diff --git a/src/backend/commands/resgroupcmds.c b/src/backend/commands/resgroupcmds.c
index fdf93564b4df79326a35a5b3c69a5a88097af507..9a4de023ac3bcda2f815311c711af32d97df1253 100644
--- a/src/backend/commands/resgroupcmds.c
+++ b/src/backend/commands/resgroupcmds.c
@@ -59,7 +59,7 @@
 #define RESGROUP_MAX_MEMORY_SHARED_QUOTA	(100)
 
 #define RESGROUP_MIN_MEMORY_SPILL_RATIO		(0)
-#define RESGROUP_MAX_MEMORY_SPILL_RATIO		(100)
+#define RESGROUP_MAX_MEMORY_SPILL_RATIO		(INT_MAX)
 
 /*
  * The names must be in the same order as ResGroupMemAuditorType.
diff --git a/src/backend/utils/misc/guc_gp.c b/src/backend/utils/misc/guc_gp.c
index cd8a618445763b0a878a1c4aa2c4d9a6146b2b3d..654e8bbed156380757ee6e1e8a66b7850084c006 100644
--- a/src/backend/utils/misc/guc_gp.c
+++ b/src/backend/utils/misc/guc_gp.c
@@ -2974,7 +2974,7 @@ struct config_int ConfigureNamesInt_gp[] =
 			NULL
 		},
 		&memory_spill_ratio,
-		20, 0, 100, NULL, NULL
+		20, 0, INT_MAX, NULL, NULL
 	},
 
 	{
diff --git a/src/backend/utils/resgroup/resgroup.c b/src/backend/utils/resgroup/resgroup.c
index 968a209a9ec35fc4357202b0b4e73f04e11a87f5..577e969d11b9f1586e9bcdf98fb8148e8634ba25 100644
--- a/src/backend/utils/resgroup/resgroup.c
+++ b/src/backend/utils/resgroup/resgroup.c
@@ -169,7 +169,7 @@ struct ResGroupData
 {
 	Oid			groupId;		/* Id for this group */
 	ResGroupCaps	caps;		/* capabilities of this group */
-	int			nRunning;		/* number of running trans */
+	volatile int			nRunning;		/* number of running trans */
 	PROC_QUEUE	waitProcs;		/* list of PGPROC objects waiting on this group */
 	int			totalExecuted;	/* total number of executed trans */
 	int			totalQueued;	/* total number of queued trans	*/
@@ -191,15 +191,15 @@ struct ResGroupData
 	int32		memQuotaGranted;	/* memory chunks for quota part */
 	int32		memSharedGranted;	/* memory chunks for shared part */
 
-	int32		memQuotaUsed;		/* memory chunks assigned to all the running slots */
+	volatile int32	memQuotaUsed;	/* memory chunks assigned to all the running slots */
 
 	/*
 	 * memory usage of this group, should always equal to the
 	 * sum of session memory(session_state->sessionVmem) that
 	 * belongs to this group
 	 */
-	int32		memUsage;
-	int32		memSharedUsage;
+	volatile int32	memUsage;
+	volatile int32	memSharedUsage;
 
 	/*
 	 * operation functions for resource group
@@ -219,7 +219,9 @@ struct ResGroupControl
 	bool			loaded;
 
 	int32			totalChunks;	/* total memory chunks on this segment */
-	int32			freeChunks;		/* memory chunks not allocated to any group */
+	volatile int32	freeChunks;		/* memory chunks not allocated to any group,
+									will be used for the query which group share
+									memory is not enough*/
 
 	int32			chunkSizeInBits;
 
@@ -279,9 +281,9 @@ static void groupReleaseMemQuota(ResGroupData *group, ResGroupSlotData *slot);
 static int32 groupIncMemUsage(ResGroupData *group,
 							  ResGroupSlotData *slot,
 							  int32 chunks);
-static void groupDecMemUsage(ResGroupData *group,
-							 ResGroupSlotData *slot,
-							 int32 chunks);
+static int32 groupDecMemUsage(ResGroupData *group,
+							  ResGroupSlotData *slot,
+							  int32 chunks);
 static void initSlot(ResGroupSlotData *slot, ResGroupData *group,
 					 int32 slotMemQuota);
 static void selfAttachResGroup(ResGroupData *group, ResGroupSlotData *slot);
@@ -954,24 +956,27 @@ ResGroupReserveMemory(int32 memoryChunks, int32 overuseChunks, bool *waiverUsed)
 	overuseMem = groupIncMemUsage(group, slot, memoryChunks);
 
 	/* then check whether there is over usage */
-	if (CritSectionCount == 0 && overuseMem > overuseChunks)
+	if (CritSectionCount == 0)
 	{
-		/* if the over usage is larger than allowed then revert the change */
-		groupDecMemUsage(group, slot, memoryChunks);
+		if (overuseMem > overuseChunks)
+		{
+			/* if the over usage is larger than allowed then revert the change */
+			groupDecMemUsage(group, slot, memoryChunks);
 
-		/* also revert in proc */
-		self->memUsage -= memoryChunks;
-		Assert(self->memUsage >= 0);
+			/* also revert in proc */
+			self->memUsage -= memoryChunks;
+			Assert(self->memUsage >= 0);
 
-		if (overuseChunks == 0)
-			ResGroupDumpMemoryInfo();
+			if (overuseChunks == 0)
+				ResGroupDumpMemoryInfo();
 
-		return false;
-	}
-	else if (CritSectionCount == 0 && overuseMem > 0)
-	{
-		/* the over usage is within the allowed threshold */
-		*waiverUsed = true;
+			return false;
+		}
+		else if (overuseMem > 0)
+		{
+			/* the over usage is within the allowed threshold */
+			*waiverUsed = true;
+		}
 	}
 
 	return true;
@@ -1106,14 +1111,15 @@ bindGroupOperation(ResGroupData *group)
 /*
  * Add chunks into group and slot memory usage.
  *
- * Return the over used chunks.
+ * Return the total over used chunks of global share
  */
 static int32
 groupIncMemUsage(ResGroupData *group, ResGroupSlotData *slot, int32 chunks)
 {
-	int32			slotMemUsage;
-	int32			sharedMemUsage;
-	int32			overuseMem = 0;
+	int32			slotMemUsage;	/* the memory current slot has been used */
+	int32			sharedMemUsage;	/* the total shared memory usage,
+										sum of group share and global share */
+	int32			globalOveruse = 0;	/* the total over used chunks of global share*/
 
 	/* Add the chunks to memUsage in slot */
 	slotMemUsage = pg_atomic_add_fetch_u32((pg_atomic_uint32 *) &slot->memUsage,
@@ -1123,30 +1129,40 @@ groupIncMemUsage(ResGroupData *group, ResGroupSlotData *slot, int32 chunks)
 	sharedMemUsage = slotMemUsage - slot->memQuota;
 	if (sharedMemUsage > 0)
 	{
-		int32			total;
-
 		/* Decide how many chunks should be counted as shared memory */
-		sharedMemUsage = Min(sharedMemUsage, chunks);
-
-		/* Add these chunks to memSharedUsage in group */
-		total = pg_atomic_add_fetch_u32((pg_atomic_uint32 *) &group->memSharedUsage,
-										sharedMemUsage);
-
-		/* Calculate the over used chunks */
-		overuseMem = Max(0, total - group->memSharedGranted);
+		int32 deltaSharedMemUsage = Min(sharedMemUsage, chunks);
+
+		/* Add these chunks to memSharedUsage in group, 
+		 * and record the old value*/
+		int32 oldSharedUsage = pg_atomic_fetch_add_u32((pg_atomic_uint32 *)
+													   &group->memSharedUsage,
+													   deltaSharedMemUsage);
+		/* the free space of group share */
+		int32 oldSharedFree = Max(0, group->memSharedGranted - oldSharedUsage);
+
+		/* Calculate the global over used chunks */
+		int32 deltaGlobalSharedMemUsage = Max(0, deltaSharedMemUsage - oldSharedFree);
+
+		/* freeChunks -= deltaGlobalSharedMemUsage and get the new value */
+		int32 newFreeChunks = pg_atomic_sub_fetch_u32((pg_atomic_uint32 *)
+													  &pResGroupControl->freeChunks,
+													  deltaGlobalSharedMemUsage);
+		/* calculate the total over used chunks of global share */
+		globalOveruse = Max(0, 0 - newFreeChunks);
 	}
 
 	/* Add the chunks to memUsage in group */
 	pg_atomic_add_fetch_u32((pg_atomic_uint32 *) &group->memUsage,
 							chunks);
 
-	return overuseMem;
+	return globalOveruse;
 }
 
 /*
- * Sub chunks from group and slot memory usage.
+ * Sub chunks from group ,slot memory usage and global shared memory.
+ * return memory chunks of global shared released this time
  */
-static void
+static int32 
 groupDecMemUsage(ResGroupData *group, ResGroupSlotData *slot, int32 chunks)
 {
 	int32			value;
@@ -1168,13 +1184,25 @@ groupDecMemUsage(ResGroupData *group, ResGroupSlotData *slot, int32 chunks)
 	if (sharedMemUsage > 0)
 	{
 		/* Decide how many chunks should be counted as shared memory */
-		sharedMemUsage = Min(sharedMemUsage, chunks);
+		int32 deltaSharedMemUsage = Min(sharedMemUsage, chunks);
 
 		/* Sub chunks from memSharedUsage in group */
-		value = pg_atomic_sub_fetch_u32((pg_atomic_uint32 *) &group->memSharedUsage,
-										sharedMemUsage);
-		Assert(value >= 0);
+		int32 oldSharedUsage = pg_atomic_fetch_sub_u32((pg_atomic_uint32 *) &group->memSharedUsage,
+										deltaSharedMemUsage);
+		Assert(oldSharedUsage >= deltaSharedMemUsage);
+
+		/* record the total global share usage of current group */
+		int32 grpTotalGlobalUsage = Max(0, oldSharedUsage - group->memSharedGranted);
+		/* calculate the global share usage of current release */
+		int32 deltaGlobalSharedMemUsage = Min(grpTotalGlobalUsage, deltaSharedMemUsage);
+		/* add chunks to global shared memory */
+		pg_atomic_add_fetch_u32((pg_atomic_uint32 *)
+								&pResGroupControl->freeChunks,
+								deltaGlobalSharedMemUsage);
+		return deltaGlobalSharedMemUsage;
 	}
+
+	return 0;
 }
 
 /*
@@ -1593,18 +1621,34 @@ groupApplyMemCaps(ResGroupData *group)
 static int32
 mempoolReserve(Oid groupId, int32 chunks)
 {
+	int32 oldFreeChunks;
+	int32 newFreeChunks;
+	int32 reserved = 0;
+
 	Assert(LWLockHeldExclusiveByMe(ResGroupLock));
 
-	LOG_RESGROUP_DEBUG(LOG, "allocate %u out of %u chunks to group %d",
-					   chunks, pResGroupControl->freeChunks, groupId);
+	/* Compare And Save to avoid concurrency problem without using lock */
+	while (true)
+	{
+		oldFreeChunks = pg_atomic_read_u32((pg_atomic_uint32 *)
+										   &pResGroupControl->freeChunks);
+		reserved = Min(Max(0, oldFreeChunks), chunks);
+		newFreeChunks = oldFreeChunks - reserved;
+		if (reserved == 0)
+			break;
+		if (pg_atomic_compare_exchange_u32((pg_atomic_uint32 *)
+										   &pResGroupControl->freeChunks,
+										   (uint32 *) &oldFreeChunks,
+										   (uint32) newFreeChunks))
+			break;
+	}
 
-	chunks = Min(pResGroupControl->freeChunks, chunks);
-	pResGroupControl->freeChunks -= chunks;
+	LOG_RESGROUP_DEBUG(LOG, "allocate %u out of %u chunks to group %d",
+					   reserved, oldFreeChunks, groupId);
 
-	Assert(pResGroupControl->freeChunks >= 0);
-	Assert(pResGroupControl->freeChunks <= pResGroupControl->totalChunks);
+	Assert(newFreeChunks <= pResGroupControl->totalChunks);
 
-	return chunks;
+	return reserved;
 }
 
 /*
@@ -1613,16 +1657,19 @@ mempoolReserve(Oid groupId, int32 chunks)
 static void
 mempoolRelease(Oid groupId, int32 chunks)
 {
-	LOG_RESGROUP_DEBUG(LOG, "free %u to pool(%u) chunks from group %d",
-					   chunks, pResGroupControl->freeChunks, groupId);
+	int32 newFreeChunks;
 
 	Assert(LWLockHeldExclusiveByMe(ResGroupLock));
 	Assert(chunks >= 0);
 
-	pResGroupControl->freeChunks += chunks;
+	newFreeChunks = pg_atomic_add_fetch_u32((pg_atomic_uint32 *)
+											&pResGroupControl->freeChunks,
+											chunks);
+
+	LOG_RESGROUP_DEBUG(LOG, "free %u to pool(%u) chunks from group %d",
+					   chunks, newFreeChunks - chunks, groupId);
 
-	Assert(pResGroupControl->freeChunks >= 0);
-	Assert(pResGroupControl->freeChunks <= pResGroupControl->totalChunks);
+	Assert(newFreeChunks <= pResGroupControl->totalChunks);
 }
 
 /*
diff --git a/src/test/isolation2/expected/resgroup/resgroup_alter_memory_spill_ratio.out b/src/test/isolation2/expected/resgroup/resgroup_alter_memory_spill_ratio.out
index 29d413094a5738b57a91c316f6599ea069912675..86b5c3943d7fccbcfc5c9ffbf009b46fbe396272 100644
--- a/src/test/isolation2/expected/resgroup/resgroup_alter_memory_spill_ratio.out
+++ b/src/test/isolation2/expected/resgroup/resgroup_alter_memory_spill_ratio.out
@@ -25,7 +25,7 @@ groupname    |memory_shared_quota|proposed_memory_shared_quota|memory_spill_rati
 rg_spill_test|20                 |20                          |20                |20                         
 (1 row)
 
--- positive, memory_spill_ratio range is [0, 100]
+-- positive, memory_spill_ratio range is [0, 2147483647]
 ALTER RESOURCE GROUP rg_spill_test SET MEMORY_SPILL_RATIO 0;
 ALTER
 SELECT * FROM rg_spill_status;
@@ -58,9 +58,9 @@ groupname    |memory_shared_quota|proposed_memory_shared_quota|memory_spill_rati
 rg_spill_test|20                 |20                          |81                |81                         
 (1 row)
 
--- negative: memory_spill_ratio is larger than RESGROUP_MAX_MEMORY_SPILL_RATIO
-ALTER RESOURCE GROUP rg_spill_test SET MEMORY_SPILL_RATIO 101;
-ERROR:  memory_spill_ratio range is [0, 100]
+-- negative: memory_spill_ratio is negative
+ALTER RESOURCE GROUP rg_spill_test SET MEMORY_SPILL_RATIO -1;
+ERROR:  memory_spill_ratio range is [0, 2147483647]
 SELECT * FROM rg_spill_status;
 groupname    |memory_shared_quota|proposed_memory_shared_quota|memory_spill_ratio|proposed_memory_spill_ratio
 -------------+-------------------+----------------------------+------------------+---------------------------
diff --git a/src/test/isolation2/expected/resgroup/resgroup_set_memory_spill_ratio.out b/src/test/isolation2/expected/resgroup/resgroup_set_memory_spill_ratio.out
index c22bfe742c1dd2f60b8bcaddc993ec59eaa4ef2a..800494a1c1a36c711451a46dad45ee2dc6f289d4 100644
--- a/src/test/isolation2/expected/resgroup/resgroup_set_memory_spill_ratio.out
+++ b/src/test/isolation2/expected/resgroup/resgroup_set_memory_spill_ratio.out
@@ -63,8 +63,8 @@ SELECT 1;
 (1 row)
 
 -- negative set to session level
-SET MEMORY_SPILL_RATIO TO 101;
-ERROR:  101 is outside the valid range for parameter "memory_spill_ratio" (0 .. 100)
+SET MEMORY_SPILL_RATIO TO -1;
+ERROR:  -1 is outside the valid range for parameter "memory_spill_ratio" (0 .. 2147483647)
 SHOW MEMORY_SPILL_RATIO;
 memory_spill_ratio
 ------------------
diff --git a/src/test/isolation2/expected/resgroup/resgroup_syntax.out b/src/test/isolation2/expected/resgroup/resgroup_syntax.out
index d93efbb357ccedb27ebe7e3e768d6e4ac7164140..26f934eee4a66bdb6e4aaf2d8f18a0b8d6b3b7c9 100644
--- a/src/test/isolation2/expected/resgroup/resgroup_syntax.out
+++ b/src/test/isolation2/expected/resgroup/resgroup_syntax.out
@@ -176,7 +176,7 @@ ERROR:  memory_auditor should be "vmtracker" or "cgroup"
 CREATE RESOURCE GROUP rg_test_group WITH (concurrency=1, cpu_rate_limit=10, memory_limit=10, memory_auditor="cgroup");
 ERROR:  resource group concurrency must be 0 when group memory_auditor is cgroup
 
--- memory_spill_ratio range is [0, 100]
+-- memory_spill_ratio range is [0, 2147483647]
 -- no limit on the sum of memory_shared_quota and memory_spill_ratio
 CREATE RESOURCE GROUP rg_test_group WITH (cpu_rate_limit=10, memory_limit=10, memory_shared_quota=10, memory_spill_ratio=0);
 CREATE
@@ -187,7 +187,7 @@ CREATE
 DROP RESOURCE GROUP rg_test_group;
 DROP
 CREATE RESOURCE GROUP rg_test_group WITH (cpu_rate_limit=10, memory_limit=10, memory_shared_quota=10, memory_spill_ratio=-1);
-ERROR:  memory_spill_ratio range is [0, 100]
+ERROR:  memory_spill_ratio range is [0, 2147483647]
 CREATE RESOURCE GROUP rg_test_group WITH (cpu_rate_limit=10, memory_limit=10, memory_shared_quota=-1, memory_spill_ratio=10);
 ERROR:  memory_shared_quota range is [0, 100]
 
@@ -251,7 +251,7 @@ CREATE
 DROP RESOURCE GROUP rg_test_group;
 DROP
 
--- memory_spill_ratio range is [0, 100]
+-- memory_spill_ratio range is [0, 2147483647]
 -- no limit on the sum of memory_shared_quota and memory_spill_ratio
 CREATE RESOURCE GROUP rg_test_group WITH (cpu_rate_limit=10, memory_limit=10, memory_shared_quota=0, memory_spill_ratio=1);
 CREATE
diff --git a/src/test/isolation2/expected/resgroup/resgroup_unlimit_memory_spill_ratio.out b/src/test/isolation2/expected/resgroup/resgroup_unlimit_memory_spill_ratio.out
index be374cf5fd7037d88a154084ad4363494d76619d..5b1332d8acc49833dfd6850f385d1cf1b9b99b6a 100644
--- a/src/test/isolation2/expected/resgroup/resgroup_unlimit_memory_spill_ratio.out
+++ b/src/test/isolation2/expected/resgroup/resgroup_unlimit_memory_spill_ratio.out
@@ -20,12 +20,7 @@ DROP RESOURCE GROUP rg_spill_test;
 DROP
 
 CREATE RESOURCE GROUP rg_spill_test WITH (concurrency=10, cpu_rate_limit=20, memory_limit=20, memory_shared_quota=50, memory_spill_ratio=-1);
-ERROR:  memory_spill_ratio range is [0, 100]
-DROP RESOURCE GROUP rg_spill_test;
-ERROR:  resource group "rg_spill_test" does not exist
-
-CREATE RESOURCE GROUP rg_spill_test WITH (concurrency=10, cpu_rate_limit=20, memory_limit=20, memory_shared_quota=50, memory_spill_ratio=101);
-ERROR:  memory_spill_ratio range is [0, 100]
+ERROR:  memory_spill_ratio range is [0, 2147483647]
 DROP RESOURCE GROUP rg_spill_test;
 ERROR:  resource group "rg_spill_test" does not exist
 
@@ -40,9 +35,9 @@ ALTER
 ALTER RESOURCE GROUP rg_spill_test SET MEMORY_SPILL_RATIO 100;
 ALTER
 ALTER RESOURCE GROUP rg_spill_test SET MEMORY_SPILL_RATIO -1;
-ERROR:  memory_spill_ratio range is [0, 100]
-ALTER RESOURCE GROUP rg_spill_test SET MEMORY_SPILL_RATIO 101;
-ERROR:  memory_spill_ratio range is [0, 100]
+ERROR:  memory_spill_ratio range is [0, 2147483647]
+ALTER RESOURCE GROUP rg_spill_test SET MEMORY_SPILL_RATIO 10000;
+ALTER
 
 DROP RESOURCE GROUP rg_spill_test;
 DROP
@@ -91,7 +86,7 @@ SELECT 1;
 (1 row)
 
 SET MEMORY_SPILL_RATIO TO -1;
-ERROR:  -1 is outside the valid range for parameter "memory_spill_ratio" (0 .. 100)
+ERROR:  -1 is outside the valid range for parameter "memory_spill_ratio" (0 .. 2147483647)
 SHOW MEMORY_SPILL_RATIO;
 memory_spill_ratio
 ------------------
@@ -103,12 +98,12 @@ SELECT 1;
 1       
 (1 row)
 
-SET MEMORY_SPILL_RATIO TO 101;
-ERROR:  101 is outside the valid range for parameter "memory_spill_ratio" (0 .. 100)
+SET MEMORY_SPILL_RATIO TO 10000;
+SET
 SHOW MEMORY_SPILL_RATIO;
 memory_spill_ratio
 ------------------
-100               
+10000             
 (1 row)
 SELECT 1;
 ?column?
diff --git a/src/test/isolation2/input/resgroup/resgroup_memory_limit.source b/src/test/isolation2/input/resgroup/resgroup_memory_limit.source
index 0b6d1d99a401d0431603b26e1640f74d92bade55..23cf4625227d015e949db62da965c3cba3d5fe28 100644
--- a/src/test/isolation2/input/resgroup/resgroup_memory_limit.source
+++ b/src/test/isolation2/input/resgroup/resgroup_memory_limit.source
@@ -1,180 +1,506 @@
 -- start_ignore
 DROP ROLE IF EXISTS role1_memory_test;
 DROP RESOURCE GROUP rg1_memory_test;
+DROP RESOURCE GROUP rg2_memory_test;
 -- end_ignore
 
 CREATE OR REPLACE FUNCTION resGroupPalloc(float) RETURNS int AS
 '@abs_builddir@/../regress/regress@DLSUFFIX@', 'resGroupPalloc'
 LANGUAGE C READS SQL DATA;
 
-CREATE OR REPLACE FUNCTION hold_memory_by_percent(int, float) RETURNS int AS $$
-    SELECT * FROM resGroupPalloc($2)
+CREATE OR REPLACE FUNCTION hold_memory_by_percent(float) RETURNS int AS $$
+	SELECT * FROM resGroupPalloc($1)
 $$ LANGUAGE sql;
 
---
--- first create the resgroup with memory_shared_quota == 0.
--- so each resgroup slot gets a fixed memory quota of 0.5.
---
-
+CREATE OR REPLACE VIEW rg_mem_status AS
+	SELECT groupname, memory_limit, proposed_memory_limit,
+		   memory_shared_quota, proposed_memory_shared_quota
+	FROM gp_toolkit.gp_resgroup_config
+	WHERE groupname='rg1_memory_test' OR groupname='rg2_memory_test'
+	ORDER BY groupid;
+
+CREATE OR REPLACE VIEW memory_result AS SELECT rsgname, memory_usage from gp_toolkit.gp_resgroup_status;
+
+--	1) single allocation
+--	Group Share Quota = 0
+--	Global Share Quota > 0
+--	Slot Quota > 0
+--	-----------------------
+
+--	we assume system total chunks is 100%
+--	rg1's expected: 100% * 52% => 52%
+--	rg1's slot quota: 52% / 2 * 2 => 52%
+--	rg1's single slot quota: 52% / 2 => 26%
+--	rg1's shared quota: %52 - %52 => %0
+--	system free chunks: 100% - 10% - 30% - 52% => 8%
+--	memory available to one slot in rg1: 52%/2 + 0% + 8% => 34%
 CREATE RESOURCE GROUP rg1_memory_test
     WITH (concurrency=2, cpu_rate_limit=10,
-          memory_limit=50, memory_shared_quota=0);
+          memory_limit=52, memory_shared_quota=0);
 CREATE ROLE role1_memory_test RESOURCE GROUP rg1_memory_test;
 
--- 1) on QD only with memory_shared_quota == 0
-
+--	1a) on QD
 1: SET ROLE TO role1_memory_test;
-1: SELECT hold_memory_by_percent(1,0.2);
-1: SELECT hold_memory_by_percent(1,0.2);
-1: SELECT hold_memory_by_percent(1,0.2);
+1: SELECT hold_memory_by_percent(0.14 / 0.52);
+1: SELECT hold_memory_by_percent(0.14 / 0.52);
+1: SELECT hold_memory_by_percent(0.14 / 0.52);
 1q:
 
 1: SET ROLE TO role1_memory_test;
 1: BEGIN;
-1: SELECT hold_memory_by_percent(1,0.2);
-1: SELECT hold_memory_by_percent(1,0.2);
-1: SELECT hold_memory_by_percent(1,0.2);
+1: SELECT hold_memory_by_percent(0.14 / 0.52);
+1: SELECT hold_memory_by_percent(0.14 / 0.52);
+1: SELECT hold_memory_by_percent(0.14 / 0.52);
 1q:
 
 1: SET ROLE TO role1_memory_test;
-1: SELECT hold_memory_by_percent(1,0.45);
-1: SELECT hold_memory_by_percent(1,0.45);
+1: SELECT hold_memory_by_percent(0.42 / 0.52);
 1q:
 
+--	1b) on QEs
 1: SET ROLE TO role1_memory_test;
-1: BEGIN;
-1: SELECT hold_memory_by_percent(1,0.45);
-1: SELECT hold_memory_by_percent(1,0.45);
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.14 / 0.52)=0;
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.14 / 0.52)=0;
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.14 / 0.52)=0;
 1q:
 
 1: SET ROLE TO role1_memory_test;
-1: SELECT hold_memory_by_percent(1,0.55);
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.42 / 0.52)=0;
 1q:
 
--- 2) on QEs with memory_shared_quota == 0
+DROP ROLE role1_memory_test;
+DROP RESOURCE GROUP rg1_memory_test;
+
+--	2) single allocation
+--	Group Share Quota > 0
+--	Global Share Quota > 0
+--	Slot Quota > 0
+--	-----------------------
+
+--	we assume system total chunks is 100%
+--	rg1's expected: 100% * 52 / 100 => 52%
+--	rg1's slot quota: 52% * 60 /100 => 31%
+--	rg1's single slot quota: 31% / 2 => 15.5%
+--	rg1's shared quota: 52% - 31% => 21%
+--	system free chunks: 100% - 10% - 30% - 52% => 8%
+--	memory available to one slot in rg1: 15.5% + 21% + 8% => 44.5%
+
+CREATE RESOURCE GROUP rg1_memory_test
+    WITH (concurrency=2, cpu_rate_limit=10,
+          memory_limit=52, memory_shared_quota=40);
+CREATE ROLE role1_memory_test RESOURCE GROUP rg1_memory_test;
+
+--	2a) on QD
+1: SET ROLE TO role1_memory_test;
+1: SELECT hold_memory_by_percent(0.12 / 0.52);
+1: SELECT hold_memory_by_percent(0.12 / 0.52);
+1: SELECT hold_memory_by_percent(0.12 / 0.52);
+1: SELECT hold_memory_by_percent(0.12 / 0.52);
+1q:
 
 1: SET ROLE TO role1_memory_test;
-1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.2)=0;
-1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.2)=0;
-1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.2)=0;
+1: BEGIN;
+1: SELECT hold_memory_by_percent(0.12 / 0.52);
+1: SELECT hold_memory_by_percent(0.12 / 0.52);
+1: SELECT hold_memory_by_percent(0.12 / 0.52);
+1: SELECT hold_memory_by_percent(0.12 / 0.52);
 1q:
 
 1: SET ROLE TO role1_memory_test;
-1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.45)=0;
+1: SELECT hold_memory_by_percent(0.48 / 0.52);
 1q:
 
+--	2b) on QEs
 1: SET ROLE TO role1_memory_test;
-1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.55)=0;
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.12 / 0.52)=0;
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.12 / 0.52)=0;
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.12 / 0.52)=0;
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.12 / 0.52)=0;
 1q:
 
---
--- now recreate the resgroup with memory_shared_quota > 0.
--- so each resgroup slot gets a fixed memory quota of 0.3,
--- there is also a shared memory pool of 0.4, so the actual
--- memory usage in each slot can be 0.3~0.7.
---
+1: SET ROLE TO role1_memory_test;
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.48 / 0.52)=0;
+1q:
 
 DROP ROLE role1_memory_test;
 DROP RESOURCE GROUP rg1_memory_test;
+
+--	3) single allocation
+--	Group Share Quota > 0
+--	Global Share Quota > 0
+--	Slot Quota = 0
+--	-----------------------
+
+--	we assume system total chunks is 100%
+--	rg1's expected: 100% * 52 / 100 => 52%
+--	rg1's slot quota: 0
+--	rg1's shared quota: 52%
+--	system free chunks: 100% - 10% - 30% - 52% => 8%
+--	memory available to one slot in rg1: 52% + 8% => 60%
+
 CREATE RESOURCE GROUP rg1_memory_test
     WITH (concurrency=2, cpu_rate_limit=10,
-          memory_limit=10, memory_shared_quota=40);
+          memory_limit=52, memory_shared_quota=100);
 CREATE ROLE role1_memory_test RESOURCE GROUP rg1_memory_test;
 
--- 3) on QD with memory_shared_quota > 0
-
+--	3a) on QD
 1: SET ROLE TO role1_memory_test;
-1: SELECT hold_memory_by_percent(1,0.65);
+1: SELECT hold_memory_by_percent(0.25 / 0.52);
+1: SELECT hold_memory_by_percent(0.25 / 0.52);
+1: SELECT hold_memory_by_percent(0.25 / 0.52);
 1q:
 
 1: SET ROLE TO role1_memory_test;
-1: SELECT hold_memory_by_percent(1,0.75);
+1: BEGIN;
+1: SELECT hold_memory_by_percent(0.25 / 0.52);
+1: SELECT hold_memory_by_percent(0.25 / 0.52);
+1: SELECT hold_memory_by_percent(0.25 / 0.52);
 1q:
 
 1: SET ROLE TO role1_memory_test;
-1: SELECT hold_memory_by_percent(1,0.2);
-1: SELECT hold_memory_by_percent(1,0.2);
-1: SELECT hold_memory_by_percent(1,0.2);
-1: SELECT hold_memory_by_percent(1,0.2);
+1: SELECT hold_memory_by_percent(0.75 / 0.52);
 1q:
 
--- 4) on QEs with memory_shared_quota > 0
+--	3b) on QEs
+1: SET ROLE TO role1_memory_test;
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.25 / 0.52)=0;
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.25 / 0.52)=0;
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.25 / 0.52)=0;
+1q:
 
 1: SET ROLE TO role1_memory_test;
-1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.2)=0;
-1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.2)=0;
-1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.2)=0;
-1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.2)=0;
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.75 / 0.52)=0;
 1q:
 
--- 5) QD: concurrent transactions in same group with memory_shared_quota > 0
+DROP ROLE role1_memory_test;
+DROP RESOURCE GROUP rg1_memory_test;
+
+--	4) multi allocation in one group
+--	Group Share Quota = 0
+--	Global Share Quota > 0
+--	Slot Quota > 0
+--	-----------------------
+
+--	we assume system total chunks is 100%
+--	rg1's expected: 100% * 52 / 100 => 52%
+--	rg1's slot quota: 52% / 2 * 2 => 52%
+--	rg1's single slot quota: 52% / 2 => 26%
+--	rg1's shared quota: 0
+--	system free chunks: 100% - 10% - 30% - 52% => 8%
+--	memory available to one slot in rg1: 26% + 8% => 34%
+
+CREATE RESOURCE GROUP rg1_memory_test
+    WITH (concurrency=2, cpu_rate_limit=10,
+          memory_limit=52, memory_shared_quota=0);
+CREATE ROLE role1_memory_test RESOURCE GROUP rg1_memory_test;
 
+--	4a) on QD
+--	not exceed the global share
 1: SET ROLE TO role1_memory_test;
-1: BEGIN;
-1: SELECT hold_memory_by_percent(1,0.6);
 2: SET ROLE TO role1_memory_test;
+1: BEGIN;
 2: BEGIN;
-2: SELECT hold_memory_by_percent(1,0.3);
+1: SELECT hold_memory_by_percent(0.28 / 0.52);
+2: SELECT hold_memory_by_percent(0.28 / 0.52);
+1q:
 2q:
+
+--	exceed the global share
+1: SET ROLE TO role1_memory_test;
 2: SET ROLE TO role1_memory_test;
+1: BEGIN;
 2: BEGIN;
-2: SELECT hold_memory_by_percent(1,0.3);
-2: SELECT hold_memory_by_percent(1,0.2);
-2q:
+1: SELECT hold_memory_by_percent(0.32 / 0.52);
+2: SELECT hold_memory_by_percent(0.32 / 0.52);
 1q:
+2q:
 
--- 6) QE: concurrent transactions in same group with memory_shared_quota > 0
+--	allocate serially
+1: SET ROLE TO role1_memory_test;
+2: SET ROLE TO role1_memory_test;
+1: BEGIN;
+2: BEGIN;
+1: SELECT hold_memory_by_percent(0.32 / 0.52);
+1q:
+SELECT pg_sleep(1);
+2: SELECT hold_memory_by_percent(0.32 / 0.52);
+2q:
 
+--	4b) on QEs
+--	not exceed the global share
 1: SET ROLE TO role1_memory_test;
+2: SET ROLE TO role1_memory_test;
 1: BEGIN;
-1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.6)=0;
+2: BEGIN;
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.28 / 0.52)=0;
+2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.28 / 0.52)=0;
+1q:
+2q:
+
+--	exceed the global share
+1: SET ROLE TO role1_memory_test;
 2: SET ROLE TO role1_memory_test;
+1: BEGIN;
 2: BEGIN;
-2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.3)=0;
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.32 / 0.52)=0;
+2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.32 / 0.52)=0;
+1q:
 2q:
+
+--	allocate serially
+1: SET ROLE TO role1_memory_test;
 2: SET ROLE TO role1_memory_test;
+1: BEGIN;
 2: BEGIN;
-2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.3)=0;
-2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.2)=0;
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.32 / 0.52)=0;
+1q:
+SELECT pg_sleep(1);
+2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.32 / 0.52)=0;
 2q:
+
+DROP ROLE role1_memory_test;
+DROP RESOURCE GROUP rg1_memory_test;
+
+--	5) multi allocation in one group
+--	Group Share Quota > 0
+--	Global Share Quota > 0
+--	Slot Quota > 0
+--	-----------------------
+
+--	we assume system total chunks is 100%
+--	rg1's expected: 100% * 52 / 100 => 52%
+--	rg1's slot quota: 52% * 50 / 100 => 26%
+--	rg1's single slot quota: 26% / 2 => 13%
+--	rg1's shared quota: 52% - 13% * 2 => 26%
+--	system free chunks: 100% - 10% - 30% - 52% => 8%
+--	memory available to one slot in rg1: 13% + 26% + 8% => 47%
+
+CREATE RESOURCE GROUP rg1_memory_test
+    WITH (concurrency=2, cpu_rate_limit=10,
+          memory_limit=52, memory_shared_quota=50);
+CREATE ROLE role1_memory_test RESOURCE GROUP rg1_memory_test;
+
+--	5a) on QD
+--	not exceed the global share
+1: SET ROLE TO role1_memory_test;
+2: SET ROLE TO role1_memory_test;
+1: BEGIN;
+2: BEGIN;
+-- reserve all the group shared quota
+1: SELECT hold_memory_by_percent(0.39 / 0.52);
+-- must allocate from global share
+2: SELECT hold_memory_by_percent(0.2 / 0.52);
 1q:
+2q:
 
--- 7) QD: concurrent transactions in same group with memory_shared_quota = 100
+--	exceed the global share
+1: SET ROLE TO role1_memory_test;
+2: SET ROLE TO role1_memory_test;
+1: BEGIN;
+2: BEGIN;
+1: SELECT hold_memory_by_percent(0.39 / 0.52);
+2: SELECT hold_memory_by_percent(0.39 / 0.52);
+1q:
+2q:
 
-ALTER RESOURCE GROUP rg1_memory_test SET memory_shared_quota 100;
+--	allocate serially
+1: SET ROLE TO role1_memory_test;
+2: SET ROLE TO role1_memory_test;
+1: BEGIN;
+2: BEGIN;
+1: SELECT hold_memory_by_percent(0.39 / 0.52);
+1q:
+SELECT pg_sleep(1);
+2: SELECT hold_memory_by_percent(0.39 / 0.52);
+2q:
 
+--	5b) on QEs
+--	not exceed the global share
 1: SET ROLE TO role1_memory_test;
+2: SET ROLE TO role1_memory_test;
 1: BEGIN;
-1: SELECT hold_memory_by_percent(1,0.6);
+2: BEGIN;
+-- reserve all the group shared quota
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.39 / 0.52)=0;
+-- must allocate from global share
+2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.2 / 0.52)=0;
+1q:
+2q:
+
+--	exceed the global share
+1: SET ROLE TO role1_memory_test;
 2: SET ROLE TO role1_memory_test;
+1: BEGIN;
 2: BEGIN;
-2: SELECT hold_memory_by_percent(1,0.3);
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.39 / 0.52)=0;
+2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.39 / 0.52)=0;
+1q:
 2q:
+
+--	allocate serially
+1: SET ROLE TO role1_memory_test;
 2: SET ROLE TO role1_memory_test;
+1: BEGIN;
 2: BEGIN;
-2: SELECT hold_memory_by_percent(1,0.3);
-2: SELECT hold_memory_by_percent(1,0.2);
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.39 / 0.52)=0;
+1q:
+SELECT pg_sleep(1);
+2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.39 / 0.52)=0;
 2q:
+
+DROP ROLE role1_memory_test;
+DROP RESOURCE GROUP rg1_memory_test;
+
+--	6) multi allocation in different group
+--	Group Share Quota > 0
+--	Global Share Quota > 0
+--	Slot Quota > 0
+--	-----------------------
+
+--	we assume system total chunks is 100%
+--	rg1's expected: 100% * 20 / 100 => 20%
+--	rg1's slot quota: 20% * 60 / 100 / 2 * 2 => 12%
+--	rg1's single slot quota: 12% / 2 => 6%
+--	rg1's shared quota: 20% - 6% * 2 => 8%
+--	rg2 same as rg1
+--	system free chunks: 100% - 10% - 30% - 100%*20/100 - 100%*20/100 => 20%
+--	memory available to one slot in rg1/rg2: 6% + 8% + 20% => 34%
+
+CREATE RESOURCE GROUP rg1_memory_test
+    WITH (concurrency=2, cpu_rate_limit=10,
+          memory_limit=20, memory_shared_quota=40);
+CREATE RESOURCE GROUP rg2_memory_test
+    WITH (concurrency=2, cpu_rate_limit=10,
+          memory_limit=20, memory_shared_quota=40);
+CREATE ROLE role1_memory_test RESOURCE GROUP rg1_memory_test;
+CREATE ROLE role2_memory_test RESOURCE GROUP rg2_memory_test;
+
+--	6a) on QD
+--	not exceed the global share
+1: SET ROLE TO role1_memory_test;
+2: SET ROLE TO role2_memory_test;
+1: BEGIN;
+2: BEGIN;
+1: SELECT hold_memory_by_percent(0.2 / 0.2);
+2: SELECT hold_memory_by_percent(0.2 / 0.2);
 1q:
+2q:
 
--- 8) QE: concurrent transactions in same group with memory_shared_quota = 100
+--	exceed the global share
+1: SET ROLE TO role1_memory_test;
+2: SET ROLE TO role2_memory_test;
+1: BEGIN;
+2: BEGIN;
+1: SELECT hold_memory_by_percent(0.3 / 0.2);
+2: SELECT hold_memory_by_percent(0.3 / 0.2);
+1q:
+2q:
 
-ALTER RESOURCE GROUP rg1_memory_test SET memory_shared_quota 100;
+--	allocate serially
+1: SET ROLE TO role1_memory_test;
+2: SET ROLE TO role2_memory_test;
+1: BEGIN;
+2: BEGIN;
+1: SELECT hold_memory_by_percent(0.3 / 0.2);
+1q:
+SELECT pg_sleep(1);
+2: SELECT hold_memory_by_percent(0.3 / 0.2);
+2q:
 
+--	6b) on QEs
+--	not exceed the global share
 1: SET ROLE TO role1_memory_test;
+2: SET ROLE TO role2_memory_test;
 1: BEGIN;
-1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.6)=0;
-2: SET ROLE TO role1_memory_test;
 2: BEGIN;
-2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.3)=0;
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.2 / 0.2)=0;
+2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.2 / 0.2)=0;
+1q:
 2q:
-2: SET ROLE TO role1_memory_test;
+
+--	exceed the global share
+1: SET ROLE TO role1_memory_test;
+2: SET ROLE TO role2_memory_test;
+1: BEGIN;
 2: BEGIN;
-2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.3)=0;
-2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.2)=0;
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.3 / 0.2)=0;
+2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.3 / 0.2)=0;
+1q:
 2q:
+
+--	allocate serially
+1: SET ROLE TO role1_memory_test;
+2: SET ROLE TO role2_memory_test;
+1: BEGIN;
+2: BEGIN;
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.3 / 0.2)=0;
 1q:
+SELECT pg_sleep(1);
+2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.3 / 0.2)=0;
+2q:
 
--- cleanup
 DROP ROLE role1_memory_test;
+DROP ROLE role2_memory_test;
 DROP RESOURCE GROUP rg1_memory_test;
+DROP RESOURCE GROUP rg2_memory_test;
+
+--	7) DBA can increase global shared memory by decreasing 
+--		any existing group_memory_limit
+--	-----------------------
+
+--	we assume system total chunks is 100%
+--	rg1's expected: 100% * 30 / 100 => 30%
+--	rg1's slot quota: 30%
+--	rg1's single slot quota: 30% / 2 => 15%
+--	rg1's shared quota: 0
+--	rg2 same as rg1
+--	system free chunks: 100% - 10% - 30% - 30% - 30% => 0
+--	memory available to one slot in rg1/rg2: 15% + 0 + 0 => 15%
+
+CREATE RESOURCE GROUP rg1_memory_test
+    WITH (concurrency=2, cpu_rate_limit=10,
+          memory_limit=30, memory_shared_quota=0);
+CREATE RESOURCE GROUP rg2_memory_test
+    WITH (concurrency=2, cpu_rate_limit=10,
+          memory_limit=30, memory_shared_quota=0);
+CREATE ROLE role1_memory_test RESOURCE GROUP rg1_memory_test;
+CREATE ROLE role2_memory_test RESOURCE GROUP rg2_memory_test;
+
+--	7a) on QD
+--	not enough memory
+1: SET ROLE TO role1_memory_test;
+1: SELECT hold_memory_by_percent(0.2 / 0.3);
+1q:
+
+-- alter rg2 memory_limit so last query has enough memory
+ALTER RESOURCE GROUP rg2_memory_test SET memory_limit 20;
+--  system free chunks: 100% - 10% - 30% - 30% - 20% => 10%
+--  memory available to one slot in rg1/rg2: 15% + 0 + 10% => 25%
+
+--	enough memory for allocating
+1: SET ROLE TO role1_memory_test;
+1: SELECT hold_memory_by_percent(0.2 / 0.3);
+1q:
+
+--	7b) on QEs
+--	not enough memory
+ALTER RESOURCE GROUP rg2_memory_test SET memory_limit 30;
+1: SET ROLE TO role1_memory_test;
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.2 / 0.3)=0;
+1q:
+
+-- alter rg2 memory_limit so last query has enough memory
+ALTER RESOURCE GROUP rg2_memory_test SET memory_limit 20;
+--  system free chunks: 100% - 10% - 30% - 30% - 20% => 10%
+--  memory available to one slot in rg1/rg2: 15% + 0 + 10% => 25%
+
+--	enough memory for allocating
+1: SET ROLE TO role1_memory_test;
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.2 / 0.3)=0;
+1q:
+
+DROP ROLE role1_memory_test;
+DROP ROLE role2_memory_test;
+DROP RESOURCE GROUP rg1_memory_test;
+DROP RESOURCE GROUP rg2_memory_test;
+
diff --git a/src/test/isolation2/input/resgroup/resgroup_memory_statistic.source b/src/test/isolation2/input/resgroup/resgroup_memory_statistic.source
index dfc1752830cbf24080ff5db3a33171619ec22deb..0d7ba431603a02ab64842cef7ddeebb3ee1d022b 100644
--- a/src/test/isolation2/input/resgroup/resgroup_memory_statistic.source
+++ b/src/test/isolation2/input/resgroup/resgroup_memory_statistic.source
@@ -152,3 +152,4 @@ DROP ROLE role1_memory_test;
 DROP ROLE role2_memory_test;
 DROP RESOURCE GROUP rg1_memory_test;
 DROP RESOURCE GROUP rg2_memory_test;
+DROP VIEW memory_result;
diff --git a/src/test/isolation2/output/resgroup/resgroup_memory_limit.source b/src/test/isolation2/output/resgroup/resgroup_memory_limit.source
index b71dd36519a07d3bda98f52b2db16428cb658216..b2858d8139448f8317e4041da02cdef238e82e6f 100644
--- a/src/test/isolation2/output/resgroup/resgroup_memory_limit.source
+++ b/src/test/isolation2/output/resgroup/resgroup_memory_limit.source
@@ -3,39 +3,54 @@ DROP ROLE IF EXISTS role1_memory_test;
 DROP
 DROP RESOURCE GROUP rg1_memory_test;
 ERROR:  resource group "rg1_memory_test" does not exist
+DROP RESOURCE GROUP rg2_memory_test;
+ERROR:  resource group "rg2_memory_test" does not exist
 -- end_ignore
 
 CREATE OR REPLACE FUNCTION resGroupPalloc(float) RETURNS int AS '@abs_builddir@/../regress/regress@DLSUFFIX@', 'resGroupPalloc' LANGUAGE C READS SQL DATA;
 CREATE
 
-CREATE OR REPLACE FUNCTION hold_memory_by_percent(int, float) RETURNS int AS $$ SELECT * FROM resGroupPalloc($2) $$ LANGUAGE sql;
+CREATE OR REPLACE FUNCTION hold_memory_by_percent(float) RETURNS int AS $$ SELECT * FROM resGroupPalloc($1) $$ LANGUAGE sql;
 CREATE
 
---
--- first create the resgroup with memory_shared_quota == 0.
--- so each resgroup slot gets a fixed memory quota of 0.5.
---
+CREATE OR REPLACE VIEW rg_mem_status AS SELECT groupname, memory_limit, proposed_memory_limit, memory_shared_quota, proposed_memory_shared_quota FROM gp_toolkit.gp_resgroup_config WHERE groupname='rg1_memory_test' OR groupname='rg2_memory_test' ORDER BY groupid;
+CREATE
+
+CREATE OR REPLACE VIEW memory_result AS SELECT rsgname, memory_usage from gp_toolkit.gp_resgroup_status;
+CREATE
 
-CREATE RESOURCE GROUP rg1_memory_test WITH (concurrency=2, cpu_rate_limit=10, memory_limit=50, memory_shared_quota=0);
+--	1) single allocation
+--	Group Share Quota = 0
+--	Global Share Quota > 0
+--	Slot Quota > 0
+--	-----------------------
+
+--	we assume system total chunks is 100%
+--	rg1's expected: 100% * 52% => 52%
+--	rg1's slot quota: 52% / 2 * 2 => 52%
+--	rg1's single slot quota: 52% / 2 => 26%
+--	rg1's shared quota: %52 - %52 => %0
+--	system free chunks: 100% - 10% - 30% - 52% => 8%
+--	memory available to one slot in rg1: 52%/2 + 0% + 8% => 34%
+CREATE RESOURCE GROUP rg1_memory_test WITH (concurrency=2, cpu_rate_limit=10, memory_limit=52, memory_shared_quota=0);
 CREATE
 CREATE ROLE role1_memory_test RESOURCE GROUP rg1_memory_test;
 CREATE
 
--- 1) on QD only with memory_shared_quota == 0
-
+--	1a) on QD
 1: SET ROLE TO role1_memory_test;
 SET
-1: SELECT hold_memory_by_percent(1,0.2);
+1: SELECT hold_memory_by_percent(0.14 / 0.52);
 hold_memory_by_percent
 ----------------------
 0                     
 (1 row)
-1: SELECT hold_memory_by_percent(1,0.2);
+1: SELECT hold_memory_by_percent(0.14 / 0.52);
 hold_memory_by_percent
 ----------------------
 0                     
 (1 row)
-1: SELECT hold_memory_by_percent(1,0.2);
+1: SELECT hold_memory_by_percent(0.14 / 0.52);
 ERROR:  Out of memory
 DETAIL:  Resource group memory limit reached
 CONTEXT:  SQL function "hold_memory_by_percent" statement 1
@@ -45,17 +60,17 @@ CONTEXT:  SQL function "hold_memory_by_percent" statement 1
 SET
 1: BEGIN;
 BEGIN
-1: SELECT hold_memory_by_percent(1,0.2);
+1: SELECT hold_memory_by_percent(0.14 / 0.52);
 hold_memory_by_percent
 ----------------------
 0                     
 (1 row)
-1: SELECT hold_memory_by_percent(1,0.2);
+1: SELECT hold_memory_by_percent(0.14 / 0.52);
 hold_memory_by_percent
 ----------------------
 0                     
 (1 row)
-1: SELECT hold_memory_by_percent(1,0.2);
+1: SELECT hold_memory_by_percent(0.14 / 0.52);
 ERROR:  Out of memory
 DETAIL:  Resource group memory limit reached
 CONTEXT:  SQL function "hold_memory_by_percent" statement 1
@@ -63,12 +78,82 @@ CONTEXT:  SQL function "hold_memory_by_percent" statement 1
 
 1: SET ROLE TO role1_memory_test;
 SET
-1: SELECT hold_memory_by_percent(1,0.45);
+1: SELECT hold_memory_by_percent(0.42 / 0.52);
+ERROR:  Out of memory
+DETAIL:  Resource group memory limit reached
+CONTEXT:  SQL function "hold_memory_by_percent" statement 1
+1q: ... <quitting>
+
+--	1b) on QEs
+1: SET ROLE TO role1_memory_test;
+SET
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.14 / 0.52)=0;
+count
+-----
+0    
+(1 row)
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.14 / 0.52)=0;
+count
+-----
+0    
+(1 row)
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.14 / 0.52)=0;
+ERROR:  Out of memory  (seg0 slice1 10.152.10.56:25432 pid=18610)
+DETAIL:  Resource group memory limit reached
+CONTEXT:  SQL function "hold_memory_by_percent" statement 1
+1q: ... <quitting>
+
+1: SET ROLE TO role1_memory_test;
+SET
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.42 / 0.52)=0;
+ERROR:  Out of memory  (seg0 slice1 10.152.10.56:25432 pid=18619)
+DETAIL:  Resource group memory limit reached
+CONTEXT:  SQL function "hold_memory_by_percent" statement 1
+1q: ... <quitting>
+
+DROP ROLE role1_memory_test;
+DROP
+DROP RESOURCE GROUP rg1_memory_test;
+DROP
+
+--	2) single allocation
+--	Group Share Quota > 0
+--	Global Share Quota > 0
+--	Slot Quota > 0
+--	-----------------------
+
+--	we assume system total chunks is 100%
+--	rg1's expected: 100% * 52 / 100 => 52%
+--	rg1's slot quota: 52% * 60 /100 => 31%
+--	rg1's single slot quota: 31% / 2 => 15.5%
+--	rg1's shared quota: 52% - 31% => 21%
+--	system free chunks: 100% - 10% - 30% - 52% => 8%
+--	memory available to one slot in rg1: 15.5% + 21% + 8% => 44.5%
+
+CREATE RESOURCE GROUP rg1_memory_test WITH (concurrency=2, cpu_rate_limit=10, memory_limit=52, memory_shared_quota=40);
+CREATE
+CREATE ROLE role1_memory_test RESOURCE GROUP rg1_memory_test;
+CREATE
+
+--	2a) on QD
+1: SET ROLE TO role1_memory_test;
+SET
+1: SELECT hold_memory_by_percent(0.12 / 0.52);
+hold_memory_by_percent
+----------------------
+0                     
+(1 row)
+1: SELECT hold_memory_by_percent(0.12 / 0.52);
 hold_memory_by_percent
 ----------------------
 0                     
 (1 row)
-1: SELECT hold_memory_by_percent(1,0.45);
+1: SELECT hold_memory_by_percent(0.12 / 0.52);
+hold_memory_by_percent
+----------------------
+0                     
+(1 row)
+1: SELECT hold_memory_by_percent(0.12 / 0.52);
 ERROR:  Out of memory
 DETAIL:  Resource group memory limit reached
 CONTEXT:  SQL function "hold_memory_by_percent" statement 1
@@ -78,12 +163,22 @@ CONTEXT:  SQL function "hold_memory_by_percent" statement 1
 SET
 1: BEGIN;
 BEGIN
-1: SELECT hold_memory_by_percent(1,0.45);
+1: SELECT hold_memory_by_percent(0.12 / 0.52);
+hold_memory_by_percent
+----------------------
+0                     
+(1 row)
+1: SELECT hold_memory_by_percent(0.12 / 0.52);
 hold_memory_by_percent
 ----------------------
 0                     
 (1 row)
-1: SELECT hold_memory_by_percent(1,0.45);
+1: SELECT hold_memory_by_percent(0.12 / 0.52);
+hold_memory_by_percent
+----------------------
+0                     
+(1 row)
+1: SELECT hold_memory_by_percent(0.12 / 0.52);
 ERROR:  Out of memory
 DETAIL:  Resource group memory limit reached
 CONTEXT:  SQL function "hold_memory_by_percent" statement 1
@@ -91,288 +186,739 @@ CONTEXT:  SQL function "hold_memory_by_percent" statement 1
 
 1: SET ROLE TO role1_memory_test;
 SET
-1: SELECT hold_memory_by_percent(1,0.55);
+1: SELECT hold_memory_by_percent(0.48 / 0.52);
 ERROR:  Out of memory
 DETAIL:  Resource group memory limit reached
 CONTEXT:  SQL function "hold_memory_by_percent" statement 1
 1q: ... <quitting>
 
--- 2) on QEs with memory_shared_quota == 0
-
+--	2b) on QEs
 1: SET ROLE TO role1_memory_test;
 SET
-1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.2)=0;
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.12 / 0.52)=0;
 count
 -----
 0    
 (1 row)
-1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.2)=0;
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.12 / 0.52)=0;
 count
 -----
 0    
 (1 row)
-1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.2)=0;
-ERROR:  Out of memory  (seg0 slice1 172.17.0.3:25432 pid=158454)
-DETAIL:  Resource group memory limit reached
-CONTEXT:  SQL function "hold_memory_by_percent" statement 1
-1q: ... <quitting>
-
-1: SET ROLE TO role1_memory_test;
-SET
-1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.45)=0;
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.12 / 0.52)=0;
 count
 -----
 0    
 (1 row)
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.12 / 0.52)=0;
+ERROR:  Out of memory  (seg0 slice1 10.152.10.56:25432 pid=19259)
+DETAIL:  Resource group memory limit reached
+CONTEXT:  SQL function "hold_memory_by_percent" statement 1
 1q: ... <quitting>
 
 1: SET ROLE TO role1_memory_test;
 SET
-1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.55)=0;
-ERROR:  Out of memory  (seg0 slice1 172.17.0.3:25432 pid=158468)
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.48 / 0.52)=0;
+ERROR:  Out of memory  (seg0 slice1 10.152.10.56:25432 pid=19269)
 DETAIL:  Resource group memory limit reached
 CONTEXT:  SQL function "hold_memory_by_percent" statement 1
 1q: ... <quitting>
 
---
--- now recreate the resgroup with memory_shared_quota > 0.
--- so each resgroup slot gets a fixed memory quota of 0.3,
--- there is also a shared memory pool of 0.4, so the actual
--- memory usage in each slot can be 0.3~0.7.
---
-
 DROP ROLE role1_memory_test;
 DROP
 DROP RESOURCE GROUP rg1_memory_test;
 DROP
-CREATE RESOURCE GROUP rg1_memory_test WITH (concurrency=2, cpu_rate_limit=10, memory_limit=10, memory_shared_quota=40);
+
+--	3) single allocation
+--	Group Share Quota > 0
+--	Global Share Quota > 0
+--	Slot Quota = 0
+--	-----------------------
+
+--	we assume system total chunks is 100%
+--	rg1's expected: 100% * 52 / 100 => 52%
+--	rg1's slot quota: 0
+--	rg1's shared quota: 52%
+--	system free chunks: 100% - 10% - 30% - 52% => 8%
+--	memory available to one slot in rg1: 52% + 8% => 60%
+
+CREATE RESOURCE GROUP rg1_memory_test WITH (concurrency=2, cpu_rate_limit=10, memory_limit=52, memory_shared_quota=100);
 CREATE
 CREATE ROLE role1_memory_test RESOURCE GROUP rg1_memory_test;
 CREATE
 
--- 3) on QD with memory_shared_quota > 0
+--	3a) on QD
+1: SET ROLE TO role1_memory_test;
+SET
+1: SELECT hold_memory_by_percent(0.25 / 0.52);
+hold_memory_by_percent
+----------------------
+0                     
+(1 row)
+1: SELECT hold_memory_by_percent(0.25 / 0.52);
+hold_memory_by_percent
+----------------------
+0                     
+(1 row)
+1: SELECT hold_memory_by_percent(0.25 / 0.52);
+ERROR:  Out of memory
+DETAIL:  Resource group memory limit reached
+CONTEXT:  SQL function "hold_memory_by_percent" statement 1
+1q: ... <quitting>
 
 1: SET ROLE TO role1_memory_test;
 SET
-1: SELECT hold_memory_by_percent(1,0.65);
+1: BEGIN;
+BEGIN
+1: SELECT hold_memory_by_percent(0.25 / 0.52);
 hold_memory_by_percent
 ----------------------
 0                     
 (1 row)
+1: SELECT hold_memory_by_percent(0.25 / 0.52);
+hold_memory_by_percent
+----------------------
+0                     
+(1 row)
+1: SELECT hold_memory_by_percent(0.25 / 0.52);
+ERROR:  Out of memory
+DETAIL:  Resource group memory limit reached
+CONTEXT:  SQL function "hold_memory_by_percent" statement 1
 1q: ... <quitting>
 
 1: SET ROLE TO role1_memory_test;
 SET
-1: SELECT hold_memory_by_percent(1,0.75);
+1: SELECT hold_memory_by_percent(0.75 / 0.52);
 ERROR:  Out of memory
 DETAIL:  Resource group memory limit reached
 CONTEXT:  SQL function "hold_memory_by_percent" statement 1
 1q: ... <quitting>
 
+--	3b) on QEs
 1: SET ROLE TO role1_memory_test;
 SET
-1: SELECT hold_memory_by_percent(1,0.2);
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.25 / 0.52)=0;
+count
+-----
+0    
+(1 row)
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.25 / 0.52)=0;
+count
+-----
+0    
+(1 row)
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.25 / 0.52)=0;
+ERROR:  Out of memory  (seg0 slice1 10.152.10.56:25432 pid=19875)
+DETAIL:  Resource group memory limit reached
+CONTEXT:  SQL function "hold_memory_by_percent" statement 1
+1q: ... <quitting>
+
+1: SET ROLE TO role1_memory_test;
+SET
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.75 / 0.52)=0;
+ERROR:  Out of memory  (seg0 slice1 10.152.10.56:25432 pid=19884)
+DETAIL:  Resource group memory limit reached
+CONTEXT:  SQL function "hold_memory_by_percent" statement 1
+1q: ... <quitting>
+
+DROP ROLE role1_memory_test;
+DROP
+DROP RESOURCE GROUP rg1_memory_test;
+DROP
+
+--	4) multi allocation in one group
+--	Group Share Quota = 0
+--	Global Share Quota > 0
+--	Slot Quota > 0
+--	-----------------------
+
+--	we assume system total chunks is 100%
+--	rg1's expected: 100% * 52 / 100 => 52%
+--	rg1's slot quota: 52% / 2 * 2 => 52%
+--	rg1's single slot quota: 52% / 2 => 26%
+--	rg1's shared quota: 0
+--	system free chunks: 100% - 10% - 30% - 52% => 8%
+--	memory available to one slot in rg1: 26% + 8% => 34%
+
+CREATE RESOURCE GROUP rg1_memory_test WITH (concurrency=2, cpu_rate_limit=10, memory_limit=52, memory_shared_quota=0);
+CREATE
+CREATE ROLE role1_memory_test RESOURCE GROUP rg1_memory_test;
+CREATE
+
+--	4a) on QD
+--	not exceed the global share
+1: SET ROLE TO role1_memory_test;
+SET
+2: SET ROLE TO role1_memory_test;
+SET
+1: BEGIN;
+BEGIN
+2: BEGIN;
+BEGIN
+1: SELECT hold_memory_by_percent(0.28 / 0.52);
 hold_memory_by_percent
 ----------------------
 0                     
 (1 row)
-1: SELECT hold_memory_by_percent(1,0.2);
+2: SELECT hold_memory_by_percent(0.28 / 0.52);
 hold_memory_by_percent
 ----------------------
 0                     
 (1 row)
-1: SELECT hold_memory_by_percent(1,0.2);
+1q: ... <quitting>
+2q: ... <quitting>
+
+--	exceed the global share
+1: SET ROLE TO role1_memory_test;
+SET
+2: SET ROLE TO role1_memory_test;
+SET
+1: BEGIN;
+BEGIN
+2: BEGIN;
+BEGIN
+1: SELECT hold_memory_by_percent(0.32 / 0.52);
 hold_memory_by_percent
 ----------------------
 0                     
 (1 row)
-1: SELECT hold_memory_by_percent(1,0.2);
+2: SELECT hold_memory_by_percent(0.32 / 0.52);
 ERROR:  Out of memory
 DETAIL:  Resource group memory limit reached
 CONTEXT:  SQL function "hold_memory_by_percent" statement 1
 1q: ... <quitting>
+2q: ... <quitting>
 
--- 4) on QEs with memory_shared_quota > 0
+--	allocate serially
+1: SET ROLE TO role1_memory_test;
+SET
+2: SET ROLE TO role1_memory_test;
+SET
+1: BEGIN;
+BEGIN
+2: BEGIN;
+BEGIN
+1: SELECT hold_memory_by_percent(0.32 / 0.52);
+hold_memory_by_percent
+----------------------
+0                     
+(1 row)
+1q: ... <quitting>
+SELECT pg_sleep(1);
+pg_sleep
+--------
+        
+(1 row)
+2: SELECT hold_memory_by_percent(0.32 / 0.52);
+hold_memory_by_percent
+----------------------
+0                     
+(1 row)
+2q: ... <quitting>
 
+--	4b) on QEs
+--	not exceed the global share
 1: SET ROLE TO role1_memory_test;
 SET
-1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.2)=0;
+2: SET ROLE TO role1_memory_test;
+SET
+1: BEGIN;
+BEGIN
+2: BEGIN;
+BEGIN
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.28 / 0.52)=0;
 count
 -----
 0    
 (1 row)
-1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.2)=0;
+2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.28 / 0.52)=0;
 count
 -----
 0    
 (1 row)
-1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.2)=0;
+1q: ... <quitting>
+2q: ... <quitting>
+
+--	exceed the global share
+1: SET ROLE TO role1_memory_test;
+SET
+2: SET ROLE TO role1_memory_test;
+SET
+1: BEGIN;
+BEGIN
+2: BEGIN;
+BEGIN
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.32 / 0.52)=0;
 count
 -----
 0    
 (1 row)
-1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.2)=0;
-ERROR:  Out of memory  (seg0 slice1 172.17.0.3:25432 pid=158496)
+2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.32 / 0.52)=0;
+ERROR:  Out of memory  (seg0 slice1 10.152.10.56:25432 pid=21102)
 DETAIL:  Resource group memory limit reached
 CONTEXT:  SQL function "hold_memory_by_percent" statement 1
 1q: ... <quitting>
+2q: ... <quitting>
 
--- 5) QD: concurrent transactions in same group with memory_shared_quota > 0
-
+--	allocate serially
 1: SET ROLE TO role1_memory_test;
 SET
+2: SET ROLE TO role1_memory_test;
+SET
 1: BEGIN;
 BEGIN
-1: SELECT hold_memory_by_percent(1,0.6);
-hold_memory_by_percent
-----------------------
-0                     
+2: BEGIN;
+BEGIN
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.32 / 0.52)=0;
+count
+-----
+0    
 (1 row)
+1q: ... <quitting>
+SELECT pg_sleep(1);
+pg_sleep
+--------
+        
+(1 row)
+2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.32 / 0.52)=0;
+count
+-----
+0    
+(1 row)
+2q: ... <quitting>
+
+DROP ROLE role1_memory_test;
+DROP
+DROP RESOURCE GROUP rg1_memory_test;
+DROP
+
+--	5) multi allocation in one group
+--	Group Share Quota > 0
+--	Global Share Quota > 0
+--	Slot Quota > 0
+--	-----------------------
+
+--	we assume system total chunks is 100%
+--	rg1's expected: 100% * 52 / 100 => 52%
+--	rg1's slot quota: 52% * 50 / 100 => 26%
+--	rg1's single slot quota: 26% / 2 => 13%
+--	rg1's shared quota: 52% - 13% * 2 => 26%
+--	system free chunks: 100% - 10% - 30% - 52% => 8%
+--	memory available to one slot in rg1: 13% + 26% + 8% => 47%
+
+CREATE RESOURCE GROUP rg1_memory_test WITH (concurrency=2, cpu_rate_limit=10, memory_limit=52, memory_shared_quota=50);
+CREATE
+CREATE ROLE role1_memory_test RESOURCE GROUP rg1_memory_test;
+CREATE
+
+--	5a) on QD
+--	not exceed the global share
+1: SET ROLE TO role1_memory_test;
+SET
 2: SET ROLE TO role1_memory_test;
 SET
+1: BEGIN;
+BEGIN
 2: BEGIN;
 BEGIN
-2: SELECT hold_memory_by_percent(1,0.3);
+-- reserve all the group shared quota
+1: SELECT hold_memory_by_percent(0.39 / 0.52);
+hold_memory_by_percent
+----------------------
+0                     
+(1 row)
+-- must allocate from global share
+2: SELECT hold_memory_by_percent(0.2 / 0.52);
 hold_memory_by_percent
 ----------------------
 0                     
 (1 row)
+1q: ... <quitting>
 2q: ... <quitting>
+
+--	exceed the global share
+1: SET ROLE TO role1_memory_test;
+SET
 2: SET ROLE TO role1_memory_test;
 SET
+1: BEGIN;
+BEGIN
 2: BEGIN;
 BEGIN
-2: SELECT hold_memory_by_percent(1,0.3);
+1: SELECT hold_memory_by_percent(0.39 / 0.52);
 hold_memory_by_percent
 ----------------------
 0                     
 (1 row)
-2: SELECT hold_memory_by_percent(1,0.2);
+2: SELECT hold_memory_by_percent(0.39 / 0.52);
 ERROR:  Out of memory
 DETAIL:  Resource group memory limit reached
 CONTEXT:  SQL function "hold_memory_by_percent" statement 1
-2q: ... <quitting>
 1q: ... <quitting>
+2q: ... <quitting>
 
--- 6) QE: concurrent transactions in same group with memory_shared_quota > 0
+--	allocate serially
+1: SET ROLE TO role1_memory_test;
+SET
+2: SET ROLE TO role1_memory_test;
+SET
+1: BEGIN;
+BEGIN
+2: BEGIN;
+BEGIN
+1: SELECT hold_memory_by_percent(0.39 / 0.52);
+hold_memory_by_percent
+----------------------
+0                     
+(1 row)
+1q: ... <quitting>
+SELECT pg_sleep(1);
+pg_sleep
+--------
+        
+(1 row)
+2: SELECT hold_memory_by_percent(0.39 / 0.52);
+hold_memory_by_percent
+----------------------
+0                     
+(1 row)
+2q: ... <quitting>
 
+--	5b) on QEs
+--	not exceed the global share
 1: SET ROLE TO role1_memory_test;
 SET
+2: SET ROLE TO role1_memory_test;
+SET
 1: BEGIN;
 BEGIN
-1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.6)=0;
+2: BEGIN;
+BEGIN
+-- reserve all the group shared quota
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.39 / 0.52)=0;
 count
 -----
 0    
 (1 row)
+-- must allocate from global share
+2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.2 / 0.52)=0;
+count
+-----
+0    
+(1 row)
+1q: ... <quitting>
+2q: ... <quitting>
+
+--	exceed the global share
+1: SET ROLE TO role1_memory_test;
+SET
 2: SET ROLE TO role1_memory_test;
 SET
+1: BEGIN;
+BEGIN
 2: BEGIN;
 BEGIN
-2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.3)=0;
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.39 / 0.52)=0;
 count
 -----
 0    
 (1 row)
+2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.39 / 0.52)=0;
+ERROR:  Out of memory  (seg0 slice1 10.152.10.56:25432 pid=21783)
+DETAIL:  Resource group memory limit reached
+CONTEXT:  SQL function "hold_memory_by_percent" statement 1
+1q: ... <quitting>
 2q: ... <quitting>
+
+--	allocate serially
+1: SET ROLE TO role1_memory_test;
+SET
 2: SET ROLE TO role1_memory_test;
 SET
+1: BEGIN;
+BEGIN
 2: BEGIN;
 BEGIN
-2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.3)=0;
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.39 / 0.52)=0;
 count
 -----
 0    
 (1 row)
-2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.2)=0;
-ERROR:  Out of memory  (seg0 slice1 172.17.0.3:25432 pid=158538)
-DETAIL:  Resource group memory limit reached
-CONTEXT:  SQL function "hold_memory_by_percent" statement 1
-2q: ... <quitting>
 1q: ... <quitting>
+SELECT pg_sleep(1);
+pg_sleep
+--------
+        
+(1 row)
+2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.39 / 0.52)=0;
+count
+-----
+0    
+(1 row)
+2q: ... <quitting>
 
--- 7) QD: concurrent transactions in same group with memory_shared_quota = 100
+DROP ROLE role1_memory_test;
+DROP
+DROP RESOURCE GROUP rg1_memory_test;
+DROP
 
-ALTER RESOURCE GROUP rg1_memory_test SET memory_shared_quota 100;
-ALTER
+--	6) multi allocation in different group
+--	Group Share Quota > 0
+--	Global Share Quota > 0
+--	Slot Quota > 0
+--	-----------------------
+
+--	we assume system total chunks is 100%
+--	rg1's expected: 100% * 20 / 100 => 20%
+--	rg1's slot quota: 20% * 60 / 100 / 2 * 2 => 12%
+--	rg1's single slot quota: 12% / 2 => 6%
+--	rg1's shared quota: 20% - 6% * 2 => 8%
+--	rg2 same as rg1
+--	system free chunks: 100% - 10% - 30% - 100%*20/100 - 100%*20/100 => 20%
+--	memory available to one slot in rg1/rg2: 6% + 8% + 20% => 34%
+
+CREATE RESOURCE GROUP rg1_memory_test WITH (concurrency=2, cpu_rate_limit=10, memory_limit=20, memory_shared_quota=40);
+CREATE
+CREATE RESOURCE GROUP rg2_memory_test WITH (concurrency=2, cpu_rate_limit=10, memory_limit=20, memory_shared_quota=40);
+CREATE
+CREATE ROLE role1_memory_test RESOURCE GROUP rg1_memory_test;
+CREATE
+CREATE ROLE role2_memory_test RESOURCE GROUP rg2_memory_test;
+CREATE
 
+--	6a) on QD
+--	not exceed the global share
 1: SET ROLE TO role1_memory_test;
 SET
+2: SET ROLE TO role2_memory_test;
+SET
 1: BEGIN;
 BEGIN
-1: SELECT hold_memory_by_percent(1,0.6);
+2: BEGIN;
+BEGIN
+1: SELECT hold_memory_by_percent(0.2 / 0.2);
 hold_memory_by_percent
 ----------------------
 0                     
 (1 row)
-2: SET ROLE TO role1_memory_test;
-SET
-2: BEGIN;
-BEGIN
-2: SELECT hold_memory_by_percent(1,0.3);
+2: SELECT hold_memory_by_percent(0.2 / 0.2);
 hold_memory_by_percent
 ----------------------
 0                     
 (1 row)
+1q: ... <quitting>
 2q: ... <quitting>
-2: SET ROLE TO role1_memory_test;
+
+--	exceed the global share
+1: SET ROLE TO role1_memory_test;
+SET
+2: SET ROLE TO role2_memory_test;
 SET
+1: BEGIN;
+BEGIN
 2: BEGIN;
 BEGIN
-2: SELECT hold_memory_by_percent(1,0.3);
+1: SELECT hold_memory_by_percent(0.3 / 0.2);
 hold_memory_by_percent
 ----------------------
 0                     
 (1 row)
-2: SELECT hold_memory_by_percent(1,0.2);
+2: SELECT hold_memory_by_percent(0.3 / 0.2);
 ERROR:  Out of memory
 DETAIL:  Resource group memory limit reached
 CONTEXT:  SQL function "hold_memory_by_percent" statement 1
-2q: ... <quitting>
 1q: ... <quitting>
+2q: ... <quitting>
 
--- 8) QE: concurrent transactions in same group with memory_shared_quota = 100
-
-ALTER RESOURCE GROUP rg1_memory_test SET memory_shared_quota 100;
-ALTER
+--	allocate serially
+1: SET ROLE TO role1_memory_test;
+SET
+2: SET ROLE TO role2_memory_test;
+SET
+1: BEGIN;
+BEGIN
+2: BEGIN;
+BEGIN
+1: SELECT hold_memory_by_percent(0.3 / 0.2);
+hold_memory_by_percent
+----------------------
+0                     
+(1 row)
+1q: ... <quitting>
+SELECT pg_sleep(1);
+pg_sleep
+--------
+        
+(1 row)
+2: SELECT hold_memory_by_percent(0.3 / 0.2);
+hold_memory_by_percent
+----------------------
+0                     
+(1 row)
+2q: ... <quitting>
 
+--	6b) on QEs
+--	not exceed the global share
 1: SET ROLE TO role1_memory_test;
 SET
+2: SET ROLE TO role2_memory_test;
+SET
 1: BEGIN;
 BEGIN
-1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.6)=0;
+2: BEGIN;
+BEGIN
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.2 / 0.2)=0;
 count
 -----
 0    
 (1 row)
-2: SET ROLE TO role1_memory_test;
+2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.2 / 0.2)=0;
+count
+-----
+0    
+(1 row)
+1q: ... <quitting>
+2q: ... <quitting>
+
+--	exceed the global share
+1: SET ROLE TO role1_memory_test;
+SET
+2: SET ROLE TO role2_memory_test;
 SET
+1: BEGIN;
+BEGIN
 2: BEGIN;
 BEGIN
-2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.3)=0;
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.3 / 0.2)=0;
 count
 -----
 0    
 (1 row)
+2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.3 / 0.2)=0;
+ERROR:  Out of memory  (seg0 slice1 10.152.10.56:25432 pid=22464)
+DETAIL:  Resource group memory limit reached
+CONTEXT:  SQL function "hold_memory_by_percent" statement 1
+1q: ... <quitting>
 2q: ... <quitting>
-2: SET ROLE TO role1_memory_test;
+
+--	allocate serially
+1: SET ROLE TO role1_memory_test;
+SET
+2: SET ROLE TO role2_memory_test;
 SET
+1: BEGIN;
+BEGIN
 2: BEGIN;
 BEGIN
-2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.3)=0;
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.3 / 0.2)=0;
+count
+-----
+0    
+(1 row)
+1q: ... <quitting>
+SELECT pg_sleep(1);
+pg_sleep
+--------
+        
+(1 row)
+2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.3 / 0.2)=0;
 count
 -----
 0    
 (1 row)
-2: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(t1.dbid,0.2)=0;
-ERROR:  Out of memory  (seg0 slice1 192.168.99.102:25432 pid=18476)
+2q: ... <quitting>
+
+DROP ROLE role1_memory_test;
+DROP
+DROP ROLE role2_memory_test;
+DROP
+DROP RESOURCE GROUP rg1_memory_test;
+DROP
+DROP RESOURCE GROUP rg2_memory_test;
+DROP
+
+--	7) DBA can increase global shared memory by decreasing
+--		any existing group_memory_limit
+--	-----------------------
+
+--	we assume system total chunks is 100%
+--	rg1's expected: 100% * 30 / 100 => 30%
+--	rg1's slot quota: 30%
+--	rg1's single slot quota: 30% / 2 => 15%
+--	rg1's shared quota: 0
+--	rg2 same as rg1
+--	system free chunks: 100% - 10% - 30% - 30% - 30% => 0
+--	memory available to one slot in rg1/rg2: 15% + 0 + 0 => 15%
+
+CREATE RESOURCE GROUP rg1_memory_test WITH (concurrency=2, cpu_rate_limit=10, memory_limit=30, memory_shared_quota=0);
+CREATE
+CREATE RESOURCE GROUP rg2_memory_test WITH (concurrency=2, cpu_rate_limit=10, memory_limit=30, memory_shared_quota=0);
+CREATE
+CREATE ROLE role1_memory_test RESOURCE GROUP rg1_memory_test;
+CREATE
+CREATE ROLE role2_memory_test RESOURCE GROUP rg2_memory_test;
+CREATE
+
+--	7a) on QD
+--	not enough memory
+1: SET ROLE TO role1_memory_test;
+SET
+1: SELECT hold_memory_by_percent(0.2 / 0.3);
+ERROR:  Out of memory
 DETAIL:  Resource group memory limit reached
 CONTEXT:  SQL function "hold_memory_by_percent" statement 1
-2q: ... <quitting>
 1q: ... <quitting>
 
--- cleanup
+-- alter rg2 memory_limit so last query has enough memory
+ALTER RESOURCE GROUP rg2_memory_test SET memory_limit 20;
+ALTER
+--  system free chunks: 100% - 10% - 30% - 30% - 20% => 10%
+--  memory available to one slot in rg1/rg2: 15% + 0 + 10% => 25%
+
+--	enough memory for allocating
+1: SET ROLE TO role1_memory_test;
+SET
+1: SELECT hold_memory_by_percent(0.2 / 0.3);
+hold_memory_by_percent
+----------------------
+0                     
+(1 row)
+1q: ... <quitting>
+
+--	7b) on QEs
+--	not enough memory
+ALTER RESOURCE GROUP rg2_memory_test SET memory_limit 30;
+ALTER
+1: SET ROLE TO role1_memory_test;
+SET
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.2 / 0.3)=0;
+ERROR:  Out of memory  (seg0 slice1 10.152.10.56:25432 pid=23131)
+DETAIL:  Resource group memory limit reached
+CONTEXT:  SQL function "hold_memory_by_percent" statement 1
+1q: ... <quitting>
+
+-- alter rg2 memory_limit so last query has enough memory
+ALTER RESOURCE GROUP rg2_memory_test SET memory_limit 20;
+ALTER
+--  system free chunks: 100% - 10% - 30% - 30% - 20% => 10%
+--  memory available to one slot in rg1/rg2: 15% + 0 + 10% => 25%
+
+--	enough memory for allocating
+1: SET ROLE TO role1_memory_test;
+SET
+1: SELECT count(null) FROM gp_dist_random('gp_id') t1 WHERE hold_memory_by_percent(0.2 / 0.3)=0;
+count
+-----
+0    
+(1 row)
+1q: ... <quitting>
+
 DROP ROLE role1_memory_test;
 DROP
+DROP ROLE role2_memory_test;
+DROP
 DROP RESOURCE GROUP rg1_memory_test;
 DROP
+DROP RESOURCE GROUP rg2_memory_test;
+DROP
+
diff --git a/src/test/isolation2/output/resgroup/resgroup_memory_statistic.source b/src/test/isolation2/output/resgroup/resgroup_memory_statistic.source
index db13567302c20dc88598bf41019e92f0aec81468..7243333bdfede42b105282d2dff9106158cf6736 100644
--- a/src/test/isolation2/output/resgroup/resgroup_memory_statistic.source
+++ b/src/test/isolation2/output/resgroup/resgroup_memory_statistic.source
@@ -298,3 +298,5 @@ DROP RESOURCE GROUP rg1_memory_test;
 DROP
 DROP RESOURCE GROUP rg2_memory_test;
 DROP
+DROP VIEW memory_result;
+DROP
diff --git a/src/test/isolation2/sql/resgroup/resgroup_alter_memory_spill_ratio.sql b/src/test/isolation2/sql/resgroup/resgroup_alter_memory_spill_ratio.sql
index 2423cfcf63a6893d9b54ae17d8602a6a3460e1fb..de53f2ed513a2cf17e14c6950a669af33d501f31 100644
--- a/src/test/isolation2/sql/resgroup/resgroup_alter_memory_spill_ratio.sql
+++ b/src/test/isolation2/sql/resgroup/resgroup_alter_memory_spill_ratio.sql
@@ -17,7 +17,7 @@ SELECT * FROM rg_spill_status;
 ALTER RESOURCE GROUP rg_spill_test SET MEMORY_SPILL_RATIO 20;
 SELECT * FROM rg_spill_status;
 
--- positive, memory_spill_ratio range is [0, 100]
+-- positive, memory_spill_ratio range is [0, 2147483647]
 ALTER RESOURCE GROUP rg_spill_test SET MEMORY_SPILL_RATIO 0;
 SELECT * FROM rg_spill_status;
 
@@ -30,8 +30,8 @@ ALTER RESOURCE GROUP rg_spill_test SET MEMORY_SPILL_RATIO 20.0;
 ALTER RESOURCE GROUP rg_spill_test SET MEMORY_SPILL_RATIO a;
 SELECT * FROM rg_spill_status;
 
--- negative: memory_spill_ratio is larger than RESGROUP_MAX_MEMORY_SPILL_RATIO
-ALTER RESOURCE GROUP rg_spill_test SET MEMORY_SPILL_RATIO 101;
+-- negative: memory_spill_ratio is negative
+ALTER RESOURCE GROUP rg_spill_test SET MEMORY_SPILL_RATIO -1;
 SELECT * FROM rg_spill_status;
 
 -- cleanup
diff --git a/src/test/isolation2/sql/resgroup/resgroup_set_memory_spill_ratio.sql b/src/test/isolation2/sql/resgroup/resgroup_set_memory_spill_ratio.sql
index 9194ff7e167dd121a8b80ae9402c4f48964fba6f..9765851b1a7f8ac6f5d4951ad70a92ef16a510a8 100644
--- a/src/test/isolation2/sql/resgroup/resgroup_set_memory_spill_ratio.sql
+++ b/src/test/isolation2/sql/resgroup/resgroup_set_memory_spill_ratio.sql
@@ -30,7 +30,7 @@ SHOW MEMORY_SPILL_RATIO;
 SELECT 1;
 
 -- negative set to session level
-SET MEMORY_SPILL_RATIO TO 101;
+SET MEMORY_SPILL_RATIO TO -1;
 SHOW MEMORY_SPILL_RATIO;
 SELECT 1;
 
diff --git a/src/test/isolation2/sql/resgroup/resgroup_syntax.sql b/src/test/isolation2/sql/resgroup/resgroup_syntax.sql
index 5b70afd648c8675394f3e8f59be82a1d5fe00a71..6b579e96104de3a3601b8217dfb9c33a02f7ef1d 100644
--- a/src/test/isolation2/sql/resgroup/resgroup_syntax.sql
+++ b/src/test/isolation2/sql/resgroup/resgroup_syntax.sql
@@ -95,7 +95,7 @@ CREATE RESOURCE GROUP rg_test_group WITH (concurrency=0, cpu_rate_limit=10, memo
 -- negative: concurrency should be zero for cgroup audited resource group
 CREATE RESOURCE GROUP rg_test_group WITH (concurrency=1, cpu_rate_limit=10, memory_limit=10, memory_auditor="cgroup");
 
--- memory_spill_ratio range is [0, 100]
+-- memory_spill_ratio range is [0, 2147483647]
 -- no limit on the sum of memory_shared_quota and memory_spill_ratio
 CREATE RESOURCE GROUP rg_test_group WITH (cpu_rate_limit=10, memory_limit=10, memory_shared_quota=10, memory_spill_ratio=0);
 DROP RESOURCE GROUP rg_test_group;
@@ -136,7 +136,7 @@ DROP RESOURCE GROUP rg2_test_group;
 CREATE RESOURCE GROUP rg_test_group WITH (concurrency=0, cpu_rate_limit=10, memory_limit=10, memory_auditor="cgroup");
 DROP RESOURCE GROUP rg_test_group;
 
--- memory_spill_ratio range is [0, 100]
+-- memory_spill_ratio range is [0, 2147483647]
 -- no limit on the sum of memory_shared_quota and memory_spill_ratio
 CREATE RESOURCE GROUP rg_test_group WITH (cpu_rate_limit=10, memory_limit=10, memory_shared_quota=0, memory_spill_ratio=1);
 DROP RESOURCE GROUP rg_test_group;
diff --git a/src/test/isolation2/sql/resgroup/resgroup_unlimit_memory_spill_ratio.sql b/src/test/isolation2/sql/resgroup/resgroup_unlimit_memory_spill_ratio.sql
index ea34f0900fe31b3143c9ef886e0277bbfd395e7a..2302e1cba1138912c76d839da36144a36199e3fc 100644
--- a/src/test/isolation2/sql/resgroup/resgroup_unlimit_memory_spill_ratio.sql
+++ b/src/test/isolation2/sql/resgroup/resgroup_unlimit_memory_spill_ratio.sql
@@ -19,10 +19,6 @@ CREATE RESOURCE GROUP rg_spill_test WITH
 (concurrency=10, cpu_rate_limit=20, memory_limit=20, memory_shared_quota=50, memory_spill_ratio=-1);
 DROP RESOURCE GROUP rg_spill_test;
 
-CREATE RESOURCE GROUP rg_spill_test WITH
-(concurrency=10, cpu_rate_limit=20, memory_limit=20, memory_shared_quota=50, memory_spill_ratio=101);
-DROP RESOURCE GROUP rg_spill_test;
-
 -- alter
 CREATE RESOURCE GROUP rg_spill_test WITH
 (concurrency=10, cpu_rate_limit=20, memory_limit=20, memory_shared_quota=50, memory_spill_ratio=20);
@@ -31,7 +27,7 @@ ALTER RESOURCE GROUP rg_spill_test SET MEMORY_SPILL_RATIO 60;
 ALTER RESOURCE GROUP rg_spill_test SET MEMORY_SPILL_RATIO 0;
 ALTER RESOURCE GROUP rg_spill_test SET MEMORY_SPILL_RATIO 100;
 ALTER RESOURCE GROUP rg_spill_test SET MEMORY_SPILL_RATIO -1;
-ALTER RESOURCE GROUP rg_spill_test SET MEMORY_SPILL_RATIO 101;
+ALTER RESOURCE GROUP rg_spill_test SET MEMORY_SPILL_RATIO 10000;
 
 DROP RESOURCE GROUP rg_spill_test;
 
@@ -55,7 +51,7 @@ SET MEMORY_SPILL_RATIO TO -1;
 SHOW MEMORY_SPILL_RATIO;
 SELECT 1;
 
-SET MEMORY_SPILL_RATIO TO 101;
+SET MEMORY_SPILL_RATIO TO 10000;
 SHOW MEMORY_SPILL_RATIO;
 SELECT 1;