From 87f94368ca564486a51b0172a3eb0f5f49180387 Mon Sep 17 00:00:00 2001
From: Koval Dmitry <d.koval@postgrespro.ru>
Date: Mon, 19 Sep 2022 16:06:03 +0300
Subject: [PATCH 1/3] ALTER TABLE MERGE PARTITIONS command

---
 src/backend/commands/tablecmds.c              | 349 ++++++++-
 src/backend/parser/gram.y                     |  22 +-
 src/backend/parser/parse_utilcmd.c            |  89 +++
 src/backend/partitioning/partbounds.c         | 207 +++++
 src/include/nodes/parsenodes.h                |  14 +
 src/include/parser/kwlist.h                   |   1 +
 src/include/partitioning/partbounds.h         |   6 +
 .../isolation/expected/partition-merge.out    | 199 +++++
 src/test/isolation/isolation_schedule         |   1 +
 src/test/isolation/specs/partition-merge.spec |  54 ++
 .../test_ddl_deparse/test_ddl_deparse.c       |   3 +
 src/test/regress/expected/partition_merge.out | 736 ++++++++++++++++++
 src/test/regress/parallel_schedule            |   2 +-
 src/test/regress/sql/partition_merge.sql      | 434 +++++++++++
 src/tools/pgindent/typedefs.list              |   1 +
 15 files changed, 2099 insertions(+), 19 deletions(-)
 create mode 100644 src/test/isolation/expected/partition-merge.out
 create mode 100644 src/test/isolation/specs/partition-merge.spec
 create mode 100644 src/test/regress/expected/partition_merge.out
 create mode 100644 src/test/regress/sql/partition_merge.sql

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 6741e721ae3..3541ebebd65 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -670,6 +670,8 @@ static void ATDetachCheckNoForeignKeyRefs(Relation partition);
 static char GetAttributeCompression(Oid atttypid, const char *compression);
 static char GetAttributeStorage(Oid atttypid, const char *storagemode);
 
+static void ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
+								  PartitionCmd *cmd, AlterTableUtilityContext *context);
 
 /* ----------------------------------------------------------------
  *		DefineRelation
@@ -4738,6 +4740,10 @@ AlterTableGetLockLevel(List *cmds)
 				cmd_lockmode = ShareUpdateExclusiveLock;
 				break;
 
+			case AT_MergePartitions:
+				cmd_lockmode = AccessExclusiveLock;
+				break;
+
 			default:			/* oops */
 				elog(ERROR, "unrecognized alter table type: %d",
 					 (int) cmd->subtype);
@@ -5157,6 +5163,11 @@ ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd,
 			/* No command-specific prep needed */
 			pass = AT_PASS_MISC;
 			break;
+		case AT_MergePartitions:
+			ATSimplePermissions(cmd->subtype, rel, ATT_TABLE);
+			/* No command-specific prep needed */
+			pass = AT_PASS_MISC;
+			break;
 		default:				/* oops */
 			elog(ERROR, "unrecognized alter table type: %d",
 				 (int) cmd->subtype);
@@ -5554,6 +5565,14 @@ ATExecCmd(List **wqueue, AlteredTableInfo *tab,
 		case AT_DetachPartitionFinalize:
 			address = ATExecDetachPartitionFinalize(rel, ((PartitionCmd *) cmd->def)->name);
 			break;
+		case AT_MergePartitions:
+			cmd = ATParseTransformCmd(wqueue, tab, rel, cmd, false, lockmode,
+									  cur_pass, context);
+			Assert(cmd != NULL);
+			Assert(rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE);
+			ATExecMergePartitions(wqueue, tab, rel, (PartitionCmd *) cmd->def,
+								  context);
+			break;
 		default:				/* oops */
 			elog(ERROR, "unrecognized alter table type: %d",
 				 (int) cmd->subtype);
@@ -6544,6 +6563,8 @@ alter_table_type_to_string(AlterTableType cmdtype)
 			return "DETACH PARTITION";
 		case AT_DetachPartitionFinalize:
 			return "DETACH PARTITION ... FINALIZE";
+		case AT_MergePartitions:
+			return "MERGE PARTITIONS";
 		case AT_AddIdentity:
 			return "ALTER COLUMN ... ADD IDENTITY";
 		case AT_SetIdentity:
@@ -19038,6 +19059,37 @@ QueuePartitionConstraintValidation(List **wqueue, Relation scanrel,
 	}
 }
 
+/*
+ * attachPartitionTable: attach new partition to partitioned table
+ *
+ * wqueue: the ALTER TABLE work queue; can be NULL when not running as part
+ *   of an ALTER TABLE sequence.
+ * rel: partitioned relation;
+ * attachrel: relation of attached partition;
+ * bound: bounds of attached relation.
+ */
+static void
+attachPartitionTable(List **wqueue, Relation rel, Relation attachrel, PartitionBoundSpec *bound)
+{
+	/* OK to create inheritance.  Rest of the checks performed there */
+	CreateInheritance(attachrel, rel, true);
+
+	/* Update the pg_class entry. */
+	StorePartitionBound(attachrel, rel, bound);
+
+	/* Ensure there exists a correct set of indexes in the partition. */
+	AttachPartitionEnsureIndexes(wqueue, rel, attachrel);
+
+	/* and triggers */
+	CloneRowTriggersToPartition(rel, attachrel);
+
+	/*
+	 * Clone foreign key constraints.  Callee is responsible for setting up
+	 * for phase 3 constraint verification.
+	 */
+	CloneForeignKeyConstraints(wqueue, rel, attachrel);
+}
+
 /*
  * ALTER TABLE <name> ATTACH PARTITION <partition-name> FOR VALUES
  *
@@ -19240,23 +19292,8 @@ ATExecAttachPartition(List **wqueue, Relation rel, PartitionCmd *cmd,
 	check_new_partition_bound(RelationGetRelationName(attachrel), rel,
 							  cmd->bound, pstate);
 
-	/* OK to create inheritance.  Rest of the checks performed there */
-	CreateInheritance(attachrel, rel, true);
-
-	/* Update the pg_class entry. */
-	StorePartitionBound(attachrel, rel, cmd->bound);
-
-	/* Ensure there exists a correct set of indexes in the partition. */
-	AttachPartitionEnsureIndexes(wqueue, rel, attachrel);
-
-	/* and triggers */
-	CloneRowTriggersToPartition(rel, attachrel);
-
-	/*
-	 * Clone foreign key constraints.  Callee is responsible for setting up
-	 * for phase 3 constraint verification.
-	 */
-	CloneForeignKeyConstraints(wqueue, rel, attachrel);
+	/* Attach a new partition to the partitioned table. */
+	attachPartitionTable(wqueue, rel, attachrel, cmd->bound);
 
 	/*
 	 * Generate partition constraint from the partition bound specification.
@@ -20810,3 +20847,281 @@ GetAttributeStorage(Oid atttypid, const char *storagemode)
 
 	return cstorage;
 }
+
+/*
+ * createPartitionTable: create table for new partition with given name
+ * (newPartName) like table (modelRelName)
+ *
+ * Emulates command: CREATE TABLE <newPartName> (LIKE <modelRelName>
+ * INCLUDING ALL EXCLUDING INDEXES EXCLUDING IDENTITY)
+ */
+static void
+createPartitionTable(RangeVar *newPartName, RangeVar *modelRelName,
+					 AlterTableUtilityContext *context)
+{
+	CreateStmt *createStmt;
+	TableLikeClause *tlc;
+	PlannedStmt *wrapper;
+
+	createStmt = makeNode(CreateStmt);
+	createStmt->relation = newPartName;
+	createStmt->tableElts = NIL;
+	createStmt->inhRelations = NIL;
+	createStmt->constraints = NIL;
+	createStmt->options = NIL;
+	createStmt->oncommit = ONCOMMIT_NOOP;
+	createStmt->tablespacename = NULL;
+	createStmt->if_not_exists = false;
+
+	tlc = makeNode(TableLikeClause);
+	tlc->relation = modelRelName;
+
+	/*
+	 * Indexes will be inherited on "attach new partitions" stage, after data
+	 * moving.
+	 */
+	tlc->options = CREATE_TABLE_LIKE_ALL & ~(CREATE_TABLE_LIKE_INDEXES | CREATE_TABLE_LIKE_IDENTITY);
+	tlc->relationOid = InvalidOid;
+	createStmt->tableElts = lappend(createStmt->tableElts, tlc);
+
+	/* Need to make a wrapper PlannedStmt. */
+	wrapper = makeNode(PlannedStmt);
+	wrapper->commandType = CMD_UTILITY;
+	wrapper->canSetTag = false;
+	wrapper->utilityStmt = (Node *) createStmt;
+	wrapper->stmt_location = context->pstmt->stmt_location;
+	wrapper->stmt_len = context->pstmt->stmt_len;
+
+	ProcessUtility(wrapper,
+				   context->queryString,
+				   false,
+				   PROCESS_UTILITY_SUBCOMMAND,
+				   NULL,
+				   NULL,
+				   None_Receiver,
+				   NULL);
+}
+
+/*
+ * moveMergedTablesRows: scan partitions to be merged (mergingPartitionsList)
+ * of the partitioned table (rel) and move rows into the new partition
+ * (newPartRel).
+ */
+static void
+moveMergedTablesRows(Relation rel, List *mergingPartitionsList,
+					 Relation newPartRel)
+{
+	CommandId	mycid;
+
+	/* The FSM is empty, so don't bother using it. */
+	int			ti_options = TABLE_INSERT_SKIP_FSM;
+	ListCell   *listptr;
+	BulkInsertState bistate;	/* state of bulk inserts for partition */
+	TupleTableSlot *dstslot;
+
+	mycid = GetCurrentCommandId(true);
+
+	/* Prepare a BulkInsertState for table_tuple_insert. */
+	bistate = GetBulkInsertState();
+
+	/* Create necessary tuple slot. */
+	dstslot = MakeSingleTupleTableSlot(RelationGetDescr(newPartRel),
+									   table_slot_callbacks(newPartRel));
+	ExecStoreAllNullTuple(dstslot);
+
+	foreach(listptr, mergingPartitionsList)
+	{
+		Relation	mergingPartition = (Relation) lfirst(listptr);
+		TupleTableSlot *srcslot;
+		TupleConversionMap *tuple_map;
+		TableScanDesc scan;
+		Snapshot	snapshot;
+
+		/* Create tuple slot for new partition. */
+		srcslot = MakeSingleTupleTableSlot(RelationGetDescr(mergingPartition),
+										   table_slot_callbacks(mergingPartition));
+
+		/*
+		 * Map computing for moving attributes of merged partition to new
+		 * partition.
+		 */
+		tuple_map = convert_tuples_by_name(RelationGetDescr(mergingPartition),
+										   RelationGetDescr(newPartRel));
+
+		/* Scan through the rows. */
+		snapshot = RegisterSnapshot(GetLatestSnapshot());
+		scan = table_beginscan(mergingPartition, snapshot, 0, NULL);
+
+		while (table_scan_getnextslot(scan, ForwardScanDirection, srcslot))
+		{
+			TupleTableSlot *insertslot;
+
+			/* Extract data from old tuple. */
+			slot_getallattrs(srcslot);
+
+			if (tuple_map)
+			{
+				/* Need to use map for copy attributes. */
+				insertslot = execute_attr_map_slot(tuple_map->attrMap, srcslot, dstslot);
+			}
+			else
+			{
+				/* Copy attributes directly. */
+				insertslot = dstslot;
+
+				ExecClearTuple(insertslot);
+
+				memcpy(insertslot->tts_values, srcslot->tts_values,
+					   sizeof(Datum) * srcslot->tts_nvalid);
+				memcpy(insertslot->tts_isnull, srcslot->tts_isnull,
+					   sizeof(bool) * srcslot->tts_nvalid);
+
+				ExecStoreVirtualTuple(insertslot);
+			}
+
+			/* Write the tuple out to the new relation. */
+			table_tuple_insert(newPartRel, insertslot, mycid, ti_options, bistate);
+
+			CHECK_FOR_INTERRUPTS();
+		}
+
+		table_endscan(scan);
+		UnregisterSnapshot(snapshot);
+
+		if (tuple_map)
+			free_conversion_map(tuple_map);
+
+		ExecDropSingleTupleTableSlot(srcslot);
+	}
+
+	ExecDropSingleTupleTableSlot(dstslot);
+	FreeBulkInsertState(bistate);
+
+	table_finish_bulk_insert(newPartRel, ti_options);
+}
+
+/*
+ * ALTER TABLE <name> MERGE PARTITIONS <partition-list> INTO <partition-name>
+ */
+static void
+ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
+					  PartitionCmd *cmd, AlterTableUtilityContext *context)
+{
+	Relation	newPartRel;
+	ListCell   *listptr;
+	List	   *mergingPartitionsList = NIL;
+	Oid			defaultPartOid;
+	char		tmpRelName[NAMEDATALEN];
+	RangeVar   *mergePartName = cmd->name;
+	bool		isSameName = false;
+
+	/*
+	 * Lock all merged partitions, check them and create list with partitions
+	 * contexts.
+	 */
+	foreach(listptr, cmd->partlist)
+	{
+		RangeVar   *name = (RangeVar *) lfirst(listptr);
+		Relation	mergingPartition;
+
+		/*
+		 * We are going to detach and remove this partition: need to use
+		 * exclusive lock for prevent DML-queries to the partition.
+		 */
+		mergingPartition = table_openrv(name, AccessExclusiveLock);
+
+		if (mergingPartition->rd_rel->relkind != RELKIND_RELATION)
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("cannot merge non-table partition \"%s\"",
+							RelationGetRelationName(mergingPartition))));
+
+		/*
+		 * Checking that two partitions have the same name was before, in
+		 * function transformPartitionCmdForMerge().
+		 */
+		if (equal(name, cmd->name))
+			/* One new partition can have the same name as merged partition. */
+			isSameName = true;
+
+		/* Store a next merging partition into the list. */
+		mergingPartitionsList = lappend(mergingPartitionsList,
+										mergingPartition);
+	}
+
+	/* Detach all merged partitions. */
+	defaultPartOid =
+		get_default_oid_from_partdesc(RelationGetPartitionDesc(rel, true));
+	foreach(listptr, mergingPartitionsList)
+	{
+		Relation	mergingPartition = (Relation) lfirst(listptr);
+
+		/* Remove the pg_inherits row first. */
+		RemoveInheritance(mergingPartition, rel, false);
+		/* Do the final part of detaching. */
+		DetachPartitionFinalize(rel, mergingPartition, false, defaultPartOid);
+	}
+
+	/* Create table for new partition, use partitioned table as model. */
+	if (isSameName)
+	{
+		/* Create partition table with generated temparary name. */
+		sprintf(tmpRelName, "merge-%u-%X-tmp", RelationGetRelid(rel), MyProcPid);
+		mergePartName = makeRangeVar(get_namespace_name(RelationGetNamespace(rel)),
+									 tmpRelName, -1);
+	}
+	createPartitionTable(mergePartName,
+						 makeRangeVar(get_namespace_name(RelationGetNamespace(rel)),
+									  RelationGetRelationName(rel), -1),
+						 context);
+
+	/*
+	 * Open the new partition and acquire exclusive lock on it.  This will
+	 * stop all the operations with partitioned table.  This might seem
+	 * excessive, but this is the way we make sure nobody is planning queries
+	 * involving merging partitions.
+	 */
+	newPartRel = table_openrv(mergePartName, AccessExclusiveLock);
+
+	/* Copy data from merged partitions to new partition. */
+	moveMergedTablesRows(rel, mergingPartitionsList, newPartRel);
+
+	/*
+	 * Attach a new partition to the partitioned table. wqueue = NULL:
+	 * verification for each cloned constraint is not need.
+	 */
+	attachPartitionTable(NULL, rel, newPartRel, cmd->bound);
+
+	/* Unlock and drop merged partitions. */
+	foreach(listptr, mergingPartitionsList)
+	{
+		ObjectAddress object;
+		Relation	mergingPartition = (Relation) lfirst(listptr);
+
+		/* Get relation id before table_close() call. */
+		object.objectId = RelationGetRelid(mergingPartition);
+		object.classId = RelationRelationId;
+		object.objectSubId = 0;
+
+		/* Keep the lock until commit. */
+		table_close(mergingPartition, NoLock);
+
+		performDeletion(&object, DROP_RESTRICT, 0);
+	}
+	list_free(mergingPartitionsList);
+
+	/* Rename new partition if it is needed. */
+	if (isSameName)
+	{
+		/*
+		 * We must bump the command counter to make the new partition tuple
+		 * visible for rename.
+		 */
+		CommandCounterIncrement();
+		/* Rename partition. */
+		RenameRelationInternal(RelationGetRelid(newPartRel),
+							   cmd->name->relname, false, false);
+	}
+	/* Keep the lock until commit. */
+	table_close(newPartRel, NoLock);
+}
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index c1b0cff1c9e..0d9d351b445 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -755,7 +755,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	ORDER ORDINALITY OTHERS OUT_P OUTER_P
 	OVER OVERLAPS OVERLAY OVERRIDING OWNED OWNER
 
-	PARALLEL PARAMETER PARSER PARTIAL PARTITION PASSING PASSWORD
+	PARALLEL PARAMETER PARSER PARTIAL PARTITION PARTITIONS PASSING PASSWORD
 	PERIOD PLACING PLANS POLICY
 	POSITION PRECEDING PRECISION PRESERVE PREPARE PREPARED PRIMARY
 	PRIOR PRIVILEGES PROCEDURAL PROCEDURE PROCEDURES PROGRAM PUBLICATION
@@ -2310,6 +2310,7 @@ partition_cmd:
 					n->subtype = AT_AttachPartition;
 					cmd->name = $3;
 					cmd->bound = $4;
+					cmd->partlist = NULL;
 					cmd->concurrent = false;
 					n->def = (Node *) cmd;
 
@@ -2324,6 +2325,7 @@ partition_cmd:
 					n->subtype = AT_DetachPartition;
 					cmd->name = $3;
 					cmd->bound = NULL;
+					cmd->partlist = NULL;
 					cmd->concurrent = $4;
 					n->def = (Node *) cmd;
 
@@ -2337,6 +2339,21 @@ partition_cmd:
 					n->subtype = AT_DetachPartitionFinalize;
 					cmd->name = $3;
 					cmd->bound = NULL;
+					cmd->partlist = NULL;
+					cmd->concurrent = false;
+					n->def = (Node *) cmd;
+					$$ = (Node *) n;
+				}
+			/* ALTER TABLE <name> MERGE PARTITIONS () INTO <partition_name> */
+			| MERGE PARTITIONS '(' qualified_name_list ')' INTO qualified_name
+				{
+					AlterTableCmd *n = makeNode(AlterTableCmd);
+					PartitionCmd *cmd = makeNode(PartitionCmd);
+
+					n->subtype = AT_MergePartitions;
+					cmd->name = $7;
+					cmd->bound = NULL;
+					cmd->partlist = $4;
 					cmd->concurrent = false;
 					n->def = (Node *) cmd;
 					$$ = (Node *) n;
@@ -2353,6 +2370,7 @@ index_partition_cmd:
 					n->subtype = AT_AttachPartition;
 					cmd->name = $3;
 					cmd->bound = NULL;
+					cmd->partlist = NULL;
 					cmd->concurrent = false;
 					n->def = (Node *) cmd;
 
@@ -17510,6 +17528,7 @@ unreserved_keyword:
 			| PARSER
 			| PARTIAL
 			| PARTITION
+			| PARTITIONS
 			| PASSING
 			| PASSWORD
 			| PERIOD
@@ -18128,6 +18147,7 @@ bare_label_keyword:
 			| PARSER
 			| PARTIAL
 			| PARTITION
+			| PARTITIONS
 			| PASSING
 			| PASSWORD
 			| PERIOD
diff --git a/src/backend/parser/parse_utilcmd.c b/src/backend/parser/parse_utilcmd.c
index c7efd8d8cee..48a23c7ca42 100644
--- a/src/backend/parser/parse_utilcmd.c
+++ b/src/backend/parser/parse_utilcmd.c
@@ -58,6 +58,8 @@
 #include "parser/parse_type.h"
 #include "parser/parse_utilcmd.h"
 #include "parser/parser.h"
+#include "partitioning/partdesc.h"
+#include "partitioning/partbounds.h"
 #include "rewrite/rewriteManip.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
@@ -3413,6 +3415,80 @@ transformRuleStmt(RuleStmt *stmt, const char *queryString,
 }
 
 
+/*
+ * transformPartitionCmdForMerge
+ *		Analyze the ALTER TABLLE ... MERGE PARTITIONS command
+ *
+ * Does simple checks for merged partitions. Calculates bound of result
+ * partition.
+ */
+static void
+transformPartitionCmdForMerge(CreateStmtContext *cxt, PartitionCmd *partcmd)
+{
+	Oid			defaultPartOid;
+	Oid			partOid;
+	Relation	parent = cxt->rel;
+	PartitionKey key;
+	char		strategy;
+	ListCell   *listptr,
+			   *listptr2;
+	bool		isDefaultPart = false;
+	List	   *partOids = NIL;
+
+	if (parent->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+				 errmsg("\"%s\" is not a partitioned table", RelationGetRelationName(parent))));
+
+	key = RelationGetPartitionKey(parent);
+	strategy = get_partition_strategy(key);
+
+	if (strategy == PARTITION_STRATEGY_HASH)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("partition of hash-partitioned table cannot be merged")));
+
+	/* Is current partition a DEFAULT partition? */
+	defaultPartOid = get_default_oid_from_partdesc(
+												   RelationGetPartitionDesc(parent, true));
+
+	foreach(listptr, partcmd->partlist)
+	{
+		RangeVar   *name = (RangeVar *) lfirst(listptr);
+
+		/* Partitions in the list should have different names. */
+		for_each_cell(listptr2, partcmd->partlist, lnext(partcmd->partlist, listptr))
+		{
+			RangeVar   *name2 = (RangeVar *) lfirst(listptr2);
+
+			if (equal(name, name2))
+				ereport(ERROR,
+						(errcode(ERRCODE_DUPLICATE_TABLE),
+						 errmsg("partition with name \"%s\" already used", name->relname)),
+						parser_errposition(cxt->pstate, name2->location));
+		}
+
+		/* Search DEFAULT partition in the list. */
+		partOid = RangeVarGetRelid(name, NoLock, false);
+		if (partOid == defaultPartOid)
+			isDefaultPart = true;
+		partOids = lappend_oid(partOids, partOid);
+	}
+
+	/* Allocate bound of result partition. */
+	Assert(partcmd->bound == NULL);
+	partcmd->bound = makeNode(PartitionBoundSpec);
+
+	/* Fill partition bound. */
+	partcmd->bound->strategy = strategy;
+	partcmd->bound->location = -1;
+	partcmd->bound->is_default = isDefaultPart;
+	if (!isDefaultPart)
+		calculate_partition_bound_for_merge(parent, partcmd->partlist,
+											partOids, partcmd->bound,
+											cxt->pstate);
+}
+
 /*
  * transformAlterTableStmt -
  *		parse analysis for ALTER TABLE
@@ -3683,6 +3759,19 @@ transformAlterTableStmt(Oid relid, AlterTableStmt *stmt,
 				newcmds = lappend(newcmds, cmd);
 				break;
 
+			case AT_MergePartitions:
+				{
+					PartitionCmd *partcmd = (PartitionCmd *) cmd->def;
+
+					if (list_length(partcmd->partlist) < 2)
+						ereport(ERROR,
+								(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+								 errmsg("list of new partitions should contains at least two items")));
+					transformPartitionCmdForMerge(&cxt, partcmd);
+					newcmds = lappend(newcmds, cmd);
+					break;
+				}
+
 			default:
 
 				/*
diff --git a/src/backend/partitioning/partbounds.c b/src/backend/partitioning/partbounds.c
index c28639d2e3f..9ed80d721ed 100644
--- a/src/backend/partitioning/partbounds.c
+++ b/src/backend/partitioning/partbounds.c
@@ -4977,3 +4977,210 @@ satisfies_hash_partition(PG_FUNCTION_ARGS)
 
 	PG_RETURN_BOOL(rowHash % modulus == remainder);
 }
+
+/*
+ * check_two_partitions_bounds_range
+ *
+ * (function for BY RANGE partitioning)
+ *
+ * This is a helper function for check_partitions_for_split() and
+ * calculate_partition_bound_for_merge().
+ * This function compares upper bound of first_bound and lower bound of
+ * second_bound. These bounds should be equals except case
+ * "defaultPart == true" (this means that one of split partitions is DEFAULT).
+ * In this case upper bound of first_bound can be less than lower bound of
+ * second_bound because space between of these bounds will be included in
+ * DEFAULT partition.
+ *
+ * parent:			partitioned table
+ * first_name:		name of first partition
+ * first_bound:		bound of first partition
+ * second_name:		name of second partition
+ * second_bound:	bound of second partition
+ * defaultPart:		true if one of split partitions is DEFAULT
+ * pstate:			pointer to ParseState struct for determine error position
+ */
+static void
+check_two_partitions_bounds_range(Relation parent,
+								  RangeVar *first_name,
+								  PartitionBoundSpec *first_bound,
+								  RangeVar *second_name,
+								  PartitionBoundSpec *second_bound,
+								  bool defaultPart,
+								  ParseState *pstate)
+{
+	PartitionKey key = RelationGetPartitionKey(parent);
+	PartitionRangeBound *first_upper;
+	PartitionRangeBound *second_lower;
+	int			cmpval;
+
+	Assert(key->strategy == PARTITION_STRATEGY_RANGE);
+
+	first_upper = make_one_partition_rbound(key, -1, first_bound->upperdatums, false);
+	second_lower = make_one_partition_rbound(key, -1, second_bound->lowerdatums, true);
+
+	/*
+	 * lower1=false (the second to last argument) for correct comparison lower
+	 * and upper bounds.
+	 */
+	cmpval = partition_rbound_cmp(key->partnatts,
+								  key->partsupfunc,
+								  key->partcollation,
+								  second_lower->datums, second_lower->kind,
+								  false, first_upper);
+	if ((!defaultPart && cmpval) || (defaultPart && cmpval < 0))
+	{
+		PartitionRangeDatum *datum = linitial(second_bound->lowerdatums);
+
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+				 errmsg("lower bound of partition \"%s\" conflicts with upper bound of previous partition \"%s\"",
+						second_name->relname, first_name->relname),
+				 parser_errposition(pstate, datum->location)));
+	}
+}
+
+/*
+ * get_partition_bound_spec
+ *
+ * Returns description of partition with Oid "partOid" and name "name".
+ */
+static PartitionBoundSpec *
+get_partition_bound_spec(Oid partOid, RangeVar *name)
+{
+	HeapTuple	tuple;
+	Datum		datum;
+	bool		isnull;
+	PartitionBoundSpec *boundspec = NULL;
+
+	/* Try fetching the tuple from the catcache, for speed. */
+	tuple = SearchSysCache1(RELOID, partOid);
+	if (!HeapTupleIsValid(tuple))
+		elog(ERROR, "cache lookup failed for relation \"%s\"",
+			 name->relname);
+
+	datum = SysCacheGetAttr(RELOID, tuple,
+							Anum_pg_class_relpartbound,
+							&isnull);
+	if (isnull)
+		elog(ERROR, "partition bound for relation \"%s\" is null",
+			 name->relname);
+
+	boundspec = stringToNode(TextDatumGetCString(datum));
+
+	if (!IsA(boundspec, PartitionBoundSpec))
+		elog(ERROR, "expected PartitionBoundSpec for relation \"%s\"",
+			 name->relname);
+
+	ReleaseSysCache(tuple);
+	return boundspec;
+}
+
+/*
+ * calculate_partition_bound_for_merge
+ *
+ * Calculates the bound of merged partition "spec" by using the bounds of
+ * partitions to be merged.
+ *
+ * parent:			partitioned table
+ * partNames:		names of partitions to be merged
+ * partOids:		Oids of partitions to be merged
+ * spec (out):		bounds specification of the merged partition
+ * pstate:			pointer to ParseState struct for determine error position
+ */
+void
+calculate_partition_bound_for_merge(Relation parent,
+									List *partNames,
+									List *partOids,
+									PartitionBoundSpec *spec,
+									ParseState *pstate)
+{
+	PartitionKey key = RelationGetPartitionKey(parent);
+	PartitionBoundSpec *bound;
+
+	Assert(!spec->is_default);
+
+	switch (key->strategy)
+	{
+		case PARTITION_STRATEGY_RANGE:
+			{
+				int			i;
+				PartitionRangeBound **lower_bounds;
+				int			nparts = list_length(partOids);
+				List	   *bounds = NIL;
+
+				lower_bounds = (PartitionRangeBound **)
+					palloc0(nparts * sizeof(PartitionRangeBound *));
+
+				/*
+				 * Create array of lower bounds and list of
+				 * PartitionBoundSpec.
+				 */
+				for (i = 0; i < nparts; i++)
+				{
+					bound = get_partition_bound_spec(list_nth_oid(partOids, i),
+													 (RangeVar *) list_nth(partNames, i));
+
+					lower_bounds[i] = make_one_partition_rbound(key, i, bound->lowerdatums, true);
+					bounds = lappend(bounds, bound);
+				}
+
+				/* Sort array of lower bounds. */
+				qsort_arg(lower_bounds, nparts, sizeof(PartitionRangeBound *),
+						  qsort_partition_rbound_cmp, (void *) key);
+
+				/* Ranges of partitions should not overlap. */
+				for (i = 1; i < nparts; i++)
+				{
+					int			index = lower_bounds[i]->index;
+					int			prev_index = lower_bounds[i - 1]->index;
+
+					check_two_partitions_bounds_range(parent,
+													  (RangeVar *) list_nth(partNames, prev_index),
+													  (PartitionBoundSpec *) list_nth(bounds, prev_index),
+													  (RangeVar *) list_nth(partNames, index),
+													  (PartitionBoundSpec *) list_nth(bounds, index),
+													  false, pstate);
+				}
+
+				/*
+				 * Lower bound of first partition is a lower bound of merged
+				 * partition.
+				 */
+				spec->lowerdatums =
+					((PartitionBoundSpec *) list_nth(bounds, lower_bounds[0]->index))->lowerdatums;
+
+				/*
+				 * Upper bound of last partition is a upper bound of merged
+				 * partition.
+				 */
+				spec->upperdatums =
+					((PartitionBoundSpec *) list_nth(bounds, lower_bounds[nparts - 1]->index))->upperdatums;
+
+				pfree(lower_bounds);
+				list_free(bounds);
+				break;
+			}
+
+		case PARTITION_STRATEGY_LIST:
+			{
+				ListCell   *listptr,
+						   *listptr2;
+
+				/* Consolidate bounds for all partitions in the list. */
+				forboth(listptr, partOids, listptr2, partNames)
+				{
+					RangeVar   *name = (RangeVar *) lfirst(listptr2);
+					Oid			curOid = lfirst_oid(listptr);
+
+					bound = get_partition_bound_spec(curOid, name);
+					spec->listdatums = list_concat(spec->listdatums, bound->listdatums);
+				}
+				break;
+			}
+
+		default:
+			elog(ERROR, "unexpected partition strategy: %d",
+				 (int) key->strategy);
+	}
+}
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index b89baef95d3..27c28139c84 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -933,6 +933,17 @@ typedef struct PartitionRangeDatum
 	ParseLoc	location;		/* token location, or -1 if unknown */
 } PartitionRangeDatum;
 
+/*
+ * PartitionDesc - info about single partition for ALTER TABLE SPLIT PARTITION command
+ */
+typedef struct SinglePartitionSpec
+{
+	NodeTag		type;
+
+	RangeVar   *name;			/* name of partition */
+	PartitionBoundSpec *bound;	/* FOR VALUES, if attaching */
+} SinglePartitionSpec;
+
 /*
  * PartitionCmd - info for ALTER TABLE/INDEX ATTACH/DETACH PARTITION commands
  */
@@ -941,6 +952,8 @@ typedef struct PartitionCmd
 	NodeTag		type;
 	RangeVar   *name;			/* name of partition to attach/detach */
 	PartitionBoundSpec *bound;	/* FOR VALUES, if attaching */
+	List	   *partlist;		/* list of partitions, for SPLIT PARTITION
+								 * command */
 	bool		concurrent;
 } PartitionCmd;
 
@@ -2331,6 +2344,7 @@ typedef enum AlterTableType
 	AT_AttachPartition,			/* ATTACH PARTITION */
 	AT_DetachPartition,			/* DETACH PARTITION */
 	AT_DetachPartitionFinalize, /* DETACH PARTITION FINALIZE */
+	AT_MergePartitions,			/* MERGE PARTITIONS */
 	AT_AddIdentity,				/* ADD IDENTITY */
 	AT_SetIdentity,				/* SET identity column options */
 	AT_DropIdentity,			/* DROP IDENTITY */
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 57514d064b7..e2b4700d97b 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -333,6 +333,7 @@ PG_KEYWORD("parameter", PARAMETER, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("parser", PARSER, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("partial", PARTIAL, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("partition", PARTITION, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("partitions", PARTITIONS, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("passing", PASSING, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("password", PASSWORD, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("period", PERIOD, UNRESERVED_KEYWORD, BARE_LABEL)
diff --git a/src/include/partitioning/partbounds.h b/src/include/partitioning/partbounds.h
index 3d9cc1031f7..0329d7bd848 100644
--- a/src/include/partitioning/partbounds.h
+++ b/src/include/partitioning/partbounds.h
@@ -143,4 +143,10 @@ extern int	partition_range_datum_bsearch(FmgrInfo *partsupfunc,
 extern int	partition_hash_bsearch(PartitionBoundInfo boundinfo,
 								   int modulus, int remainder);
 
+extern void calculate_partition_bound_for_merge(Relation parent,
+												List *partNames,
+												List *partOids,
+												PartitionBoundSpec *spec,
+												ParseState *pstate);
+
 #endif							/* PARTBOUNDS_H */
diff --git a/src/test/isolation/expected/partition-merge.out b/src/test/isolation/expected/partition-merge.out
new file mode 100644
index 00000000000..98446aaab5a
--- /dev/null
+++ b/src/test/isolation/expected/partition-merge.out
@@ -0,0 +1,199 @@
+Parsed test spec with 2 sessions
+
+starting permutation: s2b s2i s2c s1b s1merg s2b s2u s1c s2c s2s
+step s2b: BEGIN;
+step s2i: INSERT INTO tpart VALUES (1, 'text01');
+step s2c: COMMIT;
+step s1b: BEGIN;
+step s1merg: ALTER TABLE tpart MERGE PARTITIONS (tpart_00_10, tpart_10_20) INTO tpart_00_20;
+step s2b: BEGIN;
+step s2u: UPDATE tpart SET t = 'text01modif' where i = 1; <waiting ...>
+step s1c: COMMIT;
+step s2u: <... completed>
+step s2c: COMMIT;
+step s2s: SELECT * FROM tpart;
+ i|t          
+--+-----------
+ 5|text05     
+15|text15     
+ 1|text01modif
+25|text25     
+35|text35     
+(5 rows)
+
+
+starting permutation: s2b s2i s2c s1brr s1merg s2b s2u s1c s2c s2s
+step s2b: BEGIN;
+step s2i: INSERT INTO tpart VALUES (1, 'text01');
+step s2c: COMMIT;
+step s1brr: BEGIN ISOLATION LEVEL REPEATABLE READ;
+step s1merg: ALTER TABLE tpart MERGE PARTITIONS (tpart_00_10, tpart_10_20) INTO tpart_00_20;
+step s2b: BEGIN;
+step s2u: UPDATE tpart SET t = 'text01modif' where i = 1; <waiting ...>
+step s1c: COMMIT;
+step s2u: <... completed>
+step s2c: COMMIT;
+step s2s: SELECT * FROM tpart;
+ i|t          
+--+-----------
+ 5|text05     
+15|text15     
+ 1|text01modif
+25|text25     
+35|text35     
+(5 rows)
+
+
+starting permutation: s2b s2i s2c s1bs s1merg s2b s2u s1c s2c s2s
+step s2b: BEGIN;
+step s2i: INSERT INTO tpart VALUES (1, 'text01');
+step s2c: COMMIT;
+step s1bs: BEGIN ISOLATION LEVEL SERIALIZABLE;
+step s1merg: ALTER TABLE tpart MERGE PARTITIONS (tpart_00_10, tpart_10_20) INTO tpart_00_20;
+step s2b: BEGIN;
+step s2u: UPDATE tpart SET t = 'text01modif' where i = 1; <waiting ...>
+step s1c: COMMIT;
+step s2u: <... completed>
+step s2c: COMMIT;
+step s2s: SELECT * FROM tpart;
+ i|t          
+--+-----------
+ 5|text05     
+15|text15     
+ 1|text01modif
+25|text25     
+35|text35     
+(5 rows)
+
+
+starting permutation: s2brr s2i s2c s1b s1merg s2b s2u s1c s2c s2s
+step s2brr: BEGIN ISOLATION LEVEL REPEATABLE READ;
+step s2i: INSERT INTO tpart VALUES (1, 'text01');
+step s2c: COMMIT;
+step s1b: BEGIN;
+step s1merg: ALTER TABLE tpart MERGE PARTITIONS (tpart_00_10, tpart_10_20) INTO tpart_00_20;
+step s2b: BEGIN;
+step s2u: UPDATE tpart SET t = 'text01modif' where i = 1; <waiting ...>
+step s1c: COMMIT;
+step s2u: <... completed>
+step s2c: COMMIT;
+step s2s: SELECT * FROM tpart;
+ i|t          
+--+-----------
+ 5|text05     
+15|text15     
+ 1|text01modif
+25|text25     
+35|text35     
+(5 rows)
+
+
+starting permutation: s2brr s2i s2c s1brr s1merg s2b s2u s1c s2c s2s
+step s2brr: BEGIN ISOLATION LEVEL REPEATABLE READ;
+step s2i: INSERT INTO tpart VALUES (1, 'text01');
+step s2c: COMMIT;
+step s1brr: BEGIN ISOLATION LEVEL REPEATABLE READ;
+step s1merg: ALTER TABLE tpart MERGE PARTITIONS (tpart_00_10, tpart_10_20) INTO tpart_00_20;
+step s2b: BEGIN;
+step s2u: UPDATE tpart SET t = 'text01modif' where i = 1; <waiting ...>
+step s1c: COMMIT;
+step s2u: <... completed>
+step s2c: COMMIT;
+step s2s: SELECT * FROM tpart;
+ i|t          
+--+-----------
+ 5|text05     
+15|text15     
+ 1|text01modif
+25|text25     
+35|text35     
+(5 rows)
+
+
+starting permutation: s2brr s2i s2c s1bs s1merg s2b s2u s1c s2c s2s
+step s2brr: BEGIN ISOLATION LEVEL REPEATABLE READ;
+step s2i: INSERT INTO tpart VALUES (1, 'text01');
+step s2c: COMMIT;
+step s1bs: BEGIN ISOLATION LEVEL SERIALIZABLE;
+step s1merg: ALTER TABLE tpart MERGE PARTITIONS (tpart_00_10, tpart_10_20) INTO tpart_00_20;
+step s2b: BEGIN;
+step s2u: UPDATE tpart SET t = 'text01modif' where i = 1; <waiting ...>
+step s1c: COMMIT;
+step s2u: <... completed>
+step s2c: COMMIT;
+step s2s: SELECT * FROM tpart;
+ i|t          
+--+-----------
+ 5|text05     
+15|text15     
+ 1|text01modif
+25|text25     
+35|text35     
+(5 rows)
+
+
+starting permutation: s2bs s2i s2c s1b s1merg s2b s2u s1c s2c s2s
+step s2bs: BEGIN ISOLATION LEVEL SERIALIZABLE;
+step s2i: INSERT INTO tpart VALUES (1, 'text01');
+step s2c: COMMIT;
+step s1b: BEGIN;
+step s1merg: ALTER TABLE tpart MERGE PARTITIONS (tpart_00_10, tpart_10_20) INTO tpart_00_20;
+step s2b: BEGIN;
+step s2u: UPDATE tpart SET t = 'text01modif' where i = 1; <waiting ...>
+step s1c: COMMIT;
+step s2u: <... completed>
+step s2c: COMMIT;
+step s2s: SELECT * FROM tpart;
+ i|t          
+--+-----------
+ 5|text05     
+15|text15     
+ 1|text01modif
+25|text25     
+35|text35     
+(5 rows)
+
+
+starting permutation: s2bs s2i s2c s1brr s1merg s2b s2u s1c s2c s2s
+step s2bs: BEGIN ISOLATION LEVEL SERIALIZABLE;
+step s2i: INSERT INTO tpart VALUES (1, 'text01');
+step s2c: COMMIT;
+step s1brr: BEGIN ISOLATION LEVEL REPEATABLE READ;
+step s1merg: ALTER TABLE tpart MERGE PARTITIONS (tpart_00_10, tpart_10_20) INTO tpart_00_20;
+step s2b: BEGIN;
+step s2u: UPDATE tpart SET t = 'text01modif' where i = 1; <waiting ...>
+step s1c: COMMIT;
+step s2u: <... completed>
+step s2c: COMMIT;
+step s2s: SELECT * FROM tpart;
+ i|t          
+--+-----------
+ 5|text05     
+15|text15     
+ 1|text01modif
+25|text25     
+35|text35     
+(5 rows)
+
+
+starting permutation: s2bs s2i s2c s1bs s1merg s2b s2u s1c s2c s2s
+step s2bs: BEGIN ISOLATION LEVEL SERIALIZABLE;
+step s2i: INSERT INTO tpart VALUES (1, 'text01');
+step s2c: COMMIT;
+step s1bs: BEGIN ISOLATION LEVEL SERIALIZABLE;
+step s1merg: ALTER TABLE tpart MERGE PARTITIONS (tpart_00_10, tpart_10_20) INTO tpart_00_20;
+step s2b: BEGIN;
+step s2u: UPDATE tpart SET t = 'text01modif' where i = 1; <waiting ...>
+step s1c: COMMIT;
+step s2u: <... completed>
+step s2c: COMMIT;
+step s2s: SELECT * FROM tpart;
+ i|t          
+--+-----------
+ 5|text05     
+15|text15     
+ 1|text01modif
+25|text25     
+35|text35     
+(5 rows)
+
diff --git a/src/test/isolation/isolation_schedule b/src/test/isolation/isolation_schedule
index 188fc04f85e..8bcaa8a6254 100644
--- a/src/test/isolation/isolation_schedule
+++ b/src/test/isolation/isolation_schedule
@@ -103,6 +103,7 @@ test: partition-key-update-1
 test: partition-key-update-2
 test: partition-key-update-3
 test: partition-key-update-4
+test: partition-merge
 test: plpgsql-toast
 test: cluster-conflict
 test: cluster-conflict-partition
diff --git a/src/test/isolation/specs/partition-merge.spec b/src/test/isolation/specs/partition-merge.spec
new file mode 100644
index 00000000000..ec48732c583
--- /dev/null
+++ b/src/test/isolation/specs/partition-merge.spec
@@ -0,0 +1,54 @@
+# Verify that MERGE operation locks DML operations with partitioned table
+
+setup
+{
+  DROP TABLE IF EXISTS tpart;
+  CREATE TABLE tpart(i int, t text) partition by range(i);
+  CREATE TABLE tpart_00_10 PARTITION OF tpart FOR VALUES FROM (0) TO (10);
+  CREATE TABLE tpart_10_20 PARTITION OF tpart FOR VALUES FROM (10) TO (20);
+  CREATE TABLE tpart_20_30 PARTITION OF tpart FOR VALUES FROM (20) TO (30);
+  CREATE TABLE tpart_default PARTITION OF tpart DEFAULT;
+  INSERT INTO tpart VALUES (5, 'text05');
+  INSERT INTO tpart VALUES (15, 'text15');
+  INSERT INTO tpart VALUES (25, 'text25');
+  INSERT INTO tpart VALUES (35, 'text35');
+}
+
+teardown
+{
+  DROP TABLE tpart;
+}
+
+session s1
+step s1b	{ BEGIN; }
+step s1brr	{ BEGIN ISOLATION LEVEL REPEATABLE READ; }
+step s1bs	{ BEGIN ISOLATION LEVEL SERIALIZABLE; }
+step s1merg	{ ALTER TABLE tpart MERGE PARTITIONS (tpart_00_10, tpart_10_20) INTO tpart_00_20; }
+step s1c	{ COMMIT; }
+
+
+session s2
+step s2b	{ BEGIN; }
+step s2brr	{ BEGIN ISOLATION LEVEL REPEATABLE READ; }
+step s2bs	{ BEGIN ISOLATION LEVEL SERIALIZABLE; }
+step s2i	{ INSERT INTO tpart VALUES (1, 'text01'); }
+step s2u	{ UPDATE tpart SET t = 'text01modif' where i = 1; }
+step s2c	{ COMMIT; }
+step s2s	{ SELECT * FROM tpart; }
+
+
+# s2 inserts row into table. s1 starts MERGE PARTITIONS then
+# s2 trying to update inserted row and waits until s1 finished
+# MERGE operation.
+
+permutation s2b s2i s2c s1b s1merg s2b s2u s1c s2c s2s
+permutation s2b s2i s2c s1brr s1merg s2b s2u s1c s2c s2s
+permutation s2b s2i s2c s1bs s1merg s2b s2u s1c s2c s2s
+
+permutation s2brr s2i s2c s1b s1merg s2b s2u s1c s2c s2s
+permutation s2brr s2i s2c s1brr s1merg s2b s2u s1c s2c s2s
+permutation s2brr s2i s2c s1bs s1merg s2b s2u s1c s2c s2s
+
+permutation s2bs s2i s2c s1b s1merg s2b s2u s1c s2c s2s
+permutation s2bs s2i s2c s1brr s1merg s2b s2u s1c s2c s2s
+permutation s2bs s2i s2c s1bs s1merg s2b s2u s1c s2c s2s
diff --git a/src/test/modules/test_ddl_deparse/test_ddl_deparse.c b/src/test/modules/test_ddl_deparse/test_ddl_deparse.c
index 48563b2cf01..69920757b21 100644
--- a/src/test/modules/test_ddl_deparse/test_ddl_deparse.c
+++ b/src/test/modules/test_ddl_deparse/test_ddl_deparse.c
@@ -300,6 +300,9 @@ get_altertable_subcmdinfo(PG_FUNCTION_ARGS)
 			case AT_DetachPartitionFinalize:
 				strtype = "DETACH PARTITION ... FINALIZE";
 				break;
+			case AT_MergePartitions:
+				strtype = "MERGE PARTITIONS";
+				break;
 			case AT_AddIdentity:
 				strtype = "ADD IDENTITY";
 				break;
diff --git a/src/test/regress/expected/partition_merge.out b/src/test/regress/expected/partition_merge.out
new file mode 100644
index 00000000000..013ab659618
--- /dev/null
+++ b/src/test/regress/expected/partition_merge.out
@@ -0,0 +1,736 @@
+--
+-- PARTITIONS_MERGE
+-- Tests for "ALTER TABLE ... MERGE PARTITIONS ..." command
+--
+CREATE SCHEMA partitions_merge_schema;
+SET search_path = partitions_merge_schema, public;
+--
+-- BY RANGE partitioning
+--
+--
+-- Test for error codes
+--
+CREATE TABLE sales_range (salesman_id INT, salesman_name VARCHAR(30), sales_amount INT, sales_date DATE) PARTITION BY RANGE (sales_date);
+CREATE TABLE sales_dec2021 PARTITION OF sales_range FOR VALUES FROM ('2021-12-01') TO ('2021-12-31');
+CREATE TABLE sales_jan2022 PARTITION OF sales_range FOR VALUES FROM ('2022-01-01') TO ('2022-02-01');
+CREATE TABLE sales_feb2022 PARTITION OF sales_range FOR VALUES FROM ('2022-02-01') TO ('2022-03-01');
+CREATE TABLE sales_mar2022 PARTITION OF sales_range FOR VALUES FROM ('2022-03-01') TO ('2022-04-01');
+CREATE TABLE sales_apr2022 (salesman_id INT, salesman_name VARCHAR(30), sales_amount INT, sales_date DATE) PARTITION BY RANGE (sales_date);
+CREATE TABLE sales_apr_1 PARTITION OF sales_apr2022 FOR VALUES FROM ('2022-04-01') TO ('2022-04-15');
+CREATE TABLE sales_apr_2 PARTITION OF sales_apr2022 FOR VALUES FROM ('2022-04-15') TO ('2022-05-01');
+ALTER TABLE sales_range ATTACH PARTITION sales_apr2022 FOR VALUES FROM ('2022-04-01') TO ('2022-05-01');
+CREATE TABLE sales_others PARTITION OF sales_range DEFAULT;
+-- ERROR:  partition with name "sales_feb2022" already used
+ALTER TABLE sales_range MERGE PARTITIONS (sales_feb2022, sales_mar2022, sales_feb2022) INTO sales_feb_mar_apr2022;
+ERROR:  partition with name "sales_feb2022" already used
+LINE 1: ...e MERGE PARTITIONS (sales_feb2022, sales_mar2022, sales_feb2...
+                                                             ^
+-- ERROR:  cannot merge non-table partition "sales_apr2022"
+ALTER TABLE sales_range MERGE PARTITIONS (sales_feb2022, sales_mar2022, sales_apr2022) INTO sales_feb_mar_apr2022;
+ERROR:  cannot merge non-table partition "sales_apr2022"
+-- ERROR:  invalid partitions order, partition "sales_mar2022" can not be merged
+-- (space between sections sales_jan2022 and sales_mar2022)
+ALTER TABLE sales_range MERGE PARTITIONS (sales_jan2022, sales_mar2022) INTO sales_jan_mar2022;
+ERROR:  lower bound of partition "sales_mar2022" conflicts with upper bound of previous partition "sales_jan2022"
+-- ERROR:  invalid partitions order, partition "sales_jan2022" can not be merged
+-- (space between sections sales_dec2021 and sales_jan2022)
+ALTER TABLE sales_range MERGE PARTITIONS (sales_dec2021, sales_jan2022, sales_feb2022) INTO sales_dec_jan_feb2022;
+ERROR:  lower bound of partition "sales_jan2022" conflicts with upper bound of previous partition "sales_dec2021"
+-- NO ERROR: test for custom partitions order
+ALTER TABLE sales_range MERGE PARTITIONS (sales_feb2022, sales_mar2022, sales_jan2022) INTO sales_jan_feb_mar2022;
+SELECT c.oid::pg_catalog.regclass, c.relkind, inhdetachpending, pg_catalog.pg_get_expr(c.relpartbound, c.oid)
+  FROM pg_catalog.pg_class c, pg_catalog.pg_inherits i
+  WHERE c.oid = i.inhrelid AND i.inhparent = 'sales_range'::regclass
+  ORDER BY pg_catalog.pg_get_expr(c.relpartbound, c.oid) = 'DEFAULT', c.oid::pg_catalog.regclass::pg_catalog.text;
+          oid          | relkind | inhdetachpending |                   pg_get_expr                    
+-----------------------+---------+------------------+--------------------------------------------------
+ sales_apr2022         | p       | f                | FOR VALUES FROM ('04-01-2022') TO ('05-01-2022')
+ sales_dec2021         | r       | f                | FOR VALUES FROM ('12-01-2021') TO ('12-31-2021')
+ sales_jan_feb_mar2022 | r       | f                | FOR VALUES FROM ('01-01-2022') TO ('04-01-2022')
+ sales_others          | r       | f                | DEFAULT
+(4 rows)
+
+DROP TABLE sales_range;
+--
+-- Add rows into partitioned table then merge partitions
+--
+CREATE TABLE sales_range (salesman_id INT, salesman_name VARCHAR(30), sales_amount INT, sales_date DATE) PARTITION BY RANGE (sales_date);
+CREATE TABLE sales_jan2022 PARTITION OF sales_range FOR VALUES FROM ('2022-01-01') TO ('2022-02-01');
+CREATE TABLE sales_feb2022 PARTITION OF sales_range FOR VALUES FROM ('2022-02-01') TO ('2022-03-01');
+CREATE TABLE sales_mar2022 PARTITION OF sales_range FOR VALUES FROM ('2022-03-01') TO ('2022-04-01');
+CREATE TABLE sales_apr2022 PARTITION OF sales_range FOR VALUES FROM ('2022-04-01') TO ('2022-05-01');
+CREATE TABLE sales_others PARTITION OF sales_range DEFAULT;
+CREATE INDEX sales_range_sales_date_idx ON sales_range USING btree (sales_date);
+INSERT INTO sales_range VALUES (1,  'May',      1000, '2022-01-31');
+INSERT INTO sales_range VALUES (2,  'Smirnoff', 500,  '2022-02-10');
+INSERT INTO sales_range VALUES (3,  'Ford',     2000, '2022-04-30');
+INSERT INTO sales_range VALUES (4,  'Ivanov',   750,  '2022-04-13');
+INSERT INTO sales_range VALUES (5,  'Deev',     250,  '2022-04-07');
+INSERT INTO sales_range VALUES (6,  'Poirot',   150,  '2022-02-11');
+INSERT INTO sales_range VALUES (7,  'Li',       175,  '2022-03-08');
+INSERT INTO sales_range VALUES (8,  'Ericsson', 185,  '2022-02-23');
+INSERT INTO sales_range VALUES (9,  'Muller',   250,  '2022-03-11');
+INSERT INTO sales_range VALUES (10, 'Halder',   350,  '2022-01-28');
+INSERT INTO sales_range VALUES (11, 'Trump',    380,  '2022-04-06');
+INSERT INTO sales_range VALUES (12, 'Plato',    350,  '2022-03-19');
+INSERT INTO sales_range VALUES (13, 'Gandi',    377,  '2022-01-09');
+INSERT INTO sales_range VALUES (14, 'Smith',    510,  '2022-05-04');
+SELECT pg_catalog.pg_get_partkeydef('sales_range'::regclass);
+ pg_get_partkeydef  
+--------------------
+ RANGE (sales_date)
+(1 row)
+
+-- show partitions with conditions:
+SELECT c.oid::pg_catalog.regclass, c.relkind, inhdetachpending, pg_catalog.pg_get_expr(c.relpartbound, c.oid)
+  FROM pg_catalog.pg_class c, pg_catalog.pg_inherits i
+  WHERE c.oid = i.inhrelid AND i.inhparent = 'sales_range'::regclass
+  ORDER BY pg_catalog.pg_get_expr(c.relpartbound, c.oid) = 'DEFAULT', c.oid::pg_catalog.regclass::pg_catalog.text;
+      oid      | relkind | inhdetachpending |                   pg_get_expr                    
+---------------+---------+------------------+--------------------------------------------------
+ sales_apr2022 | r       | f                | FOR VALUES FROM ('04-01-2022') TO ('05-01-2022')
+ sales_feb2022 | r       | f                | FOR VALUES FROM ('02-01-2022') TO ('03-01-2022')
+ sales_jan2022 | r       | f                | FOR VALUES FROM ('01-01-2022') TO ('02-01-2022')
+ sales_mar2022 | r       | f                | FOR VALUES FROM ('03-01-2022') TO ('04-01-2022')
+ sales_others  | r       | f                | DEFAULT
+(5 rows)
+
+ALTER TABLE sales_range MERGE PARTITIONS (sales_feb2022, sales_mar2022, sales_apr2022) INTO sales_feb_mar_apr2022;
+-- show partitions with conditions:
+SELECT c.oid::pg_catalog.regclass, c.relkind, inhdetachpending, pg_catalog.pg_get_expr(c.relpartbound, c.oid)
+  FROM pg_catalog.pg_class c, pg_catalog.pg_inherits i
+  WHERE c.oid = i.inhrelid AND i.inhparent = 'sales_range'::regclass
+  ORDER BY pg_catalog.pg_get_expr(c.relpartbound, c.oid) = 'DEFAULT', c.oid::pg_catalog.regclass::pg_catalog.text;
+          oid          | relkind | inhdetachpending |                   pg_get_expr                    
+-----------------------+---------+------------------+--------------------------------------------------
+ sales_feb_mar_apr2022 | r       | f                | FOR VALUES FROM ('02-01-2022') TO ('05-01-2022')
+ sales_jan2022         | r       | f                | FOR VALUES FROM ('01-01-2022') TO ('02-01-2022')
+ sales_others          | r       | f                | DEFAULT
+(3 rows)
+
+SELECT * FROM pg_indexes WHERE tablename = 'sales_feb_mar_apr2022' and schemaname = 'partitions_merge_schema';
+       schemaname        |       tablename       |              indexname               | tablespace |                                                          indexdef                                                           
+-------------------------+-----------------------+--------------------------------------+------------+-----------------------------------------------------------------------------------------------------------------------------
+ partitions_merge_schema | sales_feb_mar_apr2022 | sales_feb_mar_apr2022_sales_date_idx |            | CREATE INDEX sales_feb_mar_apr2022_sales_date_idx ON partitions_merge_schema.sales_feb_mar_apr2022 USING btree (sales_date)
+(1 row)
+
+SELECT * FROM sales_range;
+ salesman_id | salesman_name | sales_amount | sales_date 
+-------------+---------------+--------------+------------
+           1 | May           |         1000 | 01-31-2022
+          10 | Halder        |          350 | 01-28-2022
+          13 | Gandi         |          377 | 01-09-2022
+           2 | Smirnoff      |          500 | 02-10-2022
+           6 | Poirot        |          150 | 02-11-2022
+           8 | Ericsson      |          185 | 02-23-2022
+           7 | Li            |          175 | 03-08-2022
+           9 | Muller        |          250 | 03-11-2022
+          12 | Plato         |          350 | 03-19-2022
+           3 | Ford          |         2000 | 04-30-2022
+           4 | Ivanov        |          750 | 04-13-2022
+           5 | Deev          |          250 | 04-07-2022
+          11 | Trump         |          380 | 04-06-2022
+          14 | Smith         |          510 | 05-04-2022
+(14 rows)
+
+SELECT * FROM sales_jan2022;
+ salesman_id | salesman_name | sales_amount | sales_date 
+-------------+---------------+--------------+------------
+           1 | May           |         1000 | 01-31-2022
+          10 | Halder        |          350 | 01-28-2022
+          13 | Gandi         |          377 | 01-09-2022
+(3 rows)
+
+SELECT * FROM sales_feb_mar_apr2022;
+ salesman_id | salesman_name | sales_amount | sales_date 
+-------------+---------------+--------------+------------
+           2 | Smirnoff      |          500 | 02-10-2022
+           6 | Poirot        |          150 | 02-11-2022
+           8 | Ericsson      |          185 | 02-23-2022
+           7 | Li            |          175 | 03-08-2022
+           9 | Muller        |          250 | 03-11-2022
+          12 | Plato         |          350 | 03-19-2022
+           3 | Ford          |         2000 | 04-30-2022
+           4 | Ivanov        |          750 | 04-13-2022
+           5 | Deev          |          250 | 04-07-2022
+          11 | Trump         |          380 | 04-06-2022
+(10 rows)
+
+SELECT * FROM sales_others;
+ salesman_id | salesman_name | sales_amount | sales_date 
+-------------+---------------+--------------+------------
+          14 | Smith         |          510 | 05-04-2022
+(1 row)
+
+-- Use indexscan for test indexes
+SET enable_indexscan = ON;
+SET enable_seqscan = OFF;
+SELECT * FROM sales_feb_mar_apr2022 where sales_date > '2022-01-01';
+ salesman_id | salesman_name | sales_amount | sales_date 
+-------------+---------------+--------------+------------
+           2 | Smirnoff      |          500 | 02-10-2022
+           6 | Poirot        |          150 | 02-11-2022
+           8 | Ericsson      |          185 | 02-23-2022
+           7 | Li            |          175 | 03-08-2022
+           9 | Muller        |          250 | 03-11-2022
+          12 | Plato         |          350 | 03-19-2022
+          11 | Trump         |          380 | 04-06-2022
+           5 | Deev          |          250 | 04-07-2022
+           4 | Ivanov        |          750 | 04-13-2022
+           3 | Ford          |         2000 | 04-30-2022
+(10 rows)
+
+SET enable_indexscan = ON;
+SET enable_seqscan = ON;
+DROP TABLE sales_range;
+--
+-- Merge some partitions into DEFAULT partition
+--
+CREATE TABLE sales_range (salesman_id INT, salesman_name VARCHAR(30), sales_amount INT, sales_date DATE) PARTITION BY RANGE (sales_date);
+CREATE TABLE sales_jan2022 PARTITION OF sales_range FOR VALUES FROM ('2022-01-01') TO ('2022-02-01');
+CREATE TABLE sales_feb2022 PARTITION OF sales_range FOR VALUES FROM ('2022-02-01') TO ('2022-03-01');
+CREATE TABLE sales_mar2022 PARTITION OF sales_range FOR VALUES FROM ('2022-03-01') TO ('2022-04-01');
+CREATE TABLE sales_apr2022 PARTITION OF sales_range FOR VALUES FROM ('2022-04-01') TO ('2022-05-01');
+CREATE TABLE sales_others PARTITION OF sales_range DEFAULT;
+CREATE INDEX sales_range_sales_date_idx ON sales_range USING btree (sales_date);
+INSERT INTO sales_range VALUES (1,  'May',      1000, '2022-01-31');
+INSERT INTO sales_range VALUES (2,  'Smirnoff', 500,  '2022-02-10');
+INSERT INTO sales_range VALUES (3,  'Ford',     2000, '2022-04-30');
+INSERT INTO sales_range VALUES (4,  'Ivanov',   750,  '2022-04-13');
+INSERT INTO sales_range VALUES (5,  'Deev',     250,  '2022-04-07');
+INSERT INTO sales_range VALUES (6,  'Poirot',   150,  '2022-02-11');
+INSERT INTO sales_range VALUES (7,  'Li',       175,  '2022-03-08');
+INSERT INTO sales_range VALUES (8,  'Ericsson', 185,  '2022-02-23');
+INSERT INTO sales_range VALUES (9,  'Muller',   250,  '2022-03-11');
+INSERT INTO sales_range VALUES (10, 'Halder',   350,  '2022-01-28');
+INSERT INTO sales_range VALUES (11, 'Trump',    380,  '2022-04-06');
+INSERT INTO sales_range VALUES (12, 'Plato',    350,  '2022-03-19');
+INSERT INTO sales_range VALUES (13, 'Gandi',    377,  '2022-01-09');
+INSERT INTO sales_range VALUES (14, 'Smith',    510,  '2022-05-04');
+-- Merge partitions (include DEFAULT partition) into partition with the same
+-- name
+ALTER TABLE sales_range MERGE PARTITIONS (sales_jan2022, sales_mar2022, sales_others) INTO sales_others;
+select * from sales_others;
+ salesman_id | salesman_name | sales_amount | sales_date 
+-------------+---------------+--------------+------------
+           1 | May           |         1000 | 01-31-2022
+          10 | Halder        |          350 | 01-28-2022
+          13 | Gandi         |          377 | 01-09-2022
+           7 | Li            |          175 | 03-08-2022
+           9 | Muller        |          250 | 03-11-2022
+          12 | Plato         |          350 | 03-19-2022
+          14 | Smith         |          510 | 05-04-2022
+(7 rows)
+
+-- show partitions with conditions:
+SELECT c.oid::pg_catalog.regclass, c.relkind, inhdetachpending, pg_catalog.pg_get_expr(c.relpartbound, c.oid)
+  FROM pg_catalog.pg_class c, pg_catalog.pg_inherits i
+  WHERE c.oid = i.inhrelid AND i.inhparent = 'sales_range'::regclass
+  ORDER BY pg_catalog.pg_get_expr(c.relpartbound, c.oid) = 'DEFAULT', c.oid::pg_catalog.regclass::pg_catalog.text;
+      oid      | relkind | inhdetachpending |                   pg_get_expr                    
+---------------+---------+------------------+--------------------------------------------------
+ sales_apr2022 | r       | f                | FOR VALUES FROM ('04-01-2022') TO ('05-01-2022')
+ sales_feb2022 | r       | f                | FOR VALUES FROM ('02-01-2022') TO ('03-01-2022')
+ sales_others  | r       | f                | DEFAULT
+(3 rows)
+
+DROP TABLE sales_range;
+--
+-- Test for:
+--   * composite partition key;
+--   * GENERATED column;
+--   * column with DEFAULT value.
+--
+CREATE TABLE sales_date (salesman_name VARCHAR(30), sales_year INT, sales_month INT, sales_day INT,
+  sales_date VARCHAR(10) GENERATED ALWAYS AS
+    (LPAD(sales_year::text, 4, '0') || '.' || LPAD(sales_month::text, 2, '0') || '.' || LPAD(sales_day::text, 2, '0')) STORED,
+  sales_department VARCHAR(30) DEFAULT 'Sales department')
+  PARTITION BY RANGE (sales_year, sales_month, sales_day);
+CREATE TABLE sales_dec2022 PARTITION OF sales_date FOR VALUES FROM (2021, 12, 1) TO (2022, 1, 1);
+CREATE TABLE sales_jan2022 PARTITION OF sales_date FOR VALUES FROM (2022, 1, 1) TO (2022, 2, 1);
+CREATE TABLE sales_feb2022 PARTITION OF sales_date FOR VALUES FROM (2022, 2, 1) TO (2022, 3, 1);
+CREATE TABLE sales_other PARTITION OF sales_date FOR VALUES FROM (2022, 3, 1) TO (MAXVALUE, MAXVALUE, MAXVALUE);
+INSERT INTO sales_date(salesman_name, sales_year, sales_month, sales_day) VALUES ('Manager1', 2021, 12, 7);
+INSERT INTO sales_date(salesman_name, sales_year, sales_month, sales_day) VALUES ('Manager2', 2021, 12, 8);
+INSERT INTO sales_date(salesman_name, sales_year, sales_month, sales_day) VALUES ('Manager3', 2022, 1, 1);
+INSERT INTO sales_date(salesman_name, sales_year, sales_month, sales_day) VALUES ('Manager1', 2022, 2, 4);
+INSERT INTO sales_date(salesman_name, sales_year, sales_month, sales_day) VALUES ('Manager2', 2022, 1, 2);
+INSERT INTO sales_date(salesman_name, sales_year, sales_month, sales_day) VALUES ('Manager3', 2022, 2, 1);
+INSERT INTO sales_date(salesman_name, sales_year, sales_month, sales_day) VALUES ('Manager1', 2022, 3, 3);
+INSERT INTO sales_date(salesman_name, sales_year, sales_month, sales_day) VALUES ('Manager2', 2022, 3, 4);
+INSERT INTO sales_date(salesman_name, sales_year, sales_month, sales_day) VALUES ('Manager3', 2022, 5, 1);
+SELECT * FROM sales_date;
+ salesman_name | sales_year | sales_month | sales_day | sales_date | sales_department 
+---------------+------------+-------------+-----------+------------+------------------
+ Manager1      |       2021 |          12 |         7 | 2021.12.07 | Sales department
+ Manager2      |       2021 |          12 |         8 | 2021.12.08 | Sales department
+ Manager3      |       2022 |           1 |         1 | 2022.01.01 | Sales department
+ Manager2      |       2022 |           1 |         2 | 2022.01.02 | Sales department
+ Manager1      |       2022 |           2 |         4 | 2022.02.04 | Sales department
+ Manager3      |       2022 |           2 |         1 | 2022.02.01 | Sales department
+ Manager1      |       2022 |           3 |         3 | 2022.03.03 | Sales department
+ Manager2      |       2022 |           3 |         4 | 2022.03.04 | Sales department
+ Manager3      |       2022 |           5 |         1 | 2022.05.01 | Sales department
+(9 rows)
+
+SELECT * FROM sales_dec2022;
+ salesman_name | sales_year | sales_month | sales_day | sales_date | sales_department 
+---------------+------------+-------------+-----------+------------+------------------
+ Manager1      |       2021 |          12 |         7 | 2021.12.07 | Sales department
+ Manager2      |       2021 |          12 |         8 | 2021.12.08 | Sales department
+(2 rows)
+
+SELECT * FROM sales_jan2022;
+ salesman_name | sales_year | sales_month | sales_day | sales_date | sales_department 
+---------------+------------+-------------+-----------+------------+------------------
+ Manager3      |       2022 |           1 |         1 | 2022.01.01 | Sales department
+ Manager2      |       2022 |           1 |         2 | 2022.01.02 | Sales department
+(2 rows)
+
+SELECT * FROM sales_feb2022;
+ salesman_name | sales_year | sales_month | sales_day | sales_date | sales_department 
+---------------+------------+-------------+-----------+------------+------------------
+ Manager1      |       2022 |           2 |         4 | 2022.02.04 | Sales department
+ Manager3      |       2022 |           2 |         1 | 2022.02.01 | Sales department
+(2 rows)
+
+SELECT * FROM sales_other;
+ salesman_name | sales_year | sales_month | sales_day | sales_date | sales_department 
+---------------+------------+-------------+-----------+------------+------------------
+ Manager1      |       2022 |           3 |         3 | 2022.03.03 | Sales department
+ Manager2      |       2022 |           3 |         4 | 2022.03.04 | Sales department
+ Manager3      |       2022 |           5 |         1 | 2022.05.01 | Sales department
+(3 rows)
+
+ALTER TABLE sales_date MERGE PARTITIONS (sales_jan2022, sales_feb2022) INTO sales_jan_feb2022;
+INSERT INTO sales_date(salesman_name, sales_year, sales_month, sales_day) VALUES ('Manager1', 2022, 1, 10);
+INSERT INTO sales_date(salesman_name, sales_year, sales_month, sales_day) VALUES ('Manager2', 2022, 2, 10);
+SELECT * FROM sales_date;
+ salesman_name | sales_year | sales_month | sales_day | sales_date | sales_department 
+---------------+------------+-------------+-----------+------------+------------------
+ Manager1      |       2021 |          12 |         7 | 2021.12.07 | Sales department
+ Manager2      |       2021 |          12 |         8 | 2021.12.08 | Sales department
+ Manager3      |       2022 |           1 |         1 | 2022.01.01 | Sales department
+ Manager2      |       2022 |           1 |         2 | 2022.01.02 | Sales department
+ Manager1      |       2022 |           2 |         4 | 2022.02.04 | Sales department
+ Manager3      |       2022 |           2 |         1 | 2022.02.01 | Sales department
+ Manager1      |       2022 |           1 |        10 | 2022.01.10 | Sales department
+ Manager2      |       2022 |           2 |        10 | 2022.02.10 | Sales department
+ Manager1      |       2022 |           3 |         3 | 2022.03.03 | Sales department
+ Manager2      |       2022 |           3 |         4 | 2022.03.04 | Sales department
+ Manager3      |       2022 |           5 |         1 | 2022.05.01 | Sales department
+(11 rows)
+
+SELECT * FROM sales_dec2022;
+ salesman_name | sales_year | sales_month | sales_day | sales_date | sales_department 
+---------------+------------+-------------+-----------+------------+------------------
+ Manager1      |       2021 |          12 |         7 | 2021.12.07 | Sales department
+ Manager2      |       2021 |          12 |         8 | 2021.12.08 | Sales department
+(2 rows)
+
+SELECT * FROM sales_jan_feb2022;
+ salesman_name | sales_year | sales_month | sales_day | sales_date | sales_department 
+---------------+------------+-------------+-----------+------------+------------------
+ Manager3      |       2022 |           1 |         1 | 2022.01.01 | Sales department
+ Manager2      |       2022 |           1 |         2 | 2022.01.02 | Sales department
+ Manager1      |       2022 |           2 |         4 | 2022.02.04 | Sales department
+ Manager3      |       2022 |           2 |         1 | 2022.02.01 | Sales department
+ Manager1      |       2022 |           1 |        10 | 2022.01.10 | Sales department
+ Manager2      |       2022 |           2 |        10 | 2022.02.10 | Sales department
+(6 rows)
+
+SELECT * FROM sales_other;
+ salesman_name | sales_year | sales_month | sales_day | sales_date | sales_department 
+---------------+------------+-------------+-----------+------------+------------------
+ Manager1      |       2022 |           3 |         3 | 2022.03.03 | Sales department
+ Manager2      |       2022 |           3 |         4 | 2022.03.04 | Sales department
+ Manager3      |       2022 |           5 |         1 | 2022.05.01 | Sales department
+(3 rows)
+
+DROP TABLE sales_date;
+--
+-- Test: merge partitions of partitioned table with triggers
+--
+CREATE TABLE salesmans(salesman_id INT PRIMARY KEY, salesman_name VARCHAR(30)) PARTITION BY RANGE (salesman_id);
+CREATE TABLE salesmans01_10 PARTITION OF salesmans FOR VALUES FROM (1) TO (10);
+CREATE TABLE salesmans10_20 PARTITION OF salesmans FOR VALUES FROM (10) TO (20);
+CREATE TABLE salesmans20_30 PARTITION OF salesmans FOR VALUES FROM (20) TO (30);
+CREATE TABLE salesmans30_40 PARTITION OF salesmans FOR VALUES FROM (30) TO (40);
+INSERT INTO salesmans VALUES (1,  'Poirot');
+CREATE OR REPLACE FUNCTION after_insert_row_trigger() RETURNS trigger LANGUAGE 'plpgsql' AS $BODY$
+BEGIN
+	RAISE NOTICE 'trigger(%) called: action = %, when = %, level = %', TG_ARGV[0], TG_OP, TG_WHEN, TG_LEVEL;
+    RETURN NULL;
+END;
+$BODY$;
+CREATE TRIGGER salesmans_after_insert_statement_trigger
+    AFTER INSERT
+    ON salesmans
+    FOR EACH STATEMENT
+    EXECUTE PROCEDURE after_insert_row_trigger('salesmans');
+CREATE TRIGGER salesmans_after_insert_row_trigger
+    AFTER INSERT
+    ON salesmans
+    FOR EACH ROW
+    EXECUTE PROCEDURE after_insert_row_trigger('salesmans');
+-- 2 triggers should fire here (row + statement):
+INSERT INTO salesmans VALUES (10, 'May');
+NOTICE:  trigger(salesmans) called: action = INSERT, when = AFTER, level = ROW
+NOTICE:  trigger(salesmans) called: action = INSERT, when = AFTER, level = STATEMENT
+-- 1 trigger should fire here (row):
+INSERT INTO salesmans10_20 VALUES (19, 'Ivanov');
+NOTICE:  trigger(salesmans) called: action = INSERT, when = AFTER, level = ROW
+ALTER TABLE salesmans MERGE PARTITIONS (salesmans10_20, salesmans20_30, salesmans30_40) INTO salesmans10_40;
+-- 2 triggers should fire here (row + statement):
+INSERT INTO salesmans VALUES (20, 'Smirnoff');
+NOTICE:  trigger(salesmans) called: action = INSERT, when = AFTER, level = ROW
+NOTICE:  trigger(salesmans) called: action = INSERT, when = AFTER, level = STATEMENT
+-- 1 trigger should fire here (row):
+INSERT INTO salesmans10_40 VALUES (30, 'Ford');
+NOTICE:  trigger(salesmans) called: action = INSERT, when = AFTER, level = ROW
+SELECT * FROM salesmans01_10;
+ salesman_id | salesman_name 
+-------------+---------------
+           1 | Poirot
+(1 row)
+
+SELECT * FROM salesmans10_40;
+ salesman_id | salesman_name 
+-------------+---------------
+          10 | May
+          19 | Ivanov
+          20 | Smirnoff
+          30 | Ford
+(4 rows)
+
+DROP TABLE salesmans;
+DROP FUNCTION after_insert_row_trigger();
+--
+-- Test: merge partitions with deleted columns
+--
+CREATE TABLE salesmans(salesman_id INT PRIMARY KEY, salesman_name VARCHAR(30)) PARTITION BY RANGE (salesman_id);
+CREATE TABLE salesmans01_10 PARTITION OF salesmans FOR VALUES FROM (1) TO (10);
+-- Create partitions with some deleted columns:
+CREATE TABLE salesmans10_20(d1 VARCHAR(30), salesman_id INT PRIMARY KEY, salesman_name VARCHAR(30));
+CREATE TABLE salesmans20_30(salesman_id INT PRIMARY KEY, d2 INT,  salesman_name VARCHAR(30));
+CREATE TABLE salesmans30_40(salesman_id INT PRIMARY KEY, d3 DATE, salesman_name VARCHAR(30));
+INSERT INTO salesmans10_20 VALUES ('dummy value 1', 19, 'Ivanov');
+INSERT INTO salesmans20_30 VALUES (20, 101, 'Smirnoff');
+INSERT INTO salesmans30_40 VALUES (31, now(), 'Popov');
+ALTER TABLE salesmans10_20 DROP COLUMN d1;
+ALTER TABLE salesmans20_30 DROP COLUMN d2;
+ALTER TABLE salesmans30_40 DROP COLUMN d3;
+ALTER TABLE salesmans ATTACH PARTITION salesmans10_20 FOR VALUES FROM (10) TO (20);
+ALTER TABLE salesmans ATTACH PARTITION salesmans20_30 FOR VALUES FROM (20) TO (30);
+ALTER TABLE salesmans ATTACH PARTITION salesmans30_40 FOR VALUES FROM (30) TO (40);
+INSERT INTO salesmans VALUES (1, 'Poirot');
+INSERT INTO salesmans VALUES (10, 'May');
+INSERT INTO salesmans VALUES (30, 'Ford');
+ALTER TABLE salesmans MERGE PARTITIONS (salesmans10_20, salesmans20_30, salesmans30_40) INTO salesmans10_40;
+select * from salesmans;
+ salesman_id | salesman_name 
+-------------+---------------
+           1 | Poirot
+          19 | Ivanov
+          10 | May
+          20 | Smirnoff
+          31 | Popov
+          30 | Ford
+(6 rows)
+
+select * from salesmans01_10;
+ salesman_id | salesman_name 
+-------------+---------------
+           1 | Poirot
+(1 row)
+
+select * from salesmans10_40;
+ salesman_id | salesman_name 
+-------------+---------------
+          19 | Ivanov
+          10 | May
+          20 | Smirnoff
+          31 | Popov
+          30 | Ford
+(5 rows)
+
+DROP TABLE salesmans;
+--
+-- Test: merge sub-partitions
+--
+CREATE TABLE sales_range (salesman_id INT, salesman_name VARCHAR(30), sales_amount INT, sales_date DATE) PARTITION BY RANGE (sales_date);
+CREATE TABLE sales_jan2022 PARTITION OF sales_range FOR VALUES FROM ('2022-01-01') TO ('2022-02-01');
+CREATE TABLE sales_feb2022 PARTITION OF sales_range FOR VALUES FROM ('2022-02-01') TO ('2022-03-01');
+CREATE TABLE sales_mar2022 PARTITION OF sales_range FOR VALUES FROM ('2022-03-01') TO ('2022-04-01');
+CREATE TABLE sales_apr2022 (salesman_id INT, salesman_name VARCHAR(30), sales_amount INT, sales_date DATE) PARTITION BY RANGE (sales_date);
+CREATE TABLE sales_apr2022_01_10 PARTITION OF sales_apr2022 FOR VALUES FROM ('2022-04-01') TO ('2022-04-10');
+CREATE TABLE sales_apr2022_10_20 PARTITION OF sales_apr2022 FOR VALUES FROM ('2022-04-10') TO ('2022-04-20');
+CREATE TABLE sales_apr2022_20_30 PARTITION OF sales_apr2022 FOR VALUES FROM ('2022-04-20') TO ('2022-05-01');
+ALTER TABLE sales_range ATTACH PARTITION sales_apr2022 FOR VALUES FROM ('2022-04-01') TO ('2022-05-01');
+CREATE TABLE sales_others PARTITION OF sales_range DEFAULT;
+CREATE INDEX sales_range_sales_date_idx ON sales_range USING btree (sales_date);
+INSERT INTO sales_range VALUES (1,  'May',      1000, '2022-01-31');
+INSERT INTO sales_range VALUES (2,  'Smirnoff', 500,  '2022-02-10');
+INSERT INTO sales_range VALUES (3,  'Ford',     2000, '2022-04-30');
+INSERT INTO sales_range VALUES (4,  'Ivanov',   750,  '2022-04-13');
+INSERT INTO sales_range VALUES (5,  'Deev',     250,  '2022-04-07');
+INSERT INTO sales_range VALUES (6,  'Poirot',   150,  '2022-02-11');
+INSERT INTO sales_range VALUES (7,  'Li',       175,  '2022-03-08');
+INSERT INTO sales_range VALUES (8,  'Ericsson', 185,  '2022-02-23');
+INSERT INTO sales_range VALUES (9,  'Muller',   250,  '2022-03-11');
+INSERT INTO sales_range VALUES (10, 'Halder',   350,  '2022-01-28');
+INSERT INTO sales_range VALUES (11, 'Trump',    380,  '2022-04-06');
+INSERT INTO sales_range VALUES (12, 'Plato',    350,  '2022-03-19');
+INSERT INTO sales_range VALUES (13, 'Gandi',    377,  '2022-01-09');
+INSERT INTO sales_range VALUES (14, 'Smith',    510,  '2022-05-04');
+SELECT * FROM sales_range;
+ salesman_id | salesman_name | sales_amount | sales_date 
+-------------+---------------+--------------+------------
+           1 | May           |         1000 | 01-31-2022
+          10 | Halder        |          350 | 01-28-2022
+          13 | Gandi         |          377 | 01-09-2022
+           2 | Smirnoff      |          500 | 02-10-2022
+           6 | Poirot        |          150 | 02-11-2022
+           8 | Ericsson      |          185 | 02-23-2022
+           7 | Li            |          175 | 03-08-2022
+           9 | Muller        |          250 | 03-11-2022
+          12 | Plato         |          350 | 03-19-2022
+           5 | Deev          |          250 | 04-07-2022
+          11 | Trump         |          380 | 04-06-2022
+           4 | Ivanov        |          750 | 04-13-2022
+           3 | Ford          |         2000 | 04-30-2022
+          14 | Smith         |          510 | 05-04-2022
+(14 rows)
+
+SELECT * FROM sales_apr2022;
+ salesman_id | salesman_name | sales_amount | sales_date 
+-------------+---------------+--------------+------------
+           5 | Deev          |          250 | 04-07-2022
+          11 | Trump         |          380 | 04-06-2022
+           4 | Ivanov        |          750 | 04-13-2022
+           3 | Ford          |         2000 | 04-30-2022
+(4 rows)
+
+SELECT * FROM sales_apr2022_01_10;
+ salesman_id | salesman_name | sales_amount | sales_date 
+-------------+---------------+--------------+------------
+           5 | Deev          |          250 | 04-07-2022
+          11 | Trump         |          380 | 04-06-2022
+(2 rows)
+
+SELECT * FROM sales_apr2022_10_20;
+ salesman_id | salesman_name | sales_amount | sales_date 
+-------------+---------------+--------------+------------
+           4 | Ivanov        |          750 | 04-13-2022
+(1 row)
+
+SELECT * FROM sales_apr2022_20_30;
+ salesman_id | salesman_name | sales_amount | sales_date 
+-------------+---------------+--------------+------------
+           3 | Ford          |         2000 | 04-30-2022
+(1 row)
+
+ALTER TABLE sales_apr2022 MERGE PARTITIONS (sales_apr2022_01_10, sales_apr2022_10_20, sales_apr2022_20_30) INTO sales_apr_all;
+SELECT * FROM sales_range;
+ salesman_id | salesman_name | sales_amount | sales_date 
+-------------+---------------+--------------+------------
+           1 | May           |         1000 | 01-31-2022
+          10 | Halder        |          350 | 01-28-2022
+          13 | Gandi         |          377 | 01-09-2022
+           2 | Smirnoff      |          500 | 02-10-2022
+           6 | Poirot        |          150 | 02-11-2022
+           8 | Ericsson      |          185 | 02-23-2022
+           7 | Li            |          175 | 03-08-2022
+           9 | Muller        |          250 | 03-11-2022
+          12 | Plato         |          350 | 03-19-2022
+           5 | Deev          |          250 | 04-07-2022
+          11 | Trump         |          380 | 04-06-2022
+           4 | Ivanov        |          750 | 04-13-2022
+           3 | Ford          |         2000 | 04-30-2022
+          14 | Smith         |          510 | 05-04-2022
+(14 rows)
+
+SELECT * FROM sales_apr2022;
+ salesman_id | salesman_name | sales_amount | sales_date 
+-------------+---------------+--------------+------------
+           5 | Deev          |          250 | 04-07-2022
+          11 | Trump         |          380 | 04-06-2022
+           4 | Ivanov        |          750 | 04-13-2022
+           3 | Ford          |         2000 | 04-30-2022
+(4 rows)
+
+SELECT * FROM sales_apr_all;
+ salesman_id | salesman_name | sales_amount | sales_date 
+-------------+---------------+--------------+------------
+           5 | Deev          |          250 | 04-07-2022
+          11 | Trump         |          380 | 04-06-2022
+           4 | Ivanov        |          750 | 04-13-2022
+           3 | Ford          |         2000 | 04-30-2022
+(4 rows)
+
+DROP TABLE sales_range;
+--
+-- BY LIST partitioning
+--
+--
+-- Test: specific errors for BY LIST partitioning
+--
+CREATE TABLE sales_list
+(salesman_id INT GENERATED ALWAYS AS IDENTITY,
+ salesman_name VARCHAR(30),
+ sales_state VARCHAR(20),
+ sales_amount INT,
+ sales_date DATE)
+PARTITION BY LIST (sales_state);
+CREATE TABLE sales_nord PARTITION OF sales_list FOR VALUES IN ('Murmansk', 'St. Petersburg', 'Ukhta');
+CREATE TABLE sales_west PARTITION OF sales_list FOR VALUES IN ('Voronezh', 'Smolensk', 'Bryansk');
+CREATE TABLE sales_east PARTITION OF sales_list FOR VALUES IN ('Magadan', 'Khabarovsk', 'Vladivostok');
+CREATE TABLE sales_central PARTITION OF sales_list FOR VALUES IN ('Moscow', 'Kazan', 'Volgograd');
+CREATE TABLE sales_others PARTITION OF sales_list DEFAULT;
+CREATE TABLE sales_list2 (LIKE sales_list) PARTITION BY LIST (sales_state);
+CREATE TABLE sales_nord2 PARTITION OF sales_list2 FOR VALUES IN ('Murmansk', 'St. Petersburg', 'Ukhta');
+CREATE TABLE sales_others2 PARTITION OF sales_list2 DEFAULT;
+CREATE TABLE sales_external (LIKE sales_list);
+CREATE TABLE sales_external2 (vch VARCHAR(5));
+-- ERROR:  partition bound for relation "sales_external" is null
+ALTER TABLE sales_list MERGE PARTITIONS (sales_west, sales_east, sales_external) INTO sales_all;
+ERROR:  partition bound for relation "sales_external" is null
+-- ERROR:  partition bound for relation "sales_external2" is null
+ALTER TABLE sales_list MERGE PARTITIONS (sales_west, sales_east, sales_external2) INTO sales_all;
+ERROR:  partition bound for relation "sales_external2" is null
+-- ERROR:  relation "sales_nord2" is not a partition of relation "sales_list"
+ALTER TABLE sales_list MERGE PARTITIONS (sales_west, sales_nord2, sales_east) INTO sales_all;
+ERROR:  relation "sales_nord2" is not a partition of relation "sales_list"
+DROP TABLE sales_external2;
+DROP TABLE sales_external;
+DROP TABLE sales_list2;
+DROP TABLE sales_list;
+--
+-- Test: BY LIST partitioning, MERGE PARTITIONS with data
+--
+CREATE TABLE sales_list
+(salesman_id INT GENERATED ALWAYS AS IDENTITY,
+ salesman_name VARCHAR(30),
+ sales_state VARCHAR(20),
+ sales_amount INT,
+ sales_date DATE)
+PARTITION BY LIST (sales_state);
+CREATE INDEX sales_list_salesman_name_idx ON sales_list USING btree (salesman_name);
+CREATE INDEX sales_list_sales_state_idx ON sales_list USING btree (sales_state);
+CREATE TABLE sales_nord PARTITION OF sales_list FOR VALUES IN ('Murmansk', 'St. Petersburg', 'Ukhta');
+CREATE TABLE sales_west PARTITION OF sales_list FOR VALUES IN ('Voronezh', 'Smolensk', 'Bryansk');
+CREATE TABLE sales_east PARTITION OF sales_list FOR VALUES IN ('Magadan', 'Khabarovsk', 'Vladivostok');
+CREATE TABLE sales_central PARTITION OF sales_list FOR VALUES IN ('Moscow', 'Kazan', 'Volgograd');
+CREATE TABLE sales_others PARTITION OF sales_list DEFAULT;
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('Trump',    'Magadan',        1000, '2022-03-01');
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('Smirnoff', 'Smolensk',       500,  '2022-03-03');
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('Ford',     'St. Petersburg', 2000, '2022-03-05');
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('Ivanov',   'Moscow',         750,  '2022-03-04');
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('Deev',     'Voronezh',       250,  '2022-03-07');
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('Poirot',   'Kazan',          1000, '2022-03-01');
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('May',      'Ukhta',          1200, '2022-03-06');
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('Li',       'Vladivostok',    1150, '2022-03-09');
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('May',      'Ukhta',          1200, '2022-03-11');
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('Halder',   'Murmansk',       800,  '2022-03-02');
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('Muller',   'Bryansk',        650,  '2022-03-05');
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('Smith',    'Volgograd',      350,  '2022-03-10');
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('Gandi',    'Moscow',         150,  '2022-03-08');
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('Plato',    'Voronezh',       950,  '2022-03-05');
+-- show partitions with conditions:
+SELECT c.oid::pg_catalog.regclass, c.relkind, inhdetachpending, pg_catalog.pg_get_expr(c.relpartbound, c.oid)
+  FROM pg_catalog.pg_class c, pg_catalog.pg_inherits i
+  WHERE c.oid = i.inhrelid AND i.inhparent = 'sales_list'::regclass
+  ORDER BY pg_catalog.pg_get_expr(c.relpartbound, c.oid) = 'DEFAULT', c.oid::pg_catalog.regclass::pg_catalog.text;
+      oid      | relkind | inhdetachpending |                      pg_get_expr                       
+---------------+---------+------------------+--------------------------------------------------------
+ sales_central | r       | f                | FOR VALUES IN ('Moscow', 'Kazan', 'Volgograd')
+ sales_east    | r       | f                | FOR VALUES IN ('Magadan', 'Khabarovsk', 'Vladivostok')
+ sales_nord    | r       | f                | FOR VALUES IN ('Murmansk', 'St. Petersburg', 'Ukhta')
+ sales_west    | r       | f                | FOR VALUES IN ('Voronezh', 'Smolensk', 'Bryansk')
+ sales_others  | r       | f                | DEFAULT
+(5 rows)
+
+ALTER TABLE sales_list MERGE PARTITIONS (sales_west, sales_east, sales_central) INTO sales_all;
+-- show partitions with conditions:
+SELECT c.oid::pg_catalog.regclass, c.relkind, inhdetachpending, pg_catalog.pg_get_expr(c.relpartbound, c.oid)
+  FROM pg_catalog.pg_class c, pg_catalog.pg_inherits i
+  WHERE c.oid = i.inhrelid AND i.inhparent = 'sales_list'::regclass
+  ORDER BY pg_catalog.pg_get_expr(c.relpartbound, c.oid) = 'DEFAULT', c.oid::pg_catalog.regclass::pg_catalog.text;
+     oid      | relkind | inhdetachpending |                                                        pg_get_expr                                                        
+--------------+---------+------------------+---------------------------------------------------------------------------------------------------------------------------
+ sales_all    | r       | f                | FOR VALUES IN ('Voronezh', 'Smolensk', 'Bryansk', 'Magadan', 'Khabarovsk', 'Vladivostok', 'Moscow', 'Kazan', 'Volgograd')
+ sales_nord   | r       | f                | FOR VALUES IN ('Murmansk', 'St. Petersburg', 'Ukhta')
+ sales_others | r       | f                | DEFAULT
+(3 rows)
+
+SELECT * FROM sales_list;
+ salesman_id | salesman_name |  sales_state   | sales_amount | sales_date 
+-------------+---------------+----------------+--------------+------------
+           2 | Smirnoff      | Smolensk       |          500 | 03-03-2022
+           5 | Deev          | Voronezh       |          250 | 03-07-2022
+          11 | Muller        | Bryansk        |          650 | 03-05-2022
+          14 | Plato         | Voronezh       |          950 | 03-05-2022
+           1 | Trump         | Magadan        |         1000 | 03-01-2022
+           8 | Li            | Vladivostok    |         1150 | 03-09-2022
+           4 | Ivanov        | Moscow         |          750 | 03-04-2022
+           6 | Poirot        | Kazan          |         1000 | 03-01-2022
+          12 | Smith         | Volgograd      |          350 | 03-10-2022
+          13 | Gandi         | Moscow         |          150 | 03-08-2022
+           3 | Ford          | St. Petersburg |         2000 | 03-05-2022
+           7 | May           | Ukhta          |         1200 | 03-06-2022
+           9 | May           | Ukhta          |         1200 | 03-11-2022
+          10 | Halder        | Murmansk       |          800 | 03-02-2022
+(14 rows)
+
+SELECT * FROM sales_nord;
+ salesman_id | salesman_name |  sales_state   | sales_amount | sales_date 
+-------------+---------------+----------------+--------------+------------
+           3 | Ford          | St. Petersburg |         2000 | 03-05-2022
+           7 | May           | Ukhta          |         1200 | 03-06-2022
+           9 | May           | Ukhta          |         1200 | 03-11-2022
+          10 | Halder        | Murmansk       |          800 | 03-02-2022
+(4 rows)
+
+SELECT * FROM sales_all;
+ salesman_id | salesman_name | sales_state | sales_amount | sales_date 
+-------------+---------------+-------------+--------------+------------
+           2 | Smirnoff      | Smolensk    |          500 | 03-03-2022
+           5 | Deev          | Voronezh    |          250 | 03-07-2022
+          11 | Muller        | Bryansk     |          650 | 03-05-2022
+          14 | Plato         | Voronezh    |          950 | 03-05-2022
+           1 | Trump         | Magadan     |         1000 | 03-01-2022
+           8 | Li            | Vladivostok |         1150 | 03-09-2022
+           4 | Ivanov        | Moscow      |          750 | 03-04-2022
+           6 | Poirot        | Kazan       |         1000 | 03-01-2022
+          12 | Smith         | Volgograd   |          350 | 03-10-2022
+          13 | Gandi         | Moscow      |          150 | 03-08-2022
+(10 rows)
+
+-- Use indexscan for test indexes after merge partitions
+SET enable_indexscan = ON;
+SET enable_seqscan = OFF;
+SELECT * FROM sales_all WHERE sales_state = 'Moscow';
+ salesman_id | salesman_name | sales_state | sales_amount | sales_date 
+-------------+---------------+-------------+--------------+------------
+           4 | Ivanov        | Moscow      |          750 | 03-04-2022
+          13 | Gandi         | Moscow      |          150 | 03-08-2022
+(2 rows)
+
+SELECT * FROM sales_list WHERE sales_state = 'Moscow';
+ salesman_id | salesman_name | sales_state | sales_amount | sales_date 
+-------------+---------------+-------------+--------------+------------
+           4 | Ivanov        | Moscow      |          750 | 03-04-2022
+          13 | Gandi         | Moscow      |          150 | 03-08-2022
+(2 rows)
+
+SELECT * FROM sales_list WHERE salesman_name = 'Ivanov';
+ salesman_id | salesman_name | sales_state | sales_amount | sales_date 
+-------------+---------------+-------------+--------------+------------
+           4 | Ivanov        | Moscow      |          750 | 03-04-2022
+(1 row)
+
+SET enable_indexscan = ON;
+SET enable_seqscan = ON;
+DROP TABLE sales_list;
+--
+DROP SCHEMA partitions_merge_schema;
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index 5ac6e871f54..026e7a77675 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -119,7 +119,7 @@ test: plancache limit plpgsql copy2 temp domain rangefuncs prepare conversion tr
 # The stats test resets stats, so nothing else needing stats access can be in
 # this group.
 # ----------
-test: partition_join partition_prune reloptions hash_part indexing partition_aggregate partition_info tuplesort explain compression memoize stats predicate
+test: partition_merge partition_join partition_prune reloptions hash_part indexing partition_aggregate partition_info tuplesort explain compression memoize stats predicate
 
 # event_trigger depends on create_am and cannot run concurrently with
 # any test that runs DDL
diff --git a/src/test/regress/sql/partition_merge.sql b/src/test/regress/sql/partition_merge.sql
new file mode 100644
index 00000000000..8bf90fd6212
--- /dev/null
+++ b/src/test/regress/sql/partition_merge.sql
@@ -0,0 +1,434 @@
+--
+-- PARTITIONS_MERGE
+-- Tests for "ALTER TABLE ... MERGE PARTITIONS ..." command
+--
+
+CREATE SCHEMA partitions_merge_schema;
+SET search_path = partitions_merge_schema, public;
+
+--
+-- BY RANGE partitioning
+--
+
+--
+-- Test for error codes
+--
+CREATE TABLE sales_range (salesman_id INT, salesman_name VARCHAR(30), sales_amount INT, sales_date DATE) PARTITION BY RANGE (sales_date);
+CREATE TABLE sales_dec2021 PARTITION OF sales_range FOR VALUES FROM ('2021-12-01') TO ('2021-12-31');
+CREATE TABLE sales_jan2022 PARTITION OF sales_range FOR VALUES FROM ('2022-01-01') TO ('2022-02-01');
+CREATE TABLE sales_feb2022 PARTITION OF sales_range FOR VALUES FROM ('2022-02-01') TO ('2022-03-01');
+CREATE TABLE sales_mar2022 PARTITION OF sales_range FOR VALUES FROM ('2022-03-01') TO ('2022-04-01');
+
+CREATE TABLE sales_apr2022 (salesman_id INT, salesman_name VARCHAR(30), sales_amount INT, sales_date DATE) PARTITION BY RANGE (sales_date);
+CREATE TABLE sales_apr_1 PARTITION OF sales_apr2022 FOR VALUES FROM ('2022-04-01') TO ('2022-04-15');
+CREATE TABLE sales_apr_2 PARTITION OF sales_apr2022 FOR VALUES FROM ('2022-04-15') TO ('2022-05-01');
+ALTER TABLE sales_range ATTACH PARTITION sales_apr2022 FOR VALUES FROM ('2022-04-01') TO ('2022-05-01');
+
+CREATE TABLE sales_others PARTITION OF sales_range DEFAULT;
+
+-- ERROR:  partition with name "sales_feb2022" already used
+ALTER TABLE sales_range MERGE PARTITIONS (sales_feb2022, sales_mar2022, sales_feb2022) INTO sales_feb_mar_apr2022;
+-- ERROR:  cannot merge non-table partition "sales_apr2022"
+ALTER TABLE sales_range MERGE PARTITIONS (sales_feb2022, sales_mar2022, sales_apr2022) INTO sales_feb_mar_apr2022;
+-- ERROR:  invalid partitions order, partition "sales_mar2022" can not be merged
+-- (space between sections sales_jan2022 and sales_mar2022)
+ALTER TABLE sales_range MERGE PARTITIONS (sales_jan2022, sales_mar2022) INTO sales_jan_mar2022;
+-- ERROR:  invalid partitions order, partition "sales_jan2022" can not be merged
+-- (space between sections sales_dec2021 and sales_jan2022)
+ALTER TABLE sales_range MERGE PARTITIONS (sales_dec2021, sales_jan2022, sales_feb2022) INTO sales_dec_jan_feb2022;
+
+-- NO ERROR: test for custom partitions order
+ALTER TABLE sales_range MERGE PARTITIONS (sales_feb2022, sales_mar2022, sales_jan2022) INTO sales_jan_feb_mar2022;
+
+SELECT c.oid::pg_catalog.regclass, c.relkind, inhdetachpending, pg_catalog.pg_get_expr(c.relpartbound, c.oid)
+  FROM pg_catalog.pg_class c, pg_catalog.pg_inherits i
+  WHERE c.oid = i.inhrelid AND i.inhparent = 'sales_range'::regclass
+  ORDER BY pg_catalog.pg_get_expr(c.relpartbound, c.oid) = 'DEFAULT', c.oid::pg_catalog.regclass::pg_catalog.text;
+
+DROP TABLE sales_range;
+
+--
+-- Add rows into partitioned table then merge partitions
+--
+CREATE TABLE sales_range (salesman_id INT, salesman_name VARCHAR(30), sales_amount INT, sales_date DATE) PARTITION BY RANGE (sales_date);
+CREATE TABLE sales_jan2022 PARTITION OF sales_range FOR VALUES FROM ('2022-01-01') TO ('2022-02-01');
+CREATE TABLE sales_feb2022 PARTITION OF sales_range FOR VALUES FROM ('2022-02-01') TO ('2022-03-01');
+CREATE TABLE sales_mar2022 PARTITION OF sales_range FOR VALUES FROM ('2022-03-01') TO ('2022-04-01');
+CREATE TABLE sales_apr2022 PARTITION OF sales_range FOR VALUES FROM ('2022-04-01') TO ('2022-05-01');
+CREATE TABLE sales_others PARTITION OF sales_range DEFAULT;
+CREATE INDEX sales_range_sales_date_idx ON sales_range USING btree (sales_date);
+
+INSERT INTO sales_range VALUES (1,  'May',      1000, '2022-01-31');
+INSERT INTO sales_range VALUES (2,  'Smirnoff', 500,  '2022-02-10');
+INSERT INTO sales_range VALUES (3,  'Ford',     2000, '2022-04-30');
+INSERT INTO sales_range VALUES (4,  'Ivanov',   750,  '2022-04-13');
+INSERT INTO sales_range VALUES (5,  'Deev',     250,  '2022-04-07');
+INSERT INTO sales_range VALUES (6,  'Poirot',   150,  '2022-02-11');
+INSERT INTO sales_range VALUES (7,  'Li',       175,  '2022-03-08');
+INSERT INTO sales_range VALUES (8,  'Ericsson', 185,  '2022-02-23');
+INSERT INTO sales_range VALUES (9,  'Muller',   250,  '2022-03-11');
+INSERT INTO sales_range VALUES (10, 'Halder',   350,  '2022-01-28');
+INSERT INTO sales_range VALUES (11, 'Trump',    380,  '2022-04-06');
+INSERT INTO sales_range VALUES (12, 'Plato',    350,  '2022-03-19');
+INSERT INTO sales_range VALUES (13, 'Gandi',    377,  '2022-01-09');
+INSERT INTO sales_range VALUES (14, 'Smith',    510,  '2022-05-04');
+
+SELECT pg_catalog.pg_get_partkeydef('sales_range'::regclass);
+
+-- show partitions with conditions:
+SELECT c.oid::pg_catalog.regclass, c.relkind, inhdetachpending, pg_catalog.pg_get_expr(c.relpartbound, c.oid)
+  FROM pg_catalog.pg_class c, pg_catalog.pg_inherits i
+  WHERE c.oid = i.inhrelid AND i.inhparent = 'sales_range'::regclass
+  ORDER BY pg_catalog.pg_get_expr(c.relpartbound, c.oid) = 'DEFAULT', c.oid::pg_catalog.regclass::pg_catalog.text;
+
+ALTER TABLE sales_range MERGE PARTITIONS (sales_feb2022, sales_mar2022, sales_apr2022) INTO sales_feb_mar_apr2022;
+
+-- show partitions with conditions:
+SELECT c.oid::pg_catalog.regclass, c.relkind, inhdetachpending, pg_catalog.pg_get_expr(c.relpartbound, c.oid)
+  FROM pg_catalog.pg_class c, pg_catalog.pg_inherits i
+  WHERE c.oid = i.inhrelid AND i.inhparent = 'sales_range'::regclass
+  ORDER BY pg_catalog.pg_get_expr(c.relpartbound, c.oid) = 'DEFAULT', c.oid::pg_catalog.regclass::pg_catalog.text;
+
+SELECT * FROM pg_indexes WHERE tablename = 'sales_feb_mar_apr2022' and schemaname = 'partitions_merge_schema';
+
+SELECT * FROM sales_range;
+SELECT * FROM sales_jan2022;
+SELECT * FROM sales_feb_mar_apr2022;
+SELECT * FROM sales_others;
+
+-- Use indexscan for test indexes
+SET enable_indexscan = ON;
+SET enable_seqscan = OFF;
+
+SELECT * FROM sales_feb_mar_apr2022 where sales_date > '2022-01-01';
+
+SET enable_indexscan = ON;
+SET enable_seqscan = ON;
+
+DROP TABLE sales_range;
+
+--
+-- Merge some partitions into DEFAULT partition
+--
+CREATE TABLE sales_range (salesman_id INT, salesman_name VARCHAR(30), sales_amount INT, sales_date DATE) PARTITION BY RANGE (sales_date);
+CREATE TABLE sales_jan2022 PARTITION OF sales_range FOR VALUES FROM ('2022-01-01') TO ('2022-02-01');
+CREATE TABLE sales_feb2022 PARTITION OF sales_range FOR VALUES FROM ('2022-02-01') TO ('2022-03-01');
+CREATE TABLE sales_mar2022 PARTITION OF sales_range FOR VALUES FROM ('2022-03-01') TO ('2022-04-01');
+CREATE TABLE sales_apr2022 PARTITION OF sales_range FOR VALUES FROM ('2022-04-01') TO ('2022-05-01');
+CREATE TABLE sales_others PARTITION OF sales_range DEFAULT;
+CREATE INDEX sales_range_sales_date_idx ON sales_range USING btree (sales_date);
+
+INSERT INTO sales_range VALUES (1,  'May',      1000, '2022-01-31');
+INSERT INTO sales_range VALUES (2,  'Smirnoff', 500,  '2022-02-10');
+INSERT INTO sales_range VALUES (3,  'Ford',     2000, '2022-04-30');
+INSERT INTO sales_range VALUES (4,  'Ivanov',   750,  '2022-04-13');
+INSERT INTO sales_range VALUES (5,  'Deev',     250,  '2022-04-07');
+INSERT INTO sales_range VALUES (6,  'Poirot',   150,  '2022-02-11');
+INSERT INTO sales_range VALUES (7,  'Li',       175,  '2022-03-08');
+INSERT INTO sales_range VALUES (8,  'Ericsson', 185,  '2022-02-23');
+INSERT INTO sales_range VALUES (9,  'Muller',   250,  '2022-03-11');
+INSERT INTO sales_range VALUES (10, 'Halder',   350,  '2022-01-28');
+INSERT INTO sales_range VALUES (11, 'Trump',    380,  '2022-04-06');
+INSERT INTO sales_range VALUES (12, 'Plato',    350,  '2022-03-19');
+INSERT INTO sales_range VALUES (13, 'Gandi',    377,  '2022-01-09');
+INSERT INTO sales_range VALUES (14, 'Smith',    510,  '2022-05-04');
+
+-- Merge partitions (include DEFAULT partition) into partition with the same
+-- name
+ALTER TABLE sales_range MERGE PARTITIONS (sales_jan2022, sales_mar2022, sales_others) INTO sales_others;
+
+select * from sales_others;
+
+-- show partitions with conditions:
+SELECT c.oid::pg_catalog.regclass, c.relkind, inhdetachpending, pg_catalog.pg_get_expr(c.relpartbound, c.oid)
+  FROM pg_catalog.pg_class c, pg_catalog.pg_inherits i
+  WHERE c.oid = i.inhrelid AND i.inhparent = 'sales_range'::regclass
+  ORDER BY pg_catalog.pg_get_expr(c.relpartbound, c.oid) = 'DEFAULT', c.oid::pg_catalog.regclass::pg_catalog.text;
+
+DROP TABLE sales_range;
+
+--
+-- Test for:
+--   * composite partition key;
+--   * GENERATED column;
+--   * column with DEFAULT value.
+--
+CREATE TABLE sales_date (salesman_name VARCHAR(30), sales_year INT, sales_month INT, sales_day INT,
+  sales_date VARCHAR(10) GENERATED ALWAYS AS
+    (LPAD(sales_year::text, 4, '0') || '.' || LPAD(sales_month::text, 2, '0') || '.' || LPAD(sales_day::text, 2, '0')) STORED,
+  sales_department VARCHAR(30) DEFAULT 'Sales department')
+  PARTITION BY RANGE (sales_year, sales_month, sales_day);
+
+CREATE TABLE sales_dec2022 PARTITION OF sales_date FOR VALUES FROM (2021, 12, 1) TO (2022, 1, 1);
+CREATE TABLE sales_jan2022 PARTITION OF sales_date FOR VALUES FROM (2022, 1, 1) TO (2022, 2, 1);
+CREATE TABLE sales_feb2022 PARTITION OF sales_date FOR VALUES FROM (2022, 2, 1) TO (2022, 3, 1);
+CREATE TABLE sales_other PARTITION OF sales_date FOR VALUES FROM (2022, 3, 1) TO (MAXVALUE, MAXVALUE, MAXVALUE);
+
+INSERT INTO sales_date(salesman_name, sales_year, sales_month, sales_day) VALUES ('Manager1', 2021, 12, 7);
+INSERT INTO sales_date(salesman_name, sales_year, sales_month, sales_day) VALUES ('Manager2', 2021, 12, 8);
+INSERT INTO sales_date(salesman_name, sales_year, sales_month, sales_day) VALUES ('Manager3', 2022, 1, 1);
+INSERT INTO sales_date(salesman_name, sales_year, sales_month, sales_day) VALUES ('Manager1', 2022, 2, 4);
+INSERT INTO sales_date(salesman_name, sales_year, sales_month, sales_day) VALUES ('Manager2', 2022, 1, 2);
+INSERT INTO sales_date(salesman_name, sales_year, sales_month, sales_day) VALUES ('Manager3', 2022, 2, 1);
+INSERT INTO sales_date(salesman_name, sales_year, sales_month, sales_day) VALUES ('Manager1', 2022, 3, 3);
+INSERT INTO sales_date(salesman_name, sales_year, sales_month, sales_day) VALUES ('Manager2', 2022, 3, 4);
+INSERT INTO sales_date(salesman_name, sales_year, sales_month, sales_day) VALUES ('Manager3', 2022, 5, 1);
+
+SELECT * FROM sales_date;
+SELECT * FROM sales_dec2022;
+SELECT * FROM sales_jan2022;
+SELECT * FROM sales_feb2022;
+SELECT * FROM sales_other;
+
+ALTER TABLE sales_date MERGE PARTITIONS (sales_jan2022, sales_feb2022) INTO sales_jan_feb2022;
+
+INSERT INTO sales_date(salesman_name, sales_year, sales_month, sales_day) VALUES ('Manager1', 2022, 1, 10);
+INSERT INTO sales_date(salesman_name, sales_year, sales_month, sales_day) VALUES ('Manager2', 2022, 2, 10);
+
+SELECT * FROM sales_date;
+SELECT * FROM sales_dec2022;
+SELECT * FROM sales_jan_feb2022;
+SELECT * FROM sales_other;
+
+DROP TABLE sales_date;
+
+--
+-- Test: merge partitions of partitioned table with triggers
+--
+CREATE TABLE salesmans(salesman_id INT PRIMARY KEY, salesman_name VARCHAR(30)) PARTITION BY RANGE (salesman_id);
+
+CREATE TABLE salesmans01_10 PARTITION OF salesmans FOR VALUES FROM (1) TO (10);
+CREATE TABLE salesmans10_20 PARTITION OF salesmans FOR VALUES FROM (10) TO (20);
+CREATE TABLE salesmans20_30 PARTITION OF salesmans FOR VALUES FROM (20) TO (30);
+CREATE TABLE salesmans30_40 PARTITION OF salesmans FOR VALUES FROM (30) TO (40);
+
+INSERT INTO salesmans VALUES (1,  'Poirot');
+
+CREATE OR REPLACE FUNCTION after_insert_row_trigger() RETURNS trigger LANGUAGE 'plpgsql' AS $BODY$
+BEGIN
+	RAISE NOTICE 'trigger(%) called: action = %, when = %, level = %', TG_ARGV[0], TG_OP, TG_WHEN, TG_LEVEL;
+    RETURN NULL;
+END;
+$BODY$;
+
+CREATE TRIGGER salesmans_after_insert_statement_trigger
+    AFTER INSERT
+    ON salesmans
+    FOR EACH STATEMENT
+    EXECUTE PROCEDURE after_insert_row_trigger('salesmans');
+
+CREATE TRIGGER salesmans_after_insert_row_trigger
+    AFTER INSERT
+    ON salesmans
+    FOR EACH ROW
+    EXECUTE PROCEDURE after_insert_row_trigger('salesmans');
+
+-- 2 triggers should fire here (row + statement):
+INSERT INTO salesmans VALUES (10, 'May');
+-- 1 trigger should fire here (row):
+INSERT INTO salesmans10_20 VALUES (19, 'Ivanov');
+
+ALTER TABLE salesmans MERGE PARTITIONS (salesmans10_20, salesmans20_30, salesmans30_40) INTO salesmans10_40;
+
+-- 2 triggers should fire here (row + statement):
+INSERT INTO salesmans VALUES (20, 'Smirnoff');
+-- 1 trigger should fire here (row):
+INSERT INTO salesmans10_40 VALUES (30, 'Ford');
+
+SELECT * FROM salesmans01_10;
+SELECT * FROM salesmans10_40;
+
+DROP TABLE salesmans;
+DROP FUNCTION after_insert_row_trigger();
+
+--
+-- Test: merge partitions with deleted columns
+--
+CREATE TABLE salesmans(salesman_id INT PRIMARY KEY, salesman_name VARCHAR(30)) PARTITION BY RANGE (salesman_id);
+
+CREATE TABLE salesmans01_10 PARTITION OF salesmans FOR VALUES FROM (1) TO (10);
+-- Create partitions with some deleted columns:
+CREATE TABLE salesmans10_20(d1 VARCHAR(30), salesman_id INT PRIMARY KEY, salesman_name VARCHAR(30));
+CREATE TABLE salesmans20_30(salesman_id INT PRIMARY KEY, d2 INT,  salesman_name VARCHAR(30));
+CREATE TABLE salesmans30_40(salesman_id INT PRIMARY KEY, d3 DATE, salesman_name VARCHAR(30));
+
+INSERT INTO salesmans10_20 VALUES ('dummy value 1', 19, 'Ivanov');
+INSERT INTO salesmans20_30 VALUES (20, 101, 'Smirnoff');
+INSERT INTO salesmans30_40 VALUES (31, now(), 'Popov');
+
+ALTER TABLE salesmans10_20 DROP COLUMN d1;
+ALTER TABLE salesmans20_30 DROP COLUMN d2;
+ALTER TABLE salesmans30_40 DROP COLUMN d3;
+
+ALTER TABLE salesmans ATTACH PARTITION salesmans10_20 FOR VALUES FROM (10) TO (20);
+ALTER TABLE salesmans ATTACH PARTITION salesmans20_30 FOR VALUES FROM (20) TO (30);
+ALTER TABLE salesmans ATTACH PARTITION salesmans30_40 FOR VALUES FROM (30) TO (40);
+
+INSERT INTO salesmans VALUES (1, 'Poirot');
+INSERT INTO salesmans VALUES (10, 'May');
+INSERT INTO salesmans VALUES (30, 'Ford');
+
+ALTER TABLE salesmans MERGE PARTITIONS (salesmans10_20, salesmans20_30, salesmans30_40) INTO salesmans10_40;
+
+select * from salesmans;
+select * from salesmans01_10;
+select * from salesmans10_40;
+
+DROP TABLE salesmans;
+
+--
+-- Test: merge sub-partitions
+--
+CREATE TABLE sales_range (salesman_id INT, salesman_name VARCHAR(30), sales_amount INT, sales_date DATE) PARTITION BY RANGE (sales_date);
+CREATE TABLE sales_jan2022 PARTITION OF sales_range FOR VALUES FROM ('2022-01-01') TO ('2022-02-01');
+CREATE TABLE sales_feb2022 PARTITION OF sales_range FOR VALUES FROM ('2022-02-01') TO ('2022-03-01');
+CREATE TABLE sales_mar2022 PARTITION OF sales_range FOR VALUES FROM ('2022-03-01') TO ('2022-04-01');
+
+CREATE TABLE sales_apr2022 (salesman_id INT, salesman_name VARCHAR(30), sales_amount INT, sales_date DATE) PARTITION BY RANGE (sales_date);
+CREATE TABLE sales_apr2022_01_10 PARTITION OF sales_apr2022 FOR VALUES FROM ('2022-04-01') TO ('2022-04-10');
+CREATE TABLE sales_apr2022_10_20 PARTITION OF sales_apr2022 FOR VALUES FROM ('2022-04-10') TO ('2022-04-20');
+CREATE TABLE sales_apr2022_20_30 PARTITION OF sales_apr2022 FOR VALUES FROM ('2022-04-20') TO ('2022-05-01');
+ALTER TABLE sales_range ATTACH PARTITION sales_apr2022 FOR VALUES FROM ('2022-04-01') TO ('2022-05-01');
+
+CREATE TABLE sales_others PARTITION OF sales_range DEFAULT;
+
+CREATE INDEX sales_range_sales_date_idx ON sales_range USING btree (sales_date);
+
+INSERT INTO sales_range VALUES (1,  'May',      1000, '2022-01-31');
+INSERT INTO sales_range VALUES (2,  'Smirnoff', 500,  '2022-02-10');
+INSERT INTO sales_range VALUES (3,  'Ford',     2000, '2022-04-30');
+INSERT INTO sales_range VALUES (4,  'Ivanov',   750,  '2022-04-13');
+INSERT INTO sales_range VALUES (5,  'Deev',     250,  '2022-04-07');
+INSERT INTO sales_range VALUES (6,  'Poirot',   150,  '2022-02-11');
+INSERT INTO sales_range VALUES (7,  'Li',       175,  '2022-03-08');
+INSERT INTO sales_range VALUES (8,  'Ericsson', 185,  '2022-02-23');
+INSERT INTO sales_range VALUES (9,  'Muller',   250,  '2022-03-11');
+INSERT INTO sales_range VALUES (10, 'Halder',   350,  '2022-01-28');
+INSERT INTO sales_range VALUES (11, 'Trump',    380,  '2022-04-06');
+INSERT INTO sales_range VALUES (12, 'Plato',    350,  '2022-03-19');
+INSERT INTO sales_range VALUES (13, 'Gandi',    377,  '2022-01-09');
+INSERT INTO sales_range VALUES (14, 'Smith',    510,  '2022-05-04');
+
+SELECT * FROM sales_range;
+SELECT * FROM sales_apr2022;
+SELECT * FROM sales_apr2022_01_10;
+SELECT * FROM sales_apr2022_10_20;
+SELECT * FROM sales_apr2022_20_30;
+
+ALTER TABLE sales_apr2022 MERGE PARTITIONS (sales_apr2022_01_10, sales_apr2022_10_20, sales_apr2022_20_30) INTO sales_apr_all;
+
+SELECT * FROM sales_range;
+SELECT * FROM sales_apr2022;
+SELECT * FROM sales_apr_all;
+
+DROP TABLE sales_range;
+
+--
+-- BY LIST partitioning
+--
+
+--
+-- Test: specific errors for BY LIST partitioning
+--
+CREATE TABLE sales_list
+(salesman_id INT GENERATED ALWAYS AS IDENTITY,
+ salesman_name VARCHAR(30),
+ sales_state VARCHAR(20),
+ sales_amount INT,
+ sales_date DATE)
+PARTITION BY LIST (sales_state);
+CREATE TABLE sales_nord PARTITION OF sales_list FOR VALUES IN ('Murmansk', 'St. Petersburg', 'Ukhta');
+CREATE TABLE sales_west PARTITION OF sales_list FOR VALUES IN ('Voronezh', 'Smolensk', 'Bryansk');
+CREATE TABLE sales_east PARTITION OF sales_list FOR VALUES IN ('Magadan', 'Khabarovsk', 'Vladivostok');
+CREATE TABLE sales_central PARTITION OF sales_list FOR VALUES IN ('Moscow', 'Kazan', 'Volgograd');
+CREATE TABLE sales_others PARTITION OF sales_list DEFAULT;
+
+
+CREATE TABLE sales_list2 (LIKE sales_list) PARTITION BY LIST (sales_state);
+CREATE TABLE sales_nord2 PARTITION OF sales_list2 FOR VALUES IN ('Murmansk', 'St. Petersburg', 'Ukhta');
+CREATE TABLE sales_others2 PARTITION OF sales_list2 DEFAULT;
+
+
+CREATE TABLE sales_external (LIKE sales_list);
+CREATE TABLE sales_external2 (vch VARCHAR(5));
+
+-- ERROR:  partition bound for relation "sales_external" is null
+ALTER TABLE sales_list MERGE PARTITIONS (sales_west, sales_east, sales_external) INTO sales_all;
+-- ERROR:  partition bound for relation "sales_external2" is null
+ALTER TABLE sales_list MERGE PARTITIONS (sales_west, sales_east, sales_external2) INTO sales_all;
+-- ERROR:  relation "sales_nord2" is not a partition of relation "sales_list"
+ALTER TABLE sales_list MERGE PARTITIONS (sales_west, sales_nord2, sales_east) INTO sales_all;
+
+DROP TABLE sales_external2;
+DROP TABLE sales_external;
+DROP TABLE sales_list2;
+DROP TABLE sales_list;
+
+--
+-- Test: BY LIST partitioning, MERGE PARTITIONS with data
+--
+CREATE TABLE sales_list
+(salesman_id INT GENERATED ALWAYS AS IDENTITY,
+ salesman_name VARCHAR(30),
+ sales_state VARCHAR(20),
+ sales_amount INT,
+ sales_date DATE)
+PARTITION BY LIST (sales_state);
+
+CREATE INDEX sales_list_salesman_name_idx ON sales_list USING btree (salesman_name);
+CREATE INDEX sales_list_sales_state_idx ON sales_list USING btree (sales_state);
+
+CREATE TABLE sales_nord PARTITION OF sales_list FOR VALUES IN ('Murmansk', 'St. Petersburg', 'Ukhta');
+CREATE TABLE sales_west PARTITION OF sales_list FOR VALUES IN ('Voronezh', 'Smolensk', 'Bryansk');
+CREATE TABLE sales_east PARTITION OF sales_list FOR VALUES IN ('Magadan', 'Khabarovsk', 'Vladivostok');
+CREATE TABLE sales_central PARTITION OF sales_list FOR VALUES IN ('Moscow', 'Kazan', 'Volgograd');
+CREATE TABLE sales_others PARTITION OF sales_list DEFAULT;
+
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('Trump',    'Magadan',        1000, '2022-03-01');
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('Smirnoff', 'Smolensk',       500,  '2022-03-03');
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('Ford',     'St. Petersburg', 2000, '2022-03-05');
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('Ivanov',   'Moscow',         750,  '2022-03-04');
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('Deev',     'Voronezh',       250,  '2022-03-07');
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('Poirot',   'Kazan',          1000, '2022-03-01');
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('May',      'Ukhta',          1200, '2022-03-06');
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('Li',       'Vladivostok',    1150, '2022-03-09');
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('May',      'Ukhta',          1200, '2022-03-11');
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('Halder',   'Murmansk',       800,  '2022-03-02');
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('Muller',   'Bryansk',        650,  '2022-03-05');
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('Smith',    'Volgograd',      350,  '2022-03-10');
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('Gandi',    'Moscow',         150,  '2022-03-08');
+INSERT INTO sales_list (salesman_name, sales_state, sales_amount, sales_date) VALUES ('Plato',    'Voronezh',       950,  '2022-03-05');
+
+-- show partitions with conditions:
+SELECT c.oid::pg_catalog.regclass, c.relkind, inhdetachpending, pg_catalog.pg_get_expr(c.relpartbound, c.oid)
+  FROM pg_catalog.pg_class c, pg_catalog.pg_inherits i
+  WHERE c.oid = i.inhrelid AND i.inhparent = 'sales_list'::regclass
+  ORDER BY pg_catalog.pg_get_expr(c.relpartbound, c.oid) = 'DEFAULT', c.oid::pg_catalog.regclass::pg_catalog.text;
+
+ALTER TABLE sales_list MERGE PARTITIONS (sales_west, sales_east, sales_central) INTO sales_all;
+
+-- show partitions with conditions:
+SELECT c.oid::pg_catalog.regclass, c.relkind, inhdetachpending, pg_catalog.pg_get_expr(c.relpartbound, c.oid)
+  FROM pg_catalog.pg_class c, pg_catalog.pg_inherits i
+  WHERE c.oid = i.inhrelid AND i.inhparent = 'sales_list'::regclass
+  ORDER BY pg_catalog.pg_get_expr(c.relpartbound, c.oid) = 'DEFAULT', c.oid::pg_catalog.regclass::pg_catalog.text;
+
+SELECT * FROM sales_list;
+SELECT * FROM sales_nord;
+SELECT * FROM sales_all;
+
+-- Use indexscan for test indexes after merge partitions
+SET enable_indexscan = ON;
+SET enable_seqscan = OFF;
+
+SELECT * FROM sales_all WHERE sales_state = 'Moscow';
+SELECT * FROM sales_list WHERE sales_state = 'Moscow';
+SELECT * FROM sales_list WHERE salesman_name = 'Ivanov';
+
+SET enable_indexscan = ON;
+SET enable_seqscan = ON;
+
+DROP TABLE sales_list;
+
+--
+DROP SCHEMA partitions_merge_schema;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index cfa9d5aaeac..aa3025676fd 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -2602,6 +2602,7 @@ SimpleStats
 SimpleStringList
 SimpleStringListCell
 SingleBoundSortItem
+SinglePartitionSpec
 Size
 SkipPages
 SlabBlock
-- 
2.39.3 (Apple Git-145)

