Revert "Modified files for MERGE"

This reverts commit 354f13855e.

src/include/access/heapam.h

@@ -53,34 +53,23 @@ typedef enum LockTupleMode
  * When heap_update, heap_delete, or heap_lock_tuple fail because the target
  * tuple is already outdated, they fill in this struct to provide information
  * to the caller about what happened.
- *
- * result is the result of HeapTupleSatisfiesUpdate, leading to the failure.
- * It's set to HeapTupleMayBeUpdated when there is no failure.
- *
  * ctid is the target's ctid link: it is the same as the target's TID if the
  * target was deleted, or the location of the replacement tuple if the target
  * was updated.
- *
  * xmax is the outdating transaction's XID.  If the caller wants to visit the
  * replacement tuple, it must check that this matches before believing the
  * replacement is really a match.
- *
  * cmax is the outdating command's CID, but only when the failure code is
  * HeapTupleSelfUpdated (i.e., something in the current transaction outdated
  * the tuple); otherwise cmax is zero.  (We make this restriction because
  * HeapTupleHeaderGetCmax doesn't work for tuples outdated in other
  * transactions.)
- *
- * lockmode is only relevant for callers of heap_update() and is the mode which
- * the caller should use in case it needs to lock the updated tuple.
  */
 typedef struct HeapUpdateFailureData
 {
-	HTSU_Result result;
 	ItemPointerData ctid;
 	TransactionId xmax;
 	CommandId	cmax;
-	LockTupleMode	lockmode;
 } HeapUpdateFailureData;
 
 
@@ -173,7 +162,7 @@ extern void heap_abort_speculative(Relation relation, HeapTuple tuple);
 extern HTSU_Result heap_update(Relation relation, ItemPointer otid,
 			HeapTuple newtup,
 			CommandId cid, Snapshot crosscheck, bool wait,
-			HeapUpdateFailureData *hufd);
+			HeapUpdateFailureData *hufd, LockTupleMode *lockmode);
 extern HTSU_Result heap_lock_tuple(Relation relation, HeapTuple tuple,
 				CommandId cid, LockTupleMode mode, LockWaitPolicy wait_policy,
 				bool follow_update,

src/include/commands/trigger.h

@@ -206,8 +206,7 @@ extern bool ExecBRDeleteTriggers(EState *estate,
 					 EPQState *epqstate,
 					 ResultRelInfo *relinfo,
 					 ItemPointer tupleid,
-					 HeapTuple fdw_trigtuple,
-					 HeapUpdateFailureData *hufdp);
+					 HeapTuple fdw_trigtuple);
 extern void ExecARDeleteTriggers(EState *estate,
 					 ResultRelInfo *relinfo,
 					 ItemPointer tupleid,
@@ -226,8 +225,7 @@ extern TupleTableSlot *ExecBRUpdateTriggers(EState *estate,
 					 ResultRelInfo *relinfo,
 					 ItemPointer tupleid,
 					 HeapTuple fdw_trigtuple,
-					 TupleTableSlot *slot,
-					 HeapUpdateFailureData *hufdp);
+					 TupleTableSlot *slot);
 extern void ExecARUpdateTriggers(EState *estate,
 					 ResultRelInfo *relinfo,
 					 ItemPointer tupleid,

src/include/executor/execPartition.h

@@ -114,7 +114,6 @@ extern int ExecFindPartition(ResultRelInfo *resultRelInfo,
 				  PartitionDispatch *pd,
 				  TupleTableSlot *slot,
 				  EState *estate);
-extern int ExecFindPartitionByOid(PartitionTupleRouting *proute, Oid partoid);
 extern ResultRelInfo *ExecInitPartitionInfo(ModifyTableState *mtstate,
 					ResultRelInfo *resultRelInfo,
 					PartitionTupleRouting *proute,

src/include/executor/instrument.h

@@ -58,11 +58,8 @@ typedef struct Instrumentation
 	double		total;			/* Total total time (in seconds) */
 	double		ntuples;		/* Total tuples produced */
 	double		nloops;			/* # of run cycles for this node */
-	double		nfiltered1;		/* # tuples removed by scanqual or joinqual OR
-								 * # tuples inserted by MERGE */
-	double		nfiltered2;		/* # tuples removed by "other" quals OR
-								 * # tuples updated by MERGE */
-	double		nfiltered3;		/* # tuples deleted by MERGE */
+	double		nfiltered1;		/* # tuples removed by scanqual or joinqual */
+	double		nfiltered2;		/* # tuples removed by "other" quals */
 	BufferUsage bufusage;		/* Total buffer usage */
 } Instrumentation;
 

src/include/executor/nodeModifyTable.h

@@ -18,26 +18,5 @@
 extern ModifyTableState *ExecInitModifyTable(ModifyTable *node, EState *estate, int eflags);
 extern void ExecEndModifyTable(ModifyTableState *node);
 extern void ExecReScanModifyTable(ModifyTableState *node);
-extern TupleTableSlot *ExecPrepareTupleRouting(ModifyTableState *mtstate,
-						EState *estate,
-						struct PartitionTupleRouting *proute,
-						ResultRelInfo *targetRelInfo,
-						TupleTableSlot *slot);
-extern TupleTableSlot *ExecDelete(ModifyTableState *mtstate,
-		   ItemPointer tupleid, HeapTuple oldtuple, TupleTableSlot *planSlot,
-		   EPQState *epqstate, EState *estate, bool *tupleDeleted,
-		   bool processReturning, HeapUpdateFailureData *hufdp,
-		   MergeActionState *actionState, bool canSetTag);
-extern TupleTableSlot *ExecUpdate(ModifyTableState *mtstate,
-		   ItemPointer tupleid, HeapTuple oldtuple, TupleTableSlot *slot,
-		   TupleTableSlot *planSlot, EPQState *epqstate, EState *estate,
-		   bool *tuple_updated, HeapUpdateFailureData *hufdp,
-		   MergeActionState *actionState, bool canSetTag);
-extern TupleTableSlot *ExecInsert(ModifyTableState *mtstate,
-		   TupleTableSlot *slot,
-		   TupleTableSlot *planSlot,
-		   EState *estate,
-		   MergeActionState *actionState,
-		   bool canSetTag);
 
 #endif							/* NODEMODIFYTABLE_H */

src/include/executor/spi.h

@@ -64,7 +64,6 @@ typedef struct _SPI_plan *SPIPlanPtr;
 #define SPI_OK_REL_REGISTER		15
 #define SPI_OK_REL_UNREGISTER	16
 #define SPI_OK_TD_REGISTER		17
-#define SPI_OK_MERGE			18
 
 #define SPI_OPT_NONATOMIC		(1 << 0)
 

src/include/nodes/execnodes.h

@@ -360,17 +360,8 @@ typedef struct JunkFilter
 	AttrNumber *jf_cleanMap;
 	TupleTableSlot *jf_resultSlot;
 	AttrNumber	jf_junkAttNo;
-	AttrNumber	jf_otherJunkAttNo;
 } JunkFilter;
 
-typedef struct MergeState
-{
-	/* List of MERGE MATCHED action states */
-	List		   *matchedActionStates;
-	/* List of MERGE NOT MATCHED action states */
-	List		   *notMatchedActionStates;
-} MergeState;
-
 /*
  * OnConflictSetState
  *
@@ -461,38 +452,8 @@ typedef struct ResultRelInfo
 
 	/* relation descriptor for root partitioned table */
 	Relation	ri_PartitionRoot;
-
-	int			ri_PartitionLeafIndex;
-	/* for running MERGE on this result relation */
-	MergeState *ri_mergeState;
-
-	/*
-	 * While executing MERGE, the target relation is processed twice; once
-	 * as a target relation and once to run a join between the target and the
-	 * source. We generate two different RTEs for these two purposes, one with
-	 * rte->inh set to false and other with rte->inh set to true.
-	 *
-	 * Since the plan re-evaluated by EvalPlanQual uses the join RTE, we must
-	 * install the updated tuple in the scan corresponding to that RTE. The
-	 * following member tracks the index of the second RTE for EvalPlanQual
-	 * purposes. ri_mergeTargetRTI is non-zero only when MERGE is in-progress.
-	 * We use ri_mergeTargetRTI to run EvalPlanQual for MERGE and
-	 * ri_RangeTableIndex elsewhere.
-	 */
-	Index		ri_mergeTargetRTI;
 } ResultRelInfo;
 
-/*
- * Get the Range table index for EvalPlanQual.
- *
- * We use the ri_mergeTargetRTI if set, otherwise use ri_RangeTableIndex.
- * ri_mergeTargetRTI should really be ever set iff we're running MERGE.
- */
-#define GetEPQRangeTableIndex(r) \
-	(((r)->ri_mergeTargetRTI > 0)  \
-	 ? (r)->ri_mergeTargetRTI \
-	 : (r)->ri_RangeTableIndex)
-
 /* ----------------
  *	  EState information
  *
@@ -1005,11 +966,6 @@ typedef struct PlanState
 		if (((PlanState *)(node))->instrument) \
 			((PlanState *)(node))->instrument->nfiltered2 += (delta); \
 	} while(0)
-#define InstrCountFiltered3(node, delta) \
-	do { \
-		if (((PlanState *)(node))->instrument) \
-			((PlanState *)(node))->instrument->nfiltered3 += (delta); \
-	} while(0)
 
 /*
  * EPQState is state for executing an EvalPlanQual recheck on a candidate
@@ -1056,20 +1012,6 @@ typedef struct ProjectSetState
 	MemoryContext argcontext;	/* context for SRF arguments */
 } ProjectSetState;
 
-/* ----------------
- *	 MergeActionState information
- * ----------------
- */
-typedef struct MergeActionState
-{
-	NodeTag		type;
-	bool		matched;		/* true=MATCHED, false=NOT MATCHED */
-	ExprState  *whenqual;		/* WHEN AND conditions */
-	CmdType		commandType;	/* INSERT/UPDATE/DELETE/DO NOTHING */
-	ProjectionInfo *proj;		/* tuple projection info */
-	TupleDesc	tupDesc;		/* tuple descriptor for projection */
-} MergeActionState;
-
 /* ----------------
  *	 ModifyTableState information
  * ----------------
@@ -1077,7 +1019,7 @@ typedef struct MergeActionState
 typedef struct ModifyTableState
 {
 	PlanState	ps;				/* its first field is NodeTag */
-	CmdType		operation;		/* INSERT, UPDATE, DELETE or MERGE */
+	CmdType		operation;		/* INSERT, UPDATE, or DELETE */
 	bool		canSetTag;		/* do we set the command tag/es_processed? */
 	bool		mt_done;		/* are we done? */
 	PlanState **mt_plans;		/* subplans (one per target rel) */
@@ -1093,8 +1035,6 @@ typedef struct ModifyTableState
 	List	   *mt_excludedtlist;	/* the excluded pseudo relation's tlist  */
 	TupleTableSlot *mt_conflproj;	/* CONFLICT ... SET ... projection target */
 
-	TupleTableSlot *mt_mergeproj;	/* MERGE action projection target */
-
 	/* Tuple-routing support info */
 	struct PartitionTupleRouting *mt_partition_tuple_routing;
 
@@ -1106,9 +1046,6 @@ typedef struct ModifyTableState
 
 	/* Per plan map for tuple conversion from child to root */
 	TupleConversionMap **mt_per_subplan_tupconv_maps;
-
-	/* Flags showing which subcommands are present INS/UPD/DEL/DO NOTHING */
-	int			mt_merge_subcommands;
 } ModifyTableState;
 
 /* ----------------

src/include/nodes/nodes.h

@@ -97,7 +97,6 @@ typedef enum NodeTag
 	T_PlanState,
 	T_ResultState,
 	T_ProjectSetState,
-	T_MergeActionState,
 	T_ModifyTableState,
 	T_AppendState,
 	T_MergeAppendState,
@@ -309,8 +308,6 @@ typedef enum NodeTag
 	T_InsertStmt,
 	T_DeleteStmt,
 	T_UpdateStmt,
-	T_MergeStmt,
-	T_MergeAction,
 	T_SelectStmt,
 	T_AlterTableStmt,
 	T_AlterTableCmd,
@@ -660,8 +657,7 @@ typedef enum CmdType
 	CMD_SELECT,					/* select stmt */
 	CMD_UPDATE,					/* update stmt */
 	CMD_INSERT,					/* insert stmt */
-	CMD_DELETE,					/* delete stmt */
-	CMD_MERGE,					/* merge stmt */
+	CMD_DELETE,
 	CMD_UTILITY,				/* cmds like create, destroy, copy, vacuum,
 								 * etc. */
 	CMD_NOTHING					/* dummy command for instead nothing rules

src/include/nodes/parsenodes.h

@@ -38,7 +38,7 @@ typedef enum OverridingKind
 typedef enum QuerySource
 {
 	QSRC_ORIGINAL,				/* original parsetree (explicit query) */
-	QSRC_PARSER,				/* added by parse analysis in MERGE */
+	QSRC_PARSER,				/* added by parse analysis (now unused) */
 	QSRC_INSTEAD_RULE,			/* added by unconditional INSTEAD rule */
 	QSRC_QUAL_INSTEAD_RULE,		/* added by conditional INSTEAD rule */
 	QSRC_NON_INSTEAD_RULE		/* added by non-INSTEAD rule */
@@ -107,7 +107,7 @@ typedef struct Query
 {
 	NodeTag		type;
 
-	CmdType		commandType;	/* select|insert|update|delete|merge|utility */
+	CmdType		commandType;	/* select|insert|update|delete|utility */
 
 	QuerySource querySource;	/* where did I come from? */
 
@@ -118,7 +118,7 @@ typedef struct Query
 	Node	   *utilityStmt;	/* non-null if commandType == CMD_UTILITY */
 
 	int			resultRelation; /* rtable index of target relation for
-								 * INSERT/UPDATE/DELETE/MERGE; 0 for SELECT */
+								 * INSERT/UPDATE/DELETE; 0 for SELECT */
 
 	bool		hasAggs;		/* has aggregates in tlist or havingQual */
 	bool		hasWindowFuncs; /* has window functions in tlist */
@@ -169,9 +169,6 @@ typedef struct Query
 	List	   *withCheckOptions;	/* a list of WithCheckOption's, which are
 									 * only added during rewrite and therefore
 									 * are not written out as part of Query. */
-	int			mergeTarget_relation;
-	List	   *mergeSourceTargetList;
-	List	   *mergeActionList;	/* list of actions for MERGE (only) */
 
 	/*
 	 * The following two fields identify the portion of the source text string
@@ -1131,9 +1128,7 @@ typedef enum WCOKind
 	WCO_VIEW_CHECK,				/* WCO on an auto-updatable view */
 	WCO_RLS_INSERT_CHECK,		/* RLS INSERT WITH CHECK policy */
 	WCO_RLS_UPDATE_CHECK,		/* RLS UPDATE WITH CHECK policy */
-	WCO_RLS_CONFLICT_CHECK,		/* RLS ON CONFLICT DO UPDATE USING policy */
-	WCO_RLS_MERGE_UPDATE_CHECK, /* RLS MERGE UPDATE USING policy */
-	WCO_RLS_MERGE_DELETE_CHECK	/* RLS MERGE DELETE USING policy */
+	WCO_RLS_CONFLICT_CHECK		/* RLS ON CONFLICT DO UPDATE USING policy */
 } WCOKind;
 
 typedef struct WithCheckOption
@@ -1508,30 +1503,6 @@ typedef struct UpdateStmt
 	WithClause *withClause;		/* WITH clause */
 } UpdateStmt;
 
-/* ----------------------
- *		Merge Statement
- * ----------------------
- */
-typedef struct MergeStmt
-{
-	NodeTag		type;
-	RangeVar   *relation;			/* target relation to merge into */
-	Node	   *source_relation;	/* source relation */
-	Node	   *join_condition; /* join condition between source and target */
-	List	   *mergeActionList;	/* list of MergeAction(s) */
-} MergeStmt;
-
-typedef struct MergeAction
-{
-	NodeTag		type;
-	bool		matched;		/* true=MATCHED, false=NOT MATCHED */
-	Node	   *condition;		/* WHEN AND conditions (raw parser) */
-	Node	   *qual;			/* transformed WHEN AND conditions */
-	CmdType		commandType;	/* INSERT/UPDATE/DELETE/DO NOTHING */
-	Node	   *stmt;			/* T_UpdateStmt etc */
-	List	   *targetList;		/* the target list (of ResTarget) */
-} MergeAction;
-
 /* ----------------------
  *		Select Statement
  *

src/include/nodes/plannodes.h

@@ -18,7 +18,6 @@
 #include "lib/stringinfo.h"
 #include "nodes/bitmapset.h"
 #include "nodes/lockoptions.h"
-#include "nodes/parsenodes.h"
 #include "nodes/primnodes.h"
 
 
@@ -43,7 +42,7 @@ typedef struct PlannedStmt
 {
 	NodeTag		type;
 
-	CmdType		commandType;	/* select|insert|update|delete|merge|utility */
+	CmdType		commandType;	/* select|insert|update|delete|utility */
 
 	uint64		queryId;		/* query identifier (copied from Query) */
 
@@ -217,14 +216,13 @@ typedef struct ProjectSet
 typedef struct ModifyTable
 {
 	Plan		plan;
-	CmdType		operation;		/* INSERT, UPDATE, DELETE or MERGE */
+	CmdType		operation;		/* INSERT, UPDATE, or DELETE */
 	bool		canSetTag;		/* do we set the command tag/es_processed? */
 	Index		nominalRelation;	/* Parent RT index for use of EXPLAIN */
 	/* RT indexes of non-leaf tables in a partition tree */
 	List	   *partitioned_rels;
 	bool		partColsUpdated;	/* some part key in hierarchy updated */
 	List	   *resultRelations;	/* integer list of RT indexes */
-	Index	    mergeTargetRelation;	/* RT index of the merge target */
 	int			resultRelIndex; /* index of first resultRel in plan's list */
 	int			rootResultRelIndex; /* index of the partitioned table root */
 	List	   *plans;			/* plan(s) producing source data */
@@ -240,8 +238,6 @@ typedef struct ModifyTable
 	Node	   *onConflictWhere;	/* WHERE for ON CONFLICT UPDATE */
 	Index		exclRelRTI;		/* RTI of the EXCLUDED pseudo relation */
 	List	   *exclRelTlist;	/* tlist of the EXCLUDED pseudo relation */
-	List	   *mergeSourceTargetList;
-	List	   *mergeActionList;	/* actions for MERGE */
 } ModifyTable;
 
 /* ----------------

src/include/nodes/relation.h

@@ -1670,7 +1670,7 @@ typedef struct LockRowsPath
 } LockRowsPath;
 
 /*
- * ModifyTablePath represents performing INSERT/UPDATE/DELETE/MERGE
+ * ModifyTablePath represents performing INSERT/UPDATE/DELETE modifications
  *
  * We represent most things that will be in the ModifyTable plan node
  * literally, except we have child Path(s) not Plan(s).  But analysis of the
@@ -1679,14 +1679,13 @@ typedef struct LockRowsPath
 typedef struct ModifyTablePath
 {
 	Path		path;
-	CmdType		operation;		/* INSERT, UPDATE, DELETE or MERGE */
+	CmdType		operation;		/* INSERT, UPDATE, or DELETE */
 	bool		canSetTag;		/* do we set the command tag/es_processed? */
 	Index		nominalRelation;	/* Parent RT index for use of EXPLAIN */
 	/* RT indexes of non-leaf tables in a partition tree */
 	List	   *partitioned_rels;
 	bool		partColsUpdated;	/* some part key in hierarchy updated */
 	List	   *resultRelations;	/* integer list of RT indexes */
-	Index	  	mergeTargetRelation;/* RT index of merge target relation */
 	List	   *subpaths;		/* Path(s) producing source data */
 	List	   *subroots;		/* per-target-table PlannerInfos */
 	List	   *withCheckOptionLists;	/* per-target-table WCO lists */
@@ -1694,8 +1693,6 @@ typedef struct ModifyTablePath
 	List	   *rowMarks;		/* PlanRowMarks (non-locking only) */
 	OnConflictExpr *onconflict; /* ON CONFLICT clause, or NULL */
 	int			epqParam;		/* ID of Param for EvalPlanQual re-eval */
-	List	   *mergeSourceTargetList;
-	List	   *mergeActionList;	/* actions for MERGE */
 } ModifyTablePath;
 
 /*

src/include/optimizer/pathnode.h

@@ -241,14 +241,11 @@ extern ModifyTablePath *create_modifytable_path(PlannerInfo *root,
 						CmdType operation, bool canSetTag,
 						Index nominalRelation, List *partitioned_rels,
 						bool partColsUpdated,
-						List *resultRelations,
-						Index	mergeTargetRelation,
-						List *subpaths,
+						List *resultRelations, List *subpaths,
 						List *subroots,
 						List *withCheckOptionLists, List *returningLists,
 						List *rowMarks, OnConflictExpr *onconflict,
-						List *mergeSourceTargetList,
-						List *mergeActionList, int epqParam);
+						int epqParam);
 extern LimitPath *create_limit_path(PlannerInfo *root, RelOptInfo *rel,
 				  Path *subpath,
 				  Node *limitOffset, Node *limitCount,

src/include/parser/analyze.h

@@ -32,11 +32,6 @@ extern Query *parse_sub_analyze(Node *parseTree, ParseState *parentParseState,
 				  bool locked_from_parent,
 				  bool resolve_unknowns);
 
-extern List *transformInsertRow(ParseState *pstate, List *exprlist,
-				   List *stmtcols, List *icolumns, List *attrnos,
-				   bool strip_indirection);
-extern List *transformUpdateTargetList(ParseState *pstate,
-						  List *targetList);
 extern Query *transformTopLevelStmt(ParseState *pstate, RawStmt *parseTree);
 extern Query *transformStmt(ParseState *pstate, Node *parseTree);
 

src/include/parser/kwlist.h

@@ -244,10 +244,8 @@ PG_KEYWORD("locked", LOCKED, UNRESERVED_KEYWORD)
 PG_KEYWORD("logged", LOGGED, UNRESERVED_KEYWORD)
 PG_KEYWORD("mapping", MAPPING, UNRESERVED_KEYWORD)
 PG_KEYWORD("match", MATCH, UNRESERVED_KEYWORD)
-PG_KEYWORD("matched", MATCHED, UNRESERVED_KEYWORD)
 PG_KEYWORD("materialized", MATERIALIZED, UNRESERVED_KEYWORD)
 PG_KEYWORD("maxvalue", MAXVALUE, UNRESERVED_KEYWORD)
-PG_KEYWORD("merge", MERGE, UNRESERVED_KEYWORD)
 PG_KEYWORD("method", METHOD, UNRESERVED_KEYWORD)
 PG_KEYWORD("minute", MINUTE_P, UNRESERVED_KEYWORD)
 PG_KEYWORD("minvalue", MINVALUE, UNRESERVED_KEYWORD)

src/include/parser/parse_clause.h

@@ -20,10 +20,7 @@ extern void transformFromClause(ParseState *pstate, List *frmList);
 extern int setTargetTable(ParseState *pstate, RangeVar *relation,
 			   bool inh, bool alsoSource, AclMode requiredPerms);
 extern bool interpretOidsOption(List *defList, bool allowOids);
-extern Node *transformFromClauseItem(ParseState *pstate, Node *n,
-						RangeTblEntry **top_rte, int *top_rti,
-						RangeTblEntry **right_rte, int *right_rti,
-						List **namespace);
+
 extern Node *transformWhereClause(ParseState *pstate, Node *clause,
 					 ParseExprKind exprKind, const char *constructName);
 extern Node *transformLimitClause(ParseState *pstate, Node *clause,

src/include/parser/parse_node.h

@@ -50,7 +50,6 @@ typedef enum ParseExprKind
 	EXPR_KIND_INSERT_TARGET,	/* INSERT target list item */
 	EXPR_KIND_UPDATE_SOURCE,	/* UPDATE assignment source item */
 	EXPR_KIND_UPDATE_TARGET,	/* UPDATE assignment target item */
-	EXPR_KIND_MERGE_WHEN_AND,	/* MERGE WHEN ... AND condition */
 	EXPR_KIND_GROUP_BY,			/* GROUP BY */
 	EXPR_KIND_ORDER_BY,			/* ORDER BY */
 	EXPR_KIND_DISTINCT_ON,		/* DISTINCT ON */
@@ -128,7 +127,7 @@ typedef Node *(*CoerceParamHook) (ParseState *pstate, Param *param,
  * p_parent_cte: CommonTableExpr that immediately contains the current query,
  * if any.
  *
- * p_target_relation: target relation, if query is INSERT/UPDATE/DELETE/MERGE
+ * p_target_relation: target relation, if query is INSERT, UPDATE, or DELETE.
  *
  * p_target_rangetblentry: target relation's entry in the rtable list.
  *
@@ -182,7 +181,7 @@ struct ParseState
 	List	   *p_ctenamespace; /* current namespace for common table exprs */
 	List	   *p_future_ctes;	/* common table exprs not yet in namespace */
 	CommonTableExpr *p_parent_cte;	/* this query's containing CTE */
-	Relation	p_target_relation;	/* INSERT/UPDATE/DELETE/MERGE target rel */
+	Relation	p_target_relation;	/* INSERT/UPDATE/DELETE target rel */
 	RangeTblEntry *p_target_rangetblentry;	/* target rel's RTE */
 	bool		p_is_insert;	/* process assignment like INSERT not UPDATE */
 	List	   *p_windowdefs;	/* raw representations of window clauses */

src/include/rewrite/rewriteHandler.h

@@ -25,7 +25,6 @@ extern void AcquireRewriteLocks(Query *parsetree,
 extern Node *build_column_default(Relation rel, int attrno);
 extern void rewriteTargetListUD(Query *parsetree, RangeTblEntry *target_rte,
 					Relation target_relation);
-extern void rewriteTargetListMerge(Query *parsetree, Relation target_relation);
 
 extern Query *get_view_query(Relation view);
 extern const char *view_query_is_auto_updatable(Query *viewquery,