	READ_INT_FIELD(frameOptions);
  	READ_UINT_FIELD(winref);
  	READ_BOOL_FIELD(copiedOrder);
  
--- 278,286 ----
  	READ_STRING_FIELD(refname);
  	READ_NODE_FIELD(partitionClause);
  	READ_NODE_FIELD(orderClause);
! 	READ_UINT_FIELD(frameOptions);
! 	READ_NODE_FIELD(startOffset);
! 	READ_NODE_FIELD(endOffset);
  	READ_UINT_FIELD(winref);
  	READ_BOOL_FIELD(copiedOrder);
  
*** a/src/backend/optimizer/plan/createplan.c
--- b/src/backend/optimizer/plan/createplan.c
***************
*** 3354,3360 **** make_windowagg(PlannerInfo *root, List *tlist,
  			   int numWindowFuncs, Index winref,
  			   int partNumCols, AttrNumber *partColIdx, Oid *partOperators,
  			   int ordNumCols, AttrNumber *ordColIdx, Oid *ordOperators,
! 			   int frameOptions, Plan *lefttree)
  {
  	WindowAgg  *node = makeNode(WindowAgg);
  	Plan	   *plan = &node->plan;
--- 3354,3361 ----
  			   int numWindowFuncs, Index winref,
  			   int partNumCols, AttrNumber *partColIdx, Oid *partOperators,
  			   int ordNumCols, AttrNumber *ordColIdx, Oid *ordOperators,
! 			   int frameOptions, Node *startOffset, Node *endOffset,
! 			   Plan *lefttree)
  {
  	WindowAgg  *node = makeNode(WindowAgg);
  	Plan	   *plan = &node->plan;
***************
*** 3369,3374 **** make_windowagg(PlannerInfo *root, List *tlist,
--- 3370,3377 ----
  	node->ordColIdx = ordColIdx;
  	node->ordOperators = ordOperators;
  	node->frameOptions = frameOptions;
+ 	node->startOffset = startOffset;
+ 	node->endOffset = endOffset;
  
  	copy_plan_costsize(plan, lefttree); /* only care about copying size */
  	cost_windowagg(&windowagg_path, root,
*** a/src/backend/optimizer/plan/planner.c
--- b/src/backend/optimizer/plan/planner.c
***************
*** 1480,1490 **** grouping_planner(PlannerInfo *root, double tuple_fraction)
  					window_tlist = tlist;
  				}
  
  				/* ... and make the WindowAgg plan node */
  				result_plan = (Plan *)
  					make_windowagg(root,
  								   (List *) copyObject(window_tlist),
! 							   list_length(wflists->windowFuncs[wc->winref]),
  								   wc->winref,
  								   partNumCols,
  								   partColIdx,
--- 1480,1494 ----
  					window_tlist = tlist;
  				}
  
+ 				wc->startOffset = preprocess_expression(root, wc->startOffset,
+ 														EXPRKIND_LIMIT);
+ 				wc->endOffset = preprocess_expression(root, wc->endOffset,
+ 													  EXPRKIND_LIMIT);
  				/* ... and make the WindowAgg plan node */
  				result_plan = (Plan *)
  					make_windowagg(root,
  								   (List *) copyObject(window_tlist),
! 								   list_length(wflists->windowFuncs[wc->winref]),
  								   wc->winref,
  								   partNumCols,
  								   partColIdx,
***************
*** 1493,1498 **** grouping_planner(PlannerInfo *root, double tuple_fraction)
--- 1497,1504 ----
  								   ordColIdx,
  								   ordOperators,
  								   wc->frameOptions,
+ 								   wc->startOffset,
+ 								   wc->endOffset,
  								   result_plan);
  			}
  		}
*** a/src/backend/optimizer/plan/setrefs.c
--- b/src/backend/optimizer/plan/setrefs.c
***************
*** 465,472 **** set_plan_refs(PlannerGlobal *glob, Plan *plan, int rtoffset)
  					fix_scan_expr(glob, splan->limitCount, rtoffset);
  			}
  			break;
- 		case T_Agg:
  		case T_WindowAgg:
  		case T_Group:
  			set_upper_references(glob, plan, rtoffset);
  			break;
--- 465,488 ----
  					fix_scan_expr(glob, splan->limitCount, rtoffset);
  			}
  			break;
  		case T_WindowAgg:
+ 			{
+ 				WindowAgg	   *splan = (WindowAgg *) plan;
+ 
+ 				/*
+ 				 * Like Limit node limit/offset expressions, WindowAgg has
+ 				 * frame offset expressions which cannot contain subplan
+ 				 * variable refs, so fix_scan_expr works for them.
+ 				 */
+ 				splan->startOffset =
+ 					fix_scan_expr(glob, splan->startOffset, rtoffset);
+ 				splan->endOffset =
+ 					fix_scan_expr(glob, splan->endOffset, rtoffset);
+ 
+ 				set_upper_references(glob, plan, rtoffset);
+ 			}
+ 			break;
+ 		case T_Agg:
  		case T_Group:
  			set_upper_references(glob, plan, rtoffset);
  			break;
*** a/src/backend/optimizer/plan/subselect.c
--- b/src/backend/optimizer/plan/subselect.c
***************
*** 2087,2095 **** finalize_plan(PlannerInfo *root, Plan *plan, Bitmapset *valid_params,
  										 locally_added_param);
  			break;
  
  		case T_Hash:
  		case T_Agg:
- 		case T_WindowAgg:
  		case T_Material:
  		case T_Sort:
  		case T_Unique:
--- 2087,2101 ----
  										 locally_added_param);
  			break;
  
+ 		case T_WindowAgg:
+ 			finalize_primnode(((WindowAgg *) plan)->startOffset,
+ 							  &context);
+ 			finalize_primnode(((WindowAgg *) plan)->endOffset,
+ 							  &context);
+ 			break;
+ 
  		case T_Hash:
  		case T_Agg:
  		case T_Material:
  		case T_Sort:
  		case T_Unique:
*** a/src/backend/parser/gram.y
--- b/src/backend/parser/gram.y
***************
*** 430,436 **** static TypeName *TableFuncTypeName(List *columns);
  %type <list>	window_clause window_definition_list opt_partition_clause
  %type <windef>	window_definition over_clause window_specification
  %type <str>		opt_existing_window_name
! %type <ival>	opt_frame_clause frame_extent frame_bound
  
  
  /*
--- 430,436 ----
  %type <list>	window_clause window_definition_list opt_partition_clause
  %type <windef>	window_definition over_clause window_specification
  %type <str>		opt_existing_window_name
! %type <node>	opt_frame_clause frame_extent frame_bound
  
  
  /*
***************
*** 564,569 **** static TypeName *TableFuncTypeName(List *columns);
--- 564,570 ----
  %nonassoc	BETWEEN
  %nonassoc	IN_P
  %left		POSTFIXOP		/* dummy for postfix Op rules */
+ %nonassoc	UNBOUNDED		/* needed for frame_extend, frame_bound */
  /*
   * To support target_el without AS, we must give IDENT an explicit priority
   * between POSTFIXOP and Op.  We can safely assign the same priority to
***************
*** 574,580 **** static TypeName *TableFuncTypeName(List *columns);
   * so that they can follow a_expr without creating
   * postfix-operator problems.
   */
! %nonassoc	IDENT PARTITION RANGE ROWS
  %left		Op OPERATOR		/* multi-character ops and user-defined operators */
  %nonassoc	NOTNULL
  %nonassoc	ISNULL
--- 575,581 ----
   * so that they can follow a_expr without creating
   * postfix-operator problems.
   */
! %nonassoc	IDENT PARTITION RANGE ROWS PRECEDING FOLLOWING
  %left		Op OPERATOR		/* multi-character ops and user-defined operators */
  %nonassoc	NOTNULL
  %nonassoc	ISNULL
***************
*** 9735,9745 **** over_clause: OVER window_specification
  			| OVER ColId
  				{
  					WindowDef *n = makeNode(WindowDef);
  					n->name = $2;
  					n->refname = NULL;
  					n->partitionClause = NIL;
  					n->orderClause = NIL;
! 					n->frameOptions = FRAMEOPTION_DEFAULTS;
  					n->location = @2;
  					$$ = n;
  				}
--- 9736,9750 ----
  			| OVER ColId
  				{
  					WindowDef *n = makeNode(WindowDef);
+ 					WindowFrameDef *frame = makeNode(WindowFrameDef);
+ 					frame->options = FRAMEOPTION_DEFAULTS;
+ 					frame->startOffset = NULL;
+ 					frame->endOffset = NULL;
  					n->name = $2;
  					n->refname = NULL;
  					n->partitionClause = NIL;
  					n->orderClause = NIL;
! 					n->frame = frame;
  					n->location = @2;
  					$$ = n;
  				}
***************
*** 9755,9761 **** window_specification: '(' opt_existing_window_name opt_partition_clause
  					n->refname = $2;
  					n->partitionClause = $3;
  					n->orderClause = $4;
! 					n->frameOptions = $5;
  					n->location = @1;
  					$$ = n;
  				}
--- 9760,9766 ----
  					n->refname = $2;
  					n->partitionClause = $3;
  					n->orderClause = $4;
! 					n->frame = (WindowFrameDef *) $5;
  					n->location = @1;
  					$$ = n;
  				}
***************
*** 9787,9837 **** opt_partition_clause: PARTITION BY expr_list		{ $$ = $3; }
  opt_frame_clause:
  			RANGE frame_extent
  				{
! 					$$ = FRAMEOPTION_NONDEFAULT | FRAMEOPTION_RANGE | $2;
  				}
  			| ROWS frame_extent
  				{
! 					$$ = FRAMEOPTION_NONDEFAULT | FRAMEOPTION_ROWS | $2;
  				}
  			| /*EMPTY*/
! 				{ $$ = FRAMEOPTION_DEFAULTS; }
  		;
  
  frame_extent: frame_bound
  				{
  					/* reject invalid cases */
! 					if ($1 & FRAMEOPTION_START_UNBOUNDED_FOLLOWING)
  						ereport(ERROR,
  								(errcode(ERRCODE_WINDOWING_ERROR),
  								 errmsg("frame start cannot be UNBOUNDED FOLLOWING"),
  								 parser_errposition(@1)));
! 					if ($1 & FRAMEOPTION_START_CURRENT_ROW)
  						ereport(ERROR,
! 								(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
! 								 errmsg("frame start at CURRENT ROW is not implemented"),
  								 parser_errposition(@1)));
! 					$$ = $1 | FRAMEOPTION_END_CURRENT_ROW;
  				}
  			| BETWEEN frame_bound AND frame_bound
  				{
  					/* reject invalid cases */
! 					if ($2 & FRAMEOPTION_START_UNBOUNDED_FOLLOWING)
  						ereport(ERROR,
  								(errcode(ERRCODE_WINDOWING_ERROR),
  								 errmsg("frame start cannot be UNBOUNDED FOLLOWING"),
  								 parser_errposition(@2)));
! 					if ($2 & FRAMEOPTION_START_CURRENT_ROW)
! 						ereport(ERROR,
! 								(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
! 								 errmsg("frame start at CURRENT ROW is not implemented"),
! 								 parser_errposition(@2)));
! 					if ($4 & FRAMEOPTION_START_UNBOUNDED_PRECEDING)
  						ereport(ERROR,
  								(errcode(ERRCODE_WINDOWING_ERROR),
  								 errmsg("frame end cannot be UNBOUNDED PRECEDING"),
  								 parser_errposition(@4)));
  					/* shift converts START_ options to END_ options */
! 					$$ = FRAMEOPTION_BETWEEN | $2 | ($4 << 1);
  				}
  		;
  
--- 9792,9881 ----
  opt_frame_clause:
  			RANGE frame_extent
  				{
! 					WindowFrameDef *frame = (WindowFrameDef *) $2;
! 					frame->options |= FRAMEOPTION_NONDEFAULT | FRAMEOPTION_RANGE;
! 					frame->location = @1;
! 					$$ = (Node *) frame;
  				}
  			| ROWS frame_extent
  				{
! 					WindowFrameDef *frame = (WindowFrameDef *) $2;
! 					frame->options |= FRAMEOPTION_NONDEFAULT | FRAMEOPTION_ROWS;
! 					frame->location = @1;
! 					$$ = (Node *) frame;
  				}
  			| /*EMPTY*/
! 				{
! 					WindowFrameDef *frame = makeNode(WindowFrameDef);
! 					frame->options = FRAMEOPTION_DEFAULTS;
! 					frame->startOffset = NULL;
! 					frame->endOffset = NULL;
! 					frame->location = -1;
! 					$$ = (Node *) frame;
! 				}
  		;
  
  frame_extent: frame_bound
  				{
+ 					WindowFrameDef *frame = (WindowFrameDef *) $1;
  					/* reject invalid cases */
! 					if (frame->options & FRAMEOPTION_START_UNBOUNDED_FOLLOWING)
  						ereport(ERROR,
  								(errcode(ERRCODE_WINDOWING_ERROR),
  								 errmsg("frame start cannot be UNBOUNDED FOLLOWING"),
  								 parser_errposition(@1)));
! 					if (frame->options & FRAMEOPTION_START_VALUE_FOLLOWING)
  						ereport(ERROR,
! 								(errcode(ERRCODE_WINDOWING_ERROR),
! 								 errmsg("frame from following row cannot end with current row"),
  								 parser_errposition(@1)));
! 					frame->options |= FRAMEOPTION_END_CURRENT_ROW;
! 					$$ = (Node *) frame;
  				}
  			| BETWEEN frame_bound AND frame_bound
  				{
+ 					WindowFrameDef *frame1 = (WindowFrameDef *) $2;
+ 					WindowFrameDef *frame2 = (WindowFrameDef *) $4;
  					/* reject invalid cases */
! 					if (frame1->options & FRAMEOPTION_START_UNBOUNDED_FOLLOWING)
  						ereport(ERROR,
  								(errcode(ERRCODE_WINDOWING_ERROR),
  								 errmsg("frame start cannot be UNBOUNDED FOLLOWING"),
  								 parser_errposition(@2)));
! 					if (frame2->options & FRAMEOPTION_START_UNBOUNDED_PRECEDING)
  						ereport(ERROR,
  								(errcode(ERRCODE_WINDOWING_ERROR),
  								 errmsg("frame end cannot be UNBOUNDED PRECEDING"),
  								 parser_errposition(@4)));
+ 					if (frame1->options & FRAMEOPTION_START_CURRENT_ROW &&
+ 						frame2->options &
+ 							(FRAMEOPTION_START_UNBOUNDED_PRECEDING |
+ 							 FRAMEOPTION_START_VALUE_PRECEDING))
+ 						ereport(ERROR,
+ 								(errcode(ERRCODE_WINDOWING_ERROR),
+ 								 errmsg("frame from current row cannot have preceding rows"),
+ 								 parser_errposition(@4)));
+ 					if (frame1->options & FRAMEOPTION_START_VALUE_FOLLOWING &&
+ 						frame2->options &
+ 							(FRAMEOPTION_START_VALUE_PRECEDING |
+ 							 FRAMEOPTION_START_CURRENT_ROW))
+ 						ereport(ERROR,
+ 								(errcode(ERRCODE_WINDOWING_ERROR),
+ 								 errmsg("frame from following row cannot have preceding rows"),
+ 								 parser_errposition(@4)));
+ 					if (frame1->options & FRAMEOPTION_START_VALUE_FOLLOWING &&
+ 						frame2->options & FRAMEOPTION_END_VALUE_PRECEDING)
+ 						ereport(ERROR,
+ 								(errcode(ERRCODE_WINDOWING_ERROR),
+ 								 errmsg("frame cannot be BETWEEN x FOLLOWING AND y PRECEDING"),
+ 								 parser_errposition(@1)));
  					/* shift converts START_ options to END_ options */
! 					frame1->options |= frame2->options << 1;
! 					frame1->options |= FRAMEOPTION_BETWEEN;
! 					frame1->endOffset = frame2->startOffset;
! 					/* frame2 is not necessary anymore */
! 					pfree(frame2);
! 					$$ = (Node *) frame1;
  				}
  		;
  
***************
*** 9839,9857 **** frame_extent: frame_bound
   * This is used for both frame start and frame end, with output set up on
   * the assumption it's frame start; the frame_extent productions must reject
   * invalid cases.
   */
  frame_bound:
  			UNBOUNDED PRECEDING
  				{
! 					$$ = FRAMEOPTION_START_UNBOUNDED_PRECEDING;
  				}
  			| UNBOUNDED FOLLOWING
  				{
! 					$$ = FRAMEOPTION_START_UNBOUNDED_FOLLOWING;
  				}
  			| CURRENT_P ROW
  				{
! 					$$ = FRAMEOPTION_START_CURRENT_ROW;
  				}
  		;
  
--- 9883,9931 ----
   * This is used for both frame start and frame end, with output set up on
   * the assumption it's frame start; the frame_extent productions must reject
   * invalid cases.
+  *
+  * Since UNBOUNDED is an unreserved keyword, it could possibly be an a_expr.
+  * We fix that by making UNBOUNDED have slightly lower precedence than the
+  * lookahead tokens PRECEDING and FOLLOWING.  This solution might cause
+  * strange behavior if UNBOUNDED is ever used anyplace else in the grammar,
+  * however.
   */
  frame_bound:
  			UNBOUNDED PRECEDING
  				{
! 					WindowFrameDef *frame = makeNode(WindowFrameDef);
! 					frame->options = FRAMEOPTION_START_UNBOUNDED_PRECEDING;
! 					frame->startOffset = NULL;
! 					frame->endOffset = NULL;
! 					$$ = (Node *) frame;
  				}
  			| UNBOUNDED FOLLOWING
  				{
! 					WindowFrameDef *frame = makeNode(WindowFrameDef);
! 					frame->options = FRAMEOPTION_START_UNBOUNDED_FOLLOWING;
! 					frame->startOffset = NULL;
! 					frame->endOffset = NULL;
! 					$$ = (Node *) frame;
  				}
  			| CURRENT_P ROW
  				{
! 					WindowFrameDef *frame = makeNode(WindowFrameDef);
! 					frame->options = FRAMEOPTION_START_CURRENT_ROW;
! 					$$ = (Node *) frame;
! 				}
! 			| a_expr PRECEDING
! 				{
! 					WindowFrameDef *frame = makeNode(WindowFrameDef);
! 					frame->options = FRAMEOPTION_START_VALUE_PRECEDING;
! 					frame->startOffset = $1;
! 					$$ = (Node *) frame;
! 				}
! 			| a_expr FOLLOWING
! 				{
! 					WindowFrameDef *frame = makeNode(WindowFrameDef);
! 					frame->options = FRAMEOPTION_START_VALUE_FOLLOWING;
! 					frame->startOffset = $1;
! 					$$ = (Node *) frame;
  				}
  		;
  
***************
*** 10809,10815 **** unreserved_keyword:
   * looks too much like a function call for an LR(1) parser.
   */
  col_name_keyword:
! 			  BIGINT
  			| BIT
  			| BOOLEAN_P
  			| CHAR_P
--- 10883,10890 ----
   * looks too much like a function call for an LR(1) parser.
   */
  col_name_keyword:
! 			  BETWEEN
! 			| BIGINT
  			| BIT
  			| BOOLEAN_P
  			| CHAR_P
***************
*** 10868,10874 **** col_name_keyword:
   */
  type_func_name_keyword:
  			  AUTHORIZATION
- 			| BETWEEN
  			| BINARY
  			| CROSS
  			| CURRENT_SCHEMA
--- 10943,10948 ----
*** a/src/backend/parser/parse_agg.c
--- b/src/backend/parser/parse_agg.c
***************
*** 136,142 **** transformWindowFuncCall(ParseState *pstate, WindowFunc *wfunc,
  		Assert(windef->refname == NULL &&
  			   windef->partitionClause == NIL &&
  			   windef->orderClause == NIL &&
! 			   windef->frameOptions == FRAMEOPTION_DEFAULTS);
  
  		foreach(lc, pstate->p_windowdefs)
  		{
--- 136,142 ----
  		Assert(windef->refname == NULL &&
  			   windef->partitionClause == NIL &&
  			   windef->orderClause == NIL &&
! 			   windef->frame->options == FRAMEOPTION_DEFAULTS);
  
  		foreach(lc, pstate->p_windowdefs)
  		{
***************
*** 174,180 **** transformWindowFuncCall(ParseState *pstate, WindowFunc *wfunc,
  				continue;
  			if (equal(refwin->partitionClause, windef->partitionClause) &&
  				equal(refwin->orderClause, windef->orderClause) &&
! 				refwin->frameOptions == windef->frameOptions)
  			{
  				/* found a duplicate window specification */
  				wfunc->winref = winref;
--- 174,180 ----
  				continue;
  			if (equal(refwin->partitionClause, windef->partitionClause) &&
  				equal(refwin->orderClause, windef->orderClause) &&
! 				equal(refwin->frame, windef->frame))
  			{
  				/* found a duplicate window specification */
  				wfunc->winref = winref;
*** a/src/backend/parser/parse_clause.c
--- b/src/backend/parser/parse_clause.c
***************
*** 85,91 **** static List *addTargetToGroupList(ParseState *pstate, TargetEntry *tle,
  					 List *grouplist, List *targetlist, int location,
  					 bool resolveUnknown);
  static WindowClause *findWindowClause(List *wclist, const char *name);
! 
  
  /*
   * transformFromClause -
--- 85,94 ----
  					 List *grouplist, List *targetlist, int location,
  					 bool resolveUnknown);
  static WindowClause *findWindowClause(List *wclist, const char *name);
! static Node *transformFrameOffset(ParseState *pstate, int frameOptions,
! 								  Node *clause, const char *constructName);
! static void checkExprIsLevelStable(ParseState *pstate, Node *n,
! 								   const char *constructName);
  
  /*
   * transformFromClause -
***************
*** 1177,1217 **** transformLimitClause(ParseState *pstate, Node *clause,
  
  	qual = coerce_to_specific_type(pstate, qual, INT8OID, constructName);
  
! 	/*
! 	 * LIMIT can't refer to any vars or aggregates of the current query
! 	 */
! 	if (contain_vars_of_level(qual, 0))
! 	{
! 		ereport(ERROR,
! 				(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
! 		/* translator: %s is name of a SQL construct, eg LIMIT */
! 				 errmsg("argument of %s must not contain variables",
! 						constructName),
! 				 parser_errposition(pstate,
! 									locate_var_of_level(qual, 0))));
! 	}
! 	if (pstate->p_hasAggs &&
! 		checkExprHasAggs(qual))
! 	{
! 		ereport(ERROR,
! 				(errcode(ERRCODE_GROUPING_ERROR),
! 		/* translator: %s is name of a SQL construct, eg LIMIT */
! 				 errmsg("argument of %s must not contain aggregate functions",
! 						constructName),
! 				 parser_errposition(pstate,
! 									locate_agg_of_level(qual, 0))));
! 	}
! 	if (pstate->p_hasWindowFuncs &&
! 		checkExprHasWindowFuncs(qual))
! 	{
! 		ereport(ERROR,
! 				(errcode(ERRCODE_WINDOWING_ERROR),
! 		/* translator: %s is name of a SQL construct, eg LIMIT */
! 				 errmsg("argument of %s must not contain window functions",
! 						constructName),
! 				 parser_errposition(pstate,
! 									locate_windowfunc(qual))));
! 	}
  
  	return qual;
  }
--- 1180,1186 ----
  
  	qual = coerce_to_specific_type(pstate, qual, INT8OID, constructName);
  
! 	checkExprIsLevelStable(pstate, qual, constructName);
  
  	return qual;
  }
***************
*** 1663,1669 **** transformWindowDefinitions(ParseState *pstate,
  					 errmsg("cannot override frame clause of window \"%s\"",
  							windef->refname),
  					 parser_errposition(pstate, windef->location)));
! 		wc->frameOptions = windef->frameOptions;
  		wc->winref = winref;
  
  		result = lappend(result, wc);
--- 1632,1644 ----
  					 errmsg("cannot override frame clause of window \"%s\"",
  							windef->refname),
  					 parser_errposition(pstate, windef->location)));
! 		wc->frameOptions = windef->frame->options;
! 		wc->startOffset = transformFrameOffset(pstate, windef->frame->options,
! 											   windef->frame->startOffset,
! 											   "Frame Start Offset");
! 		wc->endOffset = transformFrameOffset(pstate, windef->frame->options,
! 											 windef->frame->endOffset,
! 											 "Frame End Offset");
  		wc->winref = winref;
  
  		result = lappend(result, wc);
***************
*** 2160,2162 **** findWindowClause(List *wclist, const char *name)
--- 2135,2206 ----
  
  	return NULL;
  }
+ 
+ /*
+  *	transformFrameOffset
+  */
+ static Node *
+ transformFrameOffset(ParseState *pstate, int frameOptions, Node *clause,
+ 					 const char *constructName)
+ {
+ 	Node	   *node;
+ 
+ 	if (clause == NULL)
+ 		return NULL;
+ 
+ 	node = transformExpr(pstate, clause);
+ 	if (frameOptions & FRAMEOPTION_ROWS)
+ 		node = coerce_to_specific_type(pstate, node, INT8OID, constructName);
+ 	else
+ 	{
+ 		Assert(frameOptions & FRAMEOPTION_RANGE);
+ 		elog(ERROR, "ERROR on parsing frame clause");
+ 	}
+ 	checkExprIsLevelStable(pstate, node, constructName);
+ 
+ 	return node;
+ }
+ 
+ /*
+  * checkExprIsLevelStable
+  *		Check if given expr is stable value in the current query level.
+  *		This check prevent use of any local vars, aggregates or window
+  *		functions in the expression.
+  */
+ static void
+ checkExprIsLevelStable(ParseState *pstate, Node *n,
+ 					   const char *constructName)
+ {
+ 	if (contain_vars_of_level(n, 0))
+ 	{
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
+ 		/* translator: %s is name of a SQL construct, eg LIMIT */
+ 				 errmsg("argument of %s must not contain variables",
+ 						constructName),
+ 				 parser_errposition(pstate,
+ 									locate_var_of_level(n, 0))));
+ 	}
+ 	if (pstate->p_hasAggs &&
+ 		checkExprHasAggs(n))
+ 	{
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_GROUPING_ERROR),
+ 		/* translator: %s is name of a SQL construct, eg LIMIT */
+ 				 errmsg("argument of %s must not contain aggregate functions",
+ 						constructName),
+ 				 parser_errposition(pstate,
+ 									locate_agg_of_level(n, 0))));
+ 	}
+ 	if (pstate->p_hasWindowFuncs &&
+ 		checkExprHasWindowFuncs(n))
+ 	{
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_WINDOWING_ERROR),
+ 		/* translator: %s is name of a SQL construct, eg LIMIT */
+ 				 errmsg("argument of %s must not contain window functions",
+ 						constructName),
+ 				 parser_errposition(pstate,
+ 									locate_windowfunc(n))));
+ 	}
+ }
*** a/src/backend/utils/adt/array_userfuncs.c
--- b/src/backend/utils/adt/array_userfuncs.c
***************
*** 487,493 **** array_agg_transfn(PG_FUNCTION_ARGS)
  	if (fcinfo->context && IsA(fcinfo->context, AggState))
  		aggcontext = ((AggState *) fcinfo->context)->aggcontext;
  	else if (fcinfo->context && IsA(fcinfo->context, WindowAggState))
! 		aggcontext = ((WindowAggState *) fcinfo->context)->wincontext;
  	else
  	{
  		/* cannot be called directly because of internal-type argument */
--- 487,493 ----
  	if (fcinfo->context && IsA(fcinfo->context, AggState))
  		aggcontext = ((AggState *) fcinfo->context)->aggcontext;
  	else if (fcinfo->context && IsA(fcinfo->context, WindowAggState))
! 		aggcontext = ((WindowAggState *) fcinfo->context)->aggcontext;
  	else
  	{
  		/* cannot be called directly because of internal-type argument */
*** a/src/backend/utils/adt/ruleutils.c
--- b/src/backend/utils/adt/ruleutils.c
***************
*** 3089,3094 **** get_rule_windowspec(WindowClause *wc, List *targetList,
--- 3089,3104 ----
  			appendStringInfoString(buf, "UNBOUNDED PRECEDING ");
  		else if (wc->frameOptions & FRAMEOPTION_START_CURRENT_ROW)
  			appendStringInfoString(buf, "CURRENT ROW ");
+ 		else if (wc->frameOptions & FRAMEOPTION_START_VALUE)
+ 		{
+ 			get_rule_expr(wc->startOffset, context, true);
+ 			if (wc->frameOptions & FRAMEOPTION_START_VALUE_PRECEDING)
+ 				appendStringInfoString(buf, " PRECEDING ");
+ 			else if (wc->frameOptions & FRAMEOPTION_START_VALUE_FOLLOWING)
+ 				appendStringInfoString(buf, " FOLLOWING ");
+ 			else
+ 				Assert(false);
+ 		}
  		else
  			Assert(false);
  		if (wc->frameOptions & FRAMEOPTION_BETWEEN)
***************
*** 3098,3103 **** get_rule_windowspec(WindowClause *wc, List *targetList,
--- 3108,3123 ----
  				appendStringInfoString(buf, "UNBOUNDED FOLLOWING ");
  			else if (wc->frameOptions & FRAMEOPTION_END_CURRENT_ROW)
  				appendStringInfoString(buf, "CURRENT ROW ");
+ 			else if(wc->frameOptions & FRAMEOPTION_END_VALUE)
+ 			{
+ 				get_rule_expr(wc->endOffset, context, true);
+ 				if (wc->frameOptions & FRAMEOPTION_END_VALUE_PRECEDING)
+ 					appendStringInfoString(buf, " PRECEDING ");
+ 				else if (wc->frameOptions & FRAMEOPTION_END_VALUE_FOLLOWING)
+ 					appendStringInfoString(buf, " FOLLOWING ");
+ 				else
+ 					Assert(false);
+ 			}
  			else
  				Assert(false);
  		}
*** a/src/include/nodes/execnodes.h
--- b/src/include/nodes/execnodes.h
***************
*** 14,19 ****
--- 14,20 ----
  #ifndef EXECNODES_H
  #define EXECNODES_H
  
+ #include "windowapi.h"
  #include "access/genam.h"
  #include "access/heapam.h"
  #include "access/skey.h"
***************
*** 1588,1610 **** typedef struct WindowAggState
  	FmgrInfo   *ordEqfunctions; /* equality funcs for ordering columns */
  	Tuplestorestate *buffer;	/* stores rows of current partition */
  	int			current_ptr;	/* read pointer # for current */
- 	int			agg_ptr;		/* read pointer # for aggregates */
  	int64		spooled_rows;	/* total # of rows in buffer */
  	int64		currentpos;		/* position of current row in partition */
  	int64		frametailpos;	/* current frame tail position */
  	int64		aggregatedupto; /* rows before this one are aggregated */
  
  	MemoryContext wincontext;	/* context for partition-lifespan data */
  	ExprContext *tmpcontext;	/* short-term evaluation context */
  
  	bool		all_done;		/* true if the scan is finished */
  	bool		partition_spooled;		/* true if all tuples in current
  										 * partition have been spooled into
  										 * tuplestore */
  	bool		more_partitions;/* true if there's more partitions after this
  								 * one */
  	bool		frametail_valid;/* true if frametailpos is known up to date
  								 * for current row */
  
  	TupleTableSlot *first_part_slot;	/* first tuple of current or next
  										 * partition */
--- 1589,1623 ----
  	FmgrInfo   *ordEqfunctions; /* equality funcs for ordering columns */
  	Tuplestorestate *buffer;	/* stores rows of current partition */
  	int			current_ptr;	/* read pointer # for current */
  	int64		spooled_rows;	/* total # of rows in buffer */
  	int64		currentpos;		/* position of current row in partition */
+ 	int64		frameheadpos;	/* current frame head position */
  	int64		frametailpos;	/* current frame tail position */
+ 	WindowObject agg_winobj;	/* window to track moving frame in aggregates */
+ 	int64		aggregatedbase; /* row position this aggregate started on */
  	int64		aggregatedupto; /* rows before this one are aggregated */
  
+ 	ExprState  *startOffset;
+ 	ExprState  *endOffset;
+ 	int64		startRowOffset;	/* In ROWS mode, upper offset from current */
+ 	int64		endRowOffset;	/* In ROWS mode, lower offset from current */
+ 
  	MemoryContext wincontext;	/* context for partition-lifespan data */
+ 	MemoryContext aggcontext;	/* context for each aggregate data */
  	ExprContext *tmpcontext;	/* short-term evaluation context */
  
+ 	bool		all_first;		/* true if the scan is starting */
  	bool		all_done;		/* true if the scan is finished */
  	bool		partition_spooled;		/* true if all tuples in current
  										 * partition have been spooled into
  										 * tuplestore */
  	bool		more_partitions;/* true if there's more partitions after this
  								 * one */
+ 	bool		framehead_valid;/* true if frameheadpos is known up to date
+ 								 * for current row */
  	bool		frametail_valid;/* true if frametailpos is known up to date
  								 * for current row */
+ 	bool		frametail_stable;	/* frame's tail doesn't move */
  
  	TupleTableSlot *first_part_slot;	/* first tuple of current or next
  										 * partition */
*** a/src/include/nodes/nodes.h
--- b/src/include/nodes/nodes.h
***************
*** 362,367 **** typedef enum NodeTag
--- 362,368 ----
  	T_ResTarget,
  	T_TypeCast,
  	T_SortBy,
+ 	T_WindowFrameDef,
  	T_WindowDef,
  	T_RangeSubselect,
  	T_RangeFunction,
*** a/src/include/nodes/parsenodes.h
--- b/src/include/nodes/parsenodes.h
***************
*** 376,381 **** typedef struct SortBy
--- 376,393 ----
  } SortBy;
  
  /*
+  * WindowFrameDef - for FRAME clause description in WINDOW definition
+  */
+ typedef struct WindowFrameDef
+ {
+ 	NodeTag		type;
+ 	int			options;		/* frame_clause options, see below */
+ 	Node	   *startOffset;	/* how far is the starting bound */
+ 	Node	   *endOffset;		/* how far is the ending bound */
+ 	int			location;		/* parse location, or -1 if none/unknown */
+ } WindowFrameDef;
+ 
+ /*
   * WindowDef - raw representation of WINDOW and OVER clauses
   *
   * For entries in a WINDOW list, "name" is the window name being defined.
***************
*** 390,396 **** typedef struct WindowDef
  	char	   *refname;		/* referenced window name, if any */
  	List	   *partitionClause;	/* PARTITION BY expression list */
  	List	   *orderClause;	/* ORDER BY (list of SortBy) */
! 	int			frameOptions;	/* frame_clause options, see below */
  	int			location;		/* parse location, or -1 if none/unknown */
  } WindowDef;
  
--- 402,408 ----
  	char	   *refname;		/* referenced window name, if any */
  	List	   *partitionClause;	/* PARTITION BY expression list */
  	List	   *orderClause;	/* ORDER BY (list of SortBy) */
! 	WindowFrameDef *frame;		/* FRAME clause including boundary values */
  	int			location;		/* parse location, or -1 if none/unknown */
  } WindowDef;
  
***************
*** 412,422 **** typedef struct WindowDef
--- 424,443 ----
  #define FRAMEOPTION_END_UNBOUNDED_FOLLOWING		0x00080 /* end is U. F. */
  #define FRAMEOPTION_START_CURRENT_ROW			0x00100 /* start is C. R. */
  #define FRAMEOPTION_END_CURRENT_ROW				0x00200 /* end is C. R. */
+ #define FRAMEOPTION_START_VALUE_PRECEDING		0x01000 /* start is V. P. */
+ #define FRAMEOPTION_END_VALUE_PRECEDING			0x02000 /* end is V.P. */
+ #define FRAMEOPTION_START_VALUE_FOLLOWING		0x04000 /* start is V. F. */
+ #define FRAMEOPTION_END_VALUE_FOLLOWING			0x08000 /* end is V. F. */
  
  #define FRAMEOPTION_DEFAULTS \
  	(FRAMEOPTION_RANGE | FRAMEOPTION_START_UNBOUNDED_PRECEDING | \
  	 FRAMEOPTION_END_CURRENT_ROW)
  
+ #define FRAMEOPTION_START_VALUE \
+ 	(FRAMEOPTION_START_VALUE_PRECEDING | FRAMEOPTION_START_VALUE_FOLLOWING)
+ #define FRAMEOPTION_END_VALUE \
+ 	(FRAMEOPTION_END_VALUE_PRECEDING | FRAMEOPTION_END_VALUE_FOLLOWING)
+ 
  /*
   * RangeSubselect - subquery appearing in a FROM clause
   */
***************
*** 795,800 **** typedef struct WindowClause
--- 816,823 ----
  	List	   *partitionClause;	/* PARTITION BY list */
  	List	   *orderClause;	/* ORDER BY list */
  	int			frameOptions;	/* frame_clause options, see WindowDef */
+ 	Node	   *startOffset;	/* offset value to start frame */
+ 	Node	   *endOffset;		/* offset value to end frame */
  	Index		winref;			/* ID referenced by window functions */
  	bool		copiedOrder;	/* did we copy orderClause from refname? */
  } WindowClause;
*** a/src/include/nodes/plannodes.h
--- b/src/include/nodes/plannodes.h
***************
*** 552,557 **** typedef struct WindowAgg
--- 552,559 ----
  	AttrNumber *ordColIdx;		/* their indexes in the target list */
  	Oid		   *ordOperators;	/* equality operators for ordering columns */
  	int			frameOptions;	/* frame_clause options, see WindowDef */
+ 	Node	   *startOffset;	/* frame start boundary */
+ 	Node	   *endOffset;		/* frame end boundary */
  } WindowAgg;
  
  /* ----------------
*** a/src/include/optimizer/planmain.h
--- b/src/include/optimizer/planmain.h
***************
*** 61,67 **** extern WindowAgg *make_windowagg(PlannerInfo *root, List *tlist,
  			   int numWindowFuncs, Index winref,
  			   int partNumCols, AttrNumber *partColIdx, Oid *partOperators,
  			   int ordNumCols, AttrNumber *ordColIdx, Oid *ordOperators,
! 			   int frameOptions, Plan *lefttree);
  extern Group *make_group(PlannerInfo *root, List *tlist, List *qual,
  		   int numGroupCols, AttrNumber *grpColIdx, Oid *grpOperators,
  		   double numGroups,
--- 61,68 ----
  			   int numWindowFuncs, Index winref,
  			   int partNumCols, AttrNumber *partColIdx, Oid *partOperators,
  			   int ordNumCols, AttrNumber *ordColIdx, Oid *ordOperators,
! 			   int frameOptions, Node *startOffset, Node *endOffset,
! 			   Plan *lefttree);
  extern Group *make_group(PlannerInfo *root, List *tlist, List *qual,
  		   int numGroupCols, AttrNumber *grpColIdx, Oid *grpOperators,
  		   double numGroups,
*** a/src/include/parser/kwlist.h
--- b/src/include/parser/kwlist.h
***************
*** 53,59 **** PG_KEYWORD("authorization", AUTHORIZATION, TYPE_FUNC_NAME_KEYWORD)
  PG_KEYWORD("backward", BACKWARD, UNRESERVED_KEYWORD)
  PG_KEYWORD("before", BEFORE, UNRESERVED_KEYWORD)
  PG_KEYWORD("begin", BEGIN_P, UNRESERVED_KEYWORD)
! PG_KEYWORD("between", BETWEEN, TYPE_FUNC_NAME_KEYWORD)
  PG_KEYWORD("bigint", BIGINT, COL_NAME_KEYWORD)
  PG_KEYWORD("binary", BINARY, TYPE_FUNC_NAME_KEYWORD)
  PG_KEYWORD("bit", BIT, COL_NAME_KEYWORD)
--- 53,59 ----
  PG_KEYWORD("backward", BACKWARD, UNRESERVED_KEYWORD)
  PG_KEYWORD("before", BEFORE, UNRESERVED_KEYWORD)
  PG_KEYWORD("begin", BEGIN_P, UNRESERVED_KEYWORD)
! PG_KEYWORD("between", BETWEEN, COL_NAME_KEYWORD)
  PG_KEYWORD("bigint", BIGINT, COL_NAME_KEYWORD)
  PG_KEYWORD("binary", BINARY, TYPE_FUNC_NAME_KEYWORD)
  PG_KEYWORD("bit", BIT, COL_NAME_KEYWORD)
*** a/src/test/regress/expected/window.out
--- b/src/test/regress/expected/window.out
***************
*** 728,733 **** FROM (select distinct ten, four from tenk1) ss;
--- 728,908 ----
      3 |   2 |   4 |          2
  (20 rows)
  
+ SELECT sum(unique1) over (order by four range between current row and unbounded following),
+ 	unique1, four
+ FROM tenk1 WHERE unique1 < 10;
+  sum | unique1 | four 
+ -----+---------+------
+   45 |       0 |    0
+   45 |       8 |    0
+   45 |       4 |    0
+   33 |       5 |    1
+   33 |       9 |    1
+   33 |       1 |    1
+   18 |       6 |    2
+   18 |       2 |    2
+   10 |       3 |    3
+   10 |       7 |    3
+ (10 rows)
+ 
+ SELECT sum(unique1) over (rows between current row and unbounded following),
+ 	unique1, four
+ FROM tenk1 WHERE unique1 < 10;
+  sum | unique1 | four 
+ -----+---------+------
+   45 |       4 |    0
+   41 |       2 |    2
+   39 |       1 |    1
+   38 |       6 |    2
+   32 |       9 |    1
+   23 |       8 |    0
+   15 |       5 |    1
+   10 |       3 |    3
+    7 |       7 |    3
+    0 |       0 |    0
+ (10 rows)
+ 
+ SELECT sum(unique1) over (rows between 2 preceding and 2 following),
+ 	unique1, four
+ FROM tenk1 WHERE unique1 < 10;
+  sum | unique1 | four 
+ -----+---------+------
+    7 |       4 |    0
+   13 |       2 |    2
+   22 |       1 |    1
+   26 |       6 |    2
+   29 |       9 |    1
+   31 |       8 |    0
+   32 |       5 |    1
+   23 |       3 |    3
+   15 |       7 |    3
+   10 |       0 |    0
+ (10 rows)
+ 
+ SELECT sum(unique1) over (rows between 2 preceding and 1 preceding),
+ 	unique1, four
+ FROM tenk1 WHERE unique1 < 10;
+  sum | unique1 | four 
+ -----+---------+------
+      |       4 |    0
+    4 |       2 |    2
+    6 |       1 |    1
+    3 |       6 |    2
+    7 |       9 |    1
+   15 |       8 |    0
+   17 |       5 |    1
+   13 |       3 |    3
+    8 |       7 |    3
+   10 |       0 |    0
+ (10 rows)
+ 
+ SELECT sum(unique1) over (rows between 1 following and 3 following),
+ 	unique1, four
+ FROM tenk1 WHERE unique1 < 10;
+  sum | unique1 | four 
+ -----+---------+------
+    9 |       4 |    0
+   16 |       2 |    2
+   23 |       1 |    1
+   22 |       6 |    2
+   16 |       9 |    1
+   15 |       8 |    0
+   10 |       5 |    1
+    7 |       3 |    3
+    0 |       7 |    3
+    0 |       0 |    0
+ (10 rows)
+ 
+ SELECT sum(unique1) over (rows between unbounded preceding and 1 following),
+ 	unique1, four
+ FROM tenk1 WHERE unique1 < 10;
+  sum | unique1 | four 
+ -----+---------+------
+    6 |       4 |    0
+    7 |       2 |    2
+   13 |       1 |    1
+   22 |       6 |    2
+   30 |       9 |    1
+   35 |       8 |    0
+   38 |       5 |    1
+   45 |       3 |    3
+   45 |       7 |    3
+   45 |       0 |    0
+ (10 rows)
+ 
+ SELECT sum(unique1) over (w range between current row and unbounded following),
+ 	unique1, four
+ FROM tenk1 WHERE unique1 < 10 WINDOW w AS (order by four);
+  sum | unique1 | four 
+ -----+---------+------
+   45 |       0 |    0
+   45 |       8 |    0
+   45 |       4 |    0
+   33 |       5 |    1
+   33 |       9 |    1
+   33 |       1 |    1
+   18 |       6 |    2
+   18 |       2 |    2
+   10 |       3 |    3
+   10 |       7 |    3
+ (10 rows)
+ 
+ SELECT first_value(unique1) over w,
+ 	nth_value(unique1, 2) over w AS nth_2,
+ 	last_value(unique1) over w, unique1, four
+ FROM tenk1 WHERE unique1 < 10
+ WINDOW w AS (order by four range between current row and unbounded following);
+  first_value | nth_2 | last_value | unique1 | four 
+ -------------+-------+------------+---------+------
+            0 |     8 |          7 |       0 |    0
+            0 |     8 |          7 |       8 |    0
+            0 |     8 |          7 |       4 |    0
+            5 |     9 |          7 |       5 |    1
+            5 |     9 |          7 |       9 |    1
+            5 |     9 |          7 |       1 |    1
+            6 |     2 |          7 |       6 |    2
+            6 |     2 |          7 |       2 |    2
+            3 |     7 |          7 |       3 |    3
+            3 |     7 |          7 |       7 |    3
+ (10 rows)
+ 
+ SELECT sum(unique1) over
+ 	(rows (SELECT unique1 FROM tenk1 ORDER BY unique1 LIMIT 1) + 1 PRECEDING),
+ 	unique1
+ FROM tenk1 where unique1 < 10;
+  sum | unique1 
+ -----+---------
+    4 |       4
+    6 |       2
+    3 |       1
+    7 |       6
+   15 |       9
+   17 |       8
+   13 |       5
+    8 |       3
+   10 |       7
+    7 |       0
+ (10 rows)
+ 
+ CREATE VIEW v AS
+ 	SELECT i, sum(i) over (order by i rows between 1 preceding and 1 following)
+ 	FROM generate_series(1, 10) i;
+ SELECT * FROM v;
+  i  | sum 
+ ----+-----
+   1 |   3
+   2 |   6
+   3 |   9
+   4 |  12
+   5 |  15
+   6 |  18
+   7 |  21
+   8 |  24
+   9 |  27
+  10 |  19
+ (10 rows)
+ 
+ DROP VIEW v;
  -- with UNION
  SELECT count(*) OVER (PARTITION BY four) FROM (SELECT * FROM tenk1 UNION ALL SELECT * FROM tenk2)s LIMIT 0;
   count 
*** a/src/test/regress/sql/window.sql
--- b/src/test/regress/sql/window.sql
***************
*** 161,166 **** SELECT four, ten/4 as two,
--- 161,211 ----
  	last_value(ten/4) over (partition by four order by ten/4 rows between unbounded preceding and current row)
  FROM (select distinct ten, four from tenk1) ss;
  
+ SELECT sum(unique1) over (order by four range between current row and unbounded following),
+ 	unique1, four
+ FROM tenk1 WHERE unique1 < 10;
+ 
+ SELECT sum(unique1) over (rows between current row and unbounded following),
+ 	unique1, four
+ FROM tenk1 WHERE unique1 < 10;
+ 
+ SELECT sum(unique1) over (rows between 2 preceding and 2 following),
+ 	unique1, four
+ FROM tenk1 WHERE unique1 < 10;
+ 
+ SELECT sum(unique1) over (rows between 2 preceding and 1 preceding),
+ 	unique1, four
+ FROM tenk1 WHERE unique1 < 10;
+ 
+ SELECT sum(unique1) over (rows between 1 following and 3 following),
+ 	unique1, four
+ FROM tenk1 WHERE unique1 < 10;
+ 
+ SELECT sum(unique1) over (rows between unbounded preceding and 1 following),
+ 	unique1, four
+ FROM tenk1 WHERE unique1 < 10;
+ 
+ SELECT sum(unique1) over (w range between current row and unbounded following),
+ 	unique1, four
+ FROM tenk1 WHERE unique1 < 10 WINDOW w AS (order by four);
+ 
+ SELECT first_value(unique1) over w,
+ 	nth_value(unique1, 2) over w AS nth_2,
+ 	last_value(unique1) over w, unique1, four
+ FROM tenk1 WHERE unique1 < 10
+ WINDOW w AS (order by four range between current row and unbounded following);
+ 
+ SELECT sum(unique1) over
+ 	(rows (SELECT unique1 FROM tenk1 ORDER BY unique1 LIMIT 1) + 1 PRECEDING),
+ 	unique1
+ FROM tenk1 where unique1 < 10;
+ 
+ CREATE VIEW v AS
+ 	SELECT i, sum(i) over (order by i rows between 1 preceding and 1 following)
+ 	FROM generate_series(1, 10) i;
+ SELECT * FROM v;
+ DROP VIEW v;
+ 
  -- with UNION
  SELECT count(*) OVER (PARTITION BY four) FROM (SELECT * FROM tenk1 UNION ALL SELECT * FROM tenk2)s LIMIT 0;