*** a/src/backend/commands/vacuumlazy.c
--- b/src/backend/commands/vacuumlazy.c
***************
*** 185,190 **** lazy_vacuum_rel(Relation onerel, VacuumStmt *vacstmt,
--- 185,195 ----
  	BlockNumber new_rel_allvisible;
  	TransactionId new_frozen_xid;
  	MultiXactId new_min_multi;
+ 	PgStat_StatTabEntry *tabentry = NULL;
+ 	int64		dead_tuples = 0;
+ 	int64		new_dead_tuples = 0;
+ 
+ 
  
  	/* measure elapsed time iff autovacuum logging requires it */
  	if (IsAutoVacuumWorkerProcess() && Log_autovacuum_min_duration >= 0)
***************
*** 215,220 **** lazy_vacuum_rel(Relation onerel, VacuumStmt *vacstmt,
--- 220,235 ----
  	vacrelstats->pages_removed = 0;
  	vacrelstats->lock_waiter_detected = false;
  
+ 	/*
+ 	 * Get the data in the table's hashtable entry.
+ 	 */
+ 	if (IsAutoVacuumWorkerProcess())
+ 	{
+ 		tabentry = pgstat_fetch_stat_tabentry(RelationGetRelid(onerel));
+ 		if (tabentry != NULL)
+ 			dead_tuples = tabentry->n_dead_tuples;
+ 	}
+ 
  	/* Open all indexes of the relation */
  	vac_open_indexes(onerel, RowExclusiveLock, &nindexes, &Irel);
  	vacrelstats->hasindex = (nindexes > 0);
***************
*** 285,294 **** lazy_vacuum_rel(Relation onerel, VacuumStmt *vacstmt,
  						new_frozen_xid,
  						new_min_multi);
  
  	/* report results to the stats collector, too */
  	pgstat_report_vacuum(RelationGetRelid(onerel),
  						 onerel->rd_rel->relisshared,
! 						 new_rel_tuples);
  
  	/* and log the action if appropriate */
  	if (IsAutoVacuumWorkerProcess() && Log_autovacuum_min_duration >= 0)
--- 300,320 ----
  						new_frozen_xid,
  						new_min_multi);
  
+ 	/* calculate the number of new dead tuples */
+ 	if (IsAutoVacuumWorkerProcess())
+ 	{
+ 		/* clear and get the new stats for calculating proper dead tuples */
+ 		pgstat_clear_snapshot();
+ 		tabentry = pgstat_fetch_stat_tabentry(RelationGetRelid(onerel));
+ 		if (tabentry != NULL)
+ 			new_dead_tuples = tabentry->n_dead_tuples - dead_tuples;
+ 	}
+ 
  	/* report results to the stats collector, too */
  	pgstat_report_vacuum(RelationGetRelid(onerel),
  						 onerel->rd_rel->relisshared,
! 						 new_rel_tuples,
! 						 new_dead_tuples);
  
  	/* and log the action if appropriate */
  	if (IsAutoVacuumWorkerProcess() && Log_autovacuum_min_duration >= 0)
*** a/src/backend/postmaster/pgstat.c
--- b/src/backend/postmaster/pgstat.c
***************
*** 1317,1323 **** pgstat_report_autovac(Oid dboid)
   * ---------
   */
  void
! pgstat_report_vacuum(Oid tableoid, bool shared, PgStat_Counter tuples)
  {
  	PgStat_MsgVacuum msg;
  
--- 1317,1324 ----
   * ---------
   */
  void
! pgstat_report_vacuum(Oid tableoid, bool shared, PgStat_Counter tuples,
! 					 PgStat_Counter dead_tuples)
  {
  	PgStat_MsgVacuum msg;
  
***************
*** 1330,1335 **** pgstat_report_vacuum(Oid tableoid, bool shared, PgStat_Counter tuples)
--- 1331,1337 ----
  	msg.m_autovacuum = IsAutoVacuumWorkerProcess();
  	msg.m_vacuumtime = GetCurrentTimestamp();
  	msg.m_tuples = tuples;
+ 	msg.m_dead_tuples = dead_tuples;
  	pgstat_send(&msg, sizeof(msg));
  }
  
***************
*** 4800,4807 **** pgstat_recv_vacuum(PgStat_MsgVacuum *msg, int len)
  	tabentry = pgstat_get_tab_entry(dbentry, msg->m_tableoid, true);
  
  	tabentry->n_live_tuples = msg->m_tuples;
! 	/* Resetting dead_tuples to 0 is an approximation ... */
! 	tabentry->n_dead_tuples = 0;
  
  	if (msg->m_autovacuum)
  	{
--- 4802,4808 ----
  	tabentry = pgstat_get_tab_entry(dbentry, msg->m_tableoid, true);
  
  	tabentry->n_live_tuples = msg->m_tuples;
! 	tabentry->n_dead_tuples = msg->m_dead_tuples;
  
  	if (msg->m_autovacuum)
  	{
*** a/src/include/pgstat.h
--- b/src/include/pgstat.h
***************
*** 332,337 **** typedef struct PgStat_MsgVacuum
--- 332,338 ----
  	bool		m_autovacuum;
  	TimestampTz m_vacuumtime;
  	PgStat_Counter m_tuples;
+ 	PgStat_Counter m_dead_tuples;
  } PgStat_MsgVacuum;
  
  
***************
*** 773,779 **** extern void pgstat_reset_single_counter(Oid objectid, PgStat_Single_Reset_Type t
  
  extern void pgstat_report_autovac(Oid dboid);
  extern void pgstat_report_vacuum(Oid tableoid, bool shared,
! 					 PgStat_Counter tuples);
  extern void pgstat_report_analyze(Relation rel,
  					  PgStat_Counter livetuples, PgStat_Counter deadtuples);
  
--- 774,780 ----
  
  extern void pgstat_report_autovac(Oid dboid);
  extern void pgstat_report_vacuum(Oid tableoid, bool shared,
! 					 PgStat_Counter tuples, PgStat_Counter dead_tuples);
  extern void pgstat_report_analyze(Relation rel,
  					  PgStat_Counter livetuples, PgStat_Counter deadtuples);