diff -cr pgsql/contrib/pgstattuple/pgstattuple.c pgsql_work/contrib/pgstattuple/pgstattuple.c
*** pgsql/contrib/pgstattuple/pgstattuple.c	2009-06-11 23:48:52.000000000 +0900
--- pgsql_work/contrib/pgstattuple/pgstattuple.c	2010-04-02 18:52:05.000000000 +0900
***************
*** 276,281 ****
--- 276,283 ----
  	/* scan the relation */
  	while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
  	{
+ 		CHECK_FOR_INTERRUPTS();
+ 
  		/* must hold a buffer lock to call HeapTupleSatisfiesVisibility */
  		LockBuffer(scan->rs_cbuf, BUFFER_LOCK_SHARE);
  
***************
*** 302,307 ****
--- 304,311 ----
  
  		while (block <= tupblock)
  		{
+ 			CHECK_FOR_INTERRUPTS();
+ 
  			buffer = ReadBuffer(rel, block);
  			LockBuffer(buffer, BUFFER_LOCK_SHARE);
  			stat.free_space += PageGetHeapFreeSpace((Page) BufferGetPage(buffer));
***************
*** 313,318 ****
--- 317,324 ----
  
  	while (block < nblocks)
  	{
+ 		CHECK_FOR_INTERRUPTS();
+ 
  		buffer = ReadBuffer(rel, block);
  		LockBuffer(buffer, BUFFER_LOCK_SHARE);
  		stat.free_space += PageGetHeapFreeSpace((Page) BufferGetPage(buffer));
***************
*** 454,459 ****
--- 460,467 ----
  	blkno = start;
  	for (;;)
  	{
+ 		CHECK_FOR_INTERRUPTS();
+ 
  		/* Get the current relation length */
  		LockRelationForExtension(rel, ExclusiveLock);
  		nblocks = RelationGetNumberOfBlocks(rel);