autovac_truncate.patch

diff --git a/src/backend/commands/vacuumlazy.c b/src/backend/commands/vacuumlazy.c
new file mode 100644
index 0401b7f..fda2656
*** a/src/backend/commands/vacuumlazy.c
--- b/src/backend/commands/vacuumlazy.c
***************
*** 75,83 ****
   * that the potential for improvement was great enough to merit the cost of
   * supporting them.
   */
! #define AUTOVACUUM_TRUNCATE_LOCK_CHECK_INTERVAL		20	/* ms */
! #define AUTOVACUUM_TRUNCATE_LOCK_WAIT_INTERVAL		50	/* ms */
! #define AUTOVACUUM_TRUNCATE_LOCK_TIMEOUT			5000		/* ms */
  
  /*
   * Guesstimation of number of dead tuples per page.  This is used to
--- 75,83 ----
   * that the potential for improvement was great enough to merit the cost of
   * supporting them.
   */
! #define VACUUM_TRUNCATE_LOCK_CHECK_INTERVAL		20	/* ms */
! #define VACUUM_TRUNCATE_LOCK_WAIT_INTERVAL		50	/* ms */
! #define VACUUM_TRUNCATE_LOCK_TIMEOUT			5000		/* ms */
  
  /*
   * Guesstimation of number of dead tuples per page.  This is used to
*************** lazy_truncate_heap(Relation onerel, LVRe
*** 1306,1313 ****
  			 */
  			CHECK_FOR_INTERRUPTS();
  
! 			if (++lock_retry > (AUTOVACUUM_TRUNCATE_LOCK_TIMEOUT /
! 								AUTOVACUUM_TRUNCATE_LOCK_WAIT_INTERVAL))
  			{
  				/*
  				 * We failed to establish the lock in the specified number of
--- 1306,1313 ----
  			 */
  			CHECK_FOR_INTERRUPTS();
  
! 			if (++lock_retry > (VACUUM_TRUNCATE_LOCK_TIMEOUT /
! 								VACUUM_TRUNCATE_LOCK_WAIT_INTERVAL))
  			{
  				/*
  				 * We failed to establish the lock in the specified number of
*************** lazy_truncate_heap(Relation onerel, LVRe
*** 1318,1333 ****
  				 */
  				vacrelstats->lock_waiter_detected = true;
  				ereport(LOG,
! 						(errmsg("automatic vacuum of table \"%s.%s.%s\": "
  								"could not (re)acquire exclusive "
! 								"lock for truncate scan",
  								get_database_name(MyDatabaseId),
  							get_namespace_name(RelationGetNamespace(onerel)),
! 								RelationGetRelationName(onerel))));
  				return;
  			}
  
! 			pg_usleep(AUTOVACUUM_TRUNCATE_LOCK_WAIT_INTERVAL);
  		}
  
  		/*
--- 1318,1334 ----
  				 */
  				vacrelstats->lock_waiter_detected = true;
  				ereport(LOG,
! 						(errmsg("vacuum of table \"%s.%s.%s\": "
  								"could not (re)acquire exclusive "
! 								"lock for truncate scan (%d pages already truncated)",
  								get_database_name(MyDatabaseId),
  							get_namespace_name(RelationGetNamespace(onerel)),
! 								RelationGetRelationName(onerel),
! 								vacrelstats->pages_removed)));
  				return;
  			}
  
! 			pg_usleep(VACUUM_TRUNCATE_LOCK_WAIT_INTERVAL);
  		}
  
  		/*
*************** count_nondeletable_pages(Relation onerel
*** 1437,1443 ****
  			elapsed = currenttime;
  			INSTR_TIME_SUBTRACT(elapsed, starttime);
  			if ((INSTR_TIME_GET_MICROSEC(elapsed) / 1000)
! 				>= AUTOVACUUM_TRUNCATE_LOCK_CHECK_INTERVAL)
  			{
  				if (LockHasWaitersRelation(onerel, AccessExclusiveLock))
  				{
--- 1438,1444 ----
  			elapsed = currenttime;
  			INSTR_TIME_SUBTRACT(elapsed, starttime);
  			if ((INSTR_TIME_GET_MICROSEC(elapsed) / 1000)
! 				>= VACUUM_TRUNCATE_LOCK_CHECK_INTERVAL)
  			{
  				if (LockHasWaitersRelation(onerel, AccessExclusiveLock))
  				{