Represent command completion tags as structs

The backend was using strings to represent command tags and doing string
comparisons in multiple places, but that's slow and unhelpful.  Create a
new command list with a supporting structure to use instead; this is
stored in a tag-list-file that can be tailored to specific purposes with
a caller-definable C macro, similar to what we do for WAL resource
managers.  The first first such uses are a new CommandTag enum and a
CommandTagBehavior struct.

Replace numerous occurrences of char *completionTag with a
QueryCompletion struct so that the code no longer stores information
about completed queries in a cstring.  Only at the last moment, in
EndCommand(), does this get converted to a string.

EventTriggerCacheItem no longer holds an array of palloc’d tag strings
in sorted order, but rather just a Bitmapset over the CommandTags.

Author: Mark Dilger, with unsolicited help from Álvaro Herrera
Reviewed-by: John Naylor, Tom Lane
Discussion: https://postgr.es/m/981A9DB4-3F0C-4DA5-88AD-CB9CFF4D6CAD@enterprisedb.com

6 files changed, 457 insertions, 380 deletions

diff --git a/src/backend/tcop/Makefile b/src/backend/tcop/Makefile
index c78f1e0a05e..f662a7dd1cf 100644
--- a/src/backend/tcop/Makefile
+++ b/src/backend/tcop/Makefile
@@ -13,6 +13,7 @@ top_builddir = ../../..
 include $(top_builddir)/src/Makefile.global
 
 OBJS = \
+	cmdtag.o \
 	dest.o \
 	fastpath.o \
 	postgres.o \
diff --git a/src/backend/tcop/cmdtag.c b/src/backend/tcop/cmdtag.c
new file mode 100644
index 00000000000..b9fbff612f2
--- /dev/null
+++ b/src/backend/tcop/cmdtag.c
@@ -0,0 +1,98 @@
+/*-------------------------------------------------------------------------
+ *
+ * cmdtag.c
+ *	  Data and routines for commandtag names and enumeration.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ *	  src/backend/tcop/cmdtag.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "miscadmin.h"
+#include "tcop/cmdtag.h"
+
+
+typedef struct CommandTagBehavior
+{
+	const char *name;
+	const bool	event_trigger_ok;
+	const bool	table_rewrite_ok;
+	const bool	display_rowcount;
+} CommandTagBehavior;
+
+#define PG_CMDTAG(tag, name, evtrgok, rwrok, rowcnt) \
+	{ name, evtrgok, rwrok, rowcnt },
+
+const CommandTagBehavior tag_behavior[COMMAND_TAG_NEXTTAG] = {
+#include "tcop/cmdtaglist.h"
+};
+
+#undef PG_CMDTAG
+
+void
+InitializeQueryCompletion(QueryCompletion *qc)
+{
+	qc->commandTag = CMDTAG_UNKNOWN;
+	qc->nprocessed = 0;
+}
+
+const char *
+GetCommandTagName(CommandTag commandTag)
+{
+	return tag_behavior[commandTag].name;
+}
+
+bool
+command_tag_display_rowcount(CommandTag commandTag)
+{
+	return tag_behavior[commandTag].display_rowcount;
+}
+
+bool
+command_tag_event_trigger_ok(CommandTag commandTag)
+{
+	return tag_behavior[commandTag].event_trigger_ok;
+}
+
+bool
+command_tag_table_rewrite_ok(CommandTag commandTag)
+{
+	return tag_behavior[commandTag].table_rewrite_ok;
+}
+
+/*
+ * Search CommandTag by name
+ *
+ * Returns CommandTag, or CMDTAG_UNKNOWN if not recognized
+ */
+CommandTag
+GetCommandTagEnum(const char *commandname)
+{
+	const CommandTagBehavior *base,
+			   *last,
+			   *position;
+	int			result;
+
+	if (commandname == NULL || *commandname == '\0')
+		return CMDTAG_UNKNOWN;
+
+	base = tag_behavior;
+	last = tag_behavior + lengthof(tag_behavior) - 1;
+	while (last >= base)
+	{
+		position = base + ((last - base) >> 1);
+		result = pg_strcasecmp(commandname, position->name);
+		if (result == 0)
+			return (CommandTag) (position - tag_behavior);
+		else if (result < 0)
+			last = position - 1;
+		else
+			base = position + 1;
+	}
+	return CMDTAG_UNKNOWN;
+}
diff --git a/src/backend/tcop/dest.c b/src/backend/tcop/dest.c
index 09c1dcbb537..7208751ec78 100644
--- a/src/backend/tcop/dest.c
+++ b/src/backend/tcop/dest.c
@@ -100,7 +100,7 @@ DestReceiver *None_Receiver = (DestReceiver *) &donothingDR;
  * ----------------
  */
 void
-BeginCommand(const char *commandTag, CommandDest dest)
+BeginCommand(CommandTag commandTag, CommandDest dest)
 {
 	/* Nothing to do at present */
 }
@@ -163,8 +163,12 @@ CreateDestReceiver(CommandDest dest)
  * ----------------
  */
 void
-EndCommand(const char *commandTag, CommandDest dest)
+EndCommand(const QueryCompletion *qc, CommandDest dest, bool force_undecorated_output)
 {
+	char		completionTag[COMPLETION_TAG_BUFSIZE];
+	CommandTag	tag;
+	const char *tagname;
+
 	switch (dest)
 	{
 		case DestRemote:
@@ -172,11 +176,27 @@ EndCommand(const char *commandTag, CommandDest dest)
 		case DestRemoteSimple:
 
 			/*
-			 * We assume the commandTag is plain ASCII and therefore requires
-			 * no encoding conversion.
+			 * We assume the tagname is plain ASCII and therefore requires no
+			 * encoding conversion.
+			 *
+			 * We no longer display LastOid, but to preserve the wire
+			 * protocol, we write InvalidOid where the LastOid used to be
+			 * written.
+			 *
+			 * All cases where LastOid was written also write nprocessed
+			 * count, so just Assert that rather than having an extra test.
 			 */
-			pq_putmessage('C', commandTag, strlen(commandTag) + 1);
-			break;
+			tag = qc->commandTag;
+			tagname = GetCommandTagName(tag);
+
+			if (command_tag_display_rowcount(tag) && !force_undecorated_output)
+				snprintf(completionTag, COMPLETION_TAG_BUFSIZE,
+						 tag == CMDTAG_INSERT ?
+						 "%s 0 " UINT64_FORMAT : "%s " UINT64_FORMAT,
+						 tagname, qc->nprocessed);
+			else
+				snprintf(completionTag, COMPLETION_TAG_BUFSIZE, "%s", tagname);
+			pq_putmessage('C', completionTag, strlen(completionTag) + 1);
 
 		case DestNone:
 		case DestDebug:
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 23661ae15f5..9dba3b0566a 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -1064,8 +1064,8 @@ exec_simple_query(const char *query_string)
 	{
 		RawStmt    *parsetree = lfirst_node(RawStmt, parsetree_item);
 		bool		snapshot_set = false;
-		const char *commandTag;
-		char		completionTag[COMPLETION_TAG_BUFSIZE];
+		CommandTag	commandTag;
+		QueryCompletion qc;
 		MemoryContext per_parsetree_context = NULL;
 		List	   *querytree_list,
 				   *plantree_list;
@@ -1081,7 +1081,7 @@ exec_simple_query(const char *query_string)
 		 */
 		commandTag = CreateCommandTag(parsetree->stmt);
 
-		set_ps_display(commandTag, false);
+		set_ps_display(GetCommandTagName(commandTag), false);
 
 		BeginCommand(commandTag, dest);
 
@@ -1239,7 +1239,7 @@ exec_simple_query(const char *query_string)
 						 true,
 						 receiver,
 						 receiver,
-						 completionTag);
+						 &qc);
 
 		receiver->rDestroy(receiver);
 
@@ -1290,7 +1290,7 @@ exec_simple_query(const char *query_string)
 		 * command the client sent, regardless of rewriting. (But a command
 		 * aborted by error will not send an EndCommand report at all.)
 		 */
-		EndCommand(completionTag, dest);
+		EndCommand(&qc, dest, false);
 
 		/* Now we may drop the per-parsetree context, if one was created. */
 		if (per_parsetree_context)
@@ -1352,7 +1352,6 @@ exec_parse_message(const char *query_string,	/* string to execute */
 	MemoryContext oldcontext;
 	List	   *parsetree_list;
 	RawStmt    *raw_parse_tree;
-	const char *commandTag;
 	List	   *querytree_list;
 	CachedPlanSource *psrc;
 	bool		is_named;
@@ -1439,11 +1438,6 @@ exec_parse_message(const char *query_string,	/* string to execute */
 		raw_parse_tree = linitial_node(RawStmt, parsetree_list);
 
 		/*
-		 * Get the command name for possible use in status display.
-		 */
-		commandTag = CreateCommandTag(raw_parse_tree->stmt);
-
-		/*
 		 * If we are in an aborted transaction, reject all commands except
 		 * COMMIT/ROLLBACK.  It is important that this test occur before we
 		 * try to do parse analysis, rewrite, or planning, since all those
@@ -1463,7 +1457,8 @@ exec_parse_message(const char *query_string,	/* string to execute */
 		 * Create the CachedPlanSource before we do parse analysis, since it
 		 * needs to see the unmodified raw parse tree.
 		 */
-		psrc = CreateCachedPlan(raw_parse_tree, query_string, commandTag);
+		psrc = CreateCachedPlan(raw_parse_tree, query_string,
+								CreateCommandTag(raw_parse_tree->stmt));
 
 		/*
 		 * Set up a snapshot if parse analysis will need one.
@@ -1514,8 +1509,8 @@ exec_parse_message(const char *query_string,	/* string to execute */
 	{
 		/* Empty input string.  This is legal. */
 		raw_parse_tree = NULL;
-		commandTag = NULL;
-		psrc = CreateCachedPlan(raw_parse_tree, query_string, commandTag);
+		psrc = CreateCachedPlan(raw_parse_tree, query_string,
+								CMDTAG_UNKNOWN);
 		querytree_list = NIL;
 	}
 
@@ -2031,7 +2026,7 @@ exec_execute_message(const char *portal_name, long max_rows)
 	DestReceiver *receiver;
 	Portal		portal;
 	bool		completed;
-	char		completionTag[COMPLETION_TAG_BUFSIZE];
+	QueryCompletion qc;
 	const char *sourceText;
 	const char *prepStmtName;
 	ParamListInfo portalParams;
@@ -2058,7 +2053,7 @@ exec_execute_message(const char *portal_name, long max_rows)
 	 * If the original query was a null string, just return
 	 * EmptyQueryResponse.
 	 */
-	if (portal->commandTag == NULL)
+	if (portal->commandTag == CMDTAG_UNKNOWN)
 	{
 		Assert(portal->stmts == NIL);
 		NullCommand(dest);
@@ -2104,7 +2099,7 @@ exec_execute_message(const char *portal_name, long max_rows)
 
 	pgstat_report_activity(STATE_RUNNING, sourceText);
 
-	set_ps_display(portal->commandTag, false);
+	set_ps_display(GetCommandTagName(portal->commandTag), false);
 
 	if (save_log_statement_stats)
 		ResetUsage();
@@ -2185,7 +2180,7 @@ exec_execute_message(const char *portal_name, long max_rows)
 						  !execute_is_fetch && max_rows == FETCH_ALL,
 						  receiver,
 						  receiver,
-						  completionTag);
+						  &qc);
 
 	receiver->rDestroy(receiver);
 
@@ -2218,7 +2213,7 @@ exec_execute_message(const char *portal_name, long max_rows)
 		}
 
 		/* Send appropriate CommandComplete to client */
-		EndCommand(completionTag, dest);
+		EndCommand(&qc, dest, false);
 	}
 	else
 	{
diff --git a/src/backend/tcop/pquery.c b/src/backend/tcop/pquery.c
index 0f5801e0460..5781fb2e55c 100644
--- a/src/backend/tcop/pquery.c
+++ b/src/backend/tcop/pquery.c
@@ -40,7 +40,7 @@ static void ProcessQuery(PlannedStmt *plan,
 						 ParamListInfo params,
 						 QueryEnvironment *queryEnv,
 						 DestReceiver *dest,
-						 char *completionTag);
+						 QueryCompletion *qc);
 static void FillPortalStore(Portal portal, bool isTopLevel);
 static uint64 RunFromStore(Portal portal, ScanDirection direction, uint64 count,
 						   DestReceiver *dest);
@@ -48,11 +48,11 @@ static uint64 PortalRunSelect(Portal portal, bool forward, long count,
 							  DestReceiver *dest);
 static void PortalRunUtility(Portal portal, PlannedStmt *pstmt,
 							 bool isTopLevel, bool setHoldSnapshot,
-							 DestReceiver *dest, char *completionTag);
+							 DestReceiver *dest, QueryCompletion *qc);
 static void PortalRunMulti(Portal portal,
 						   bool isTopLevel, bool setHoldSnapshot,
 						   DestReceiver *dest, DestReceiver *altdest,
-						   char *completionTag);
+						   QueryCompletion *qc);
 static uint64 DoPortalRunFetch(Portal portal,
 							   FetchDirection fdirection,
 							   long count,
@@ -125,10 +125,9 @@ FreeQueryDesc(QueryDesc *qdesc)
  *	sourceText: the source text of the query
  *	params: any parameters needed
  *	dest: where to send results
- *	completionTag: points to a buffer of size COMPLETION_TAG_BUFSIZE
- *		in which to store a command completion status string.
+ *	qc: where to store the command completion status data.
  *
- * completionTag may be NULL if caller doesn't want a status string.
+ * qc may be NULL if caller doesn't want a status string.
  *
  * Must be called in a memory context that will be reset or deleted on
  * error; otherwise the executor's memory usage will be leaked.
@@ -139,7 +138,7 @@ ProcessQuery(PlannedStmt *plan,
 			 ParamListInfo params,
 			 QueryEnvironment *queryEnv,
 			 DestReceiver *dest,
-			 char *completionTag)
+			 QueryCompletion *qc)
 {
 	QueryDesc  *queryDesc;
 
@@ -161,38 +160,26 @@ ProcessQuery(PlannedStmt *plan,
 	ExecutorRun(queryDesc, ForwardScanDirection, 0L, true);
 
 	/*
-	 * Build command completion status string, if caller wants one.
+	 * Build command completion status data, if caller wants one.
 	 */
-	if (completionTag)
+	if (qc)
 	{
-		Oid			lastOid;
-
 		switch (queryDesc->operation)
 		{
 			case CMD_SELECT:
-				snprintf(completionTag, COMPLETION_TAG_BUFSIZE,
-						 "SELECT " UINT64_FORMAT,
-						 queryDesc->estate->es_processed);
+				SetQueryCompletion(qc, CMDTAG_SELECT, queryDesc->estate->es_processed);
 				break;
 			case CMD_INSERT:
-				/* lastoid doesn't exist anymore */
-				lastOid = InvalidOid;
-				snprintf(completionTag, COMPLETION_TAG_BUFSIZE,
-						 "INSERT %u " UINT64_FORMAT,
-						 lastOid, queryDesc->estate->es_processed);
+				SetQueryCompletion(qc, CMDTAG_INSERT, queryDesc->estate->es_processed);
 				break;
 			case CMD_UPDATE:
-				snprintf(completionTag, COMPLETION_TAG_BUFSIZE,
-						 "UPDATE " UINT64_FORMAT,
-						 queryDesc->estate->es_processed);
+				SetQueryCompletion(qc, CMDTAG_UPDATE, queryDesc->estate->es_processed);
 				break;
 			case CMD_DELETE:
-				snprintf(completionTag, COMPLETION_TAG_BUFSIZE,
-						 "DELETE " UINT64_FORMAT,
-						 queryDesc->estate->es_processed);
+				SetQueryCompletion(qc, CMDTAG_DELETE, queryDesc->estate->es_processed);
 				break;
 			default:
-				strcpy(completionTag, "???");
+				SetQueryCompletion(qc, CMDTAG_UNKNOWN, queryDesc->estate->es_processed);
 				break;
 		}
 	}
@@ -675,9 +662,8 @@ PortalSetResultFormat(Portal portal, int nFormats, int16 *formats)
  *
  * altdest: where to send output of non-primary queries
  *
- * completionTag: points to a buffer of size COMPLETION_TAG_BUFSIZE
- *		in which to store a command completion status string.
- *		May be NULL if caller doesn't want a status string.
+ * qc: where to store command completion status data.
+ *		May be NULL if caller doesn't want status data.
  *
  * Returns true if the portal's execution is complete, false if it was
  * suspended due to exhaustion of the count parameter.
@@ -685,7 +671,7 @@ PortalSetResultFormat(Portal portal, int nFormats, int16 *formats)
 bool
 PortalRun(Portal portal, long count, bool isTopLevel, bool run_once,
 		  DestReceiver *dest, DestReceiver *altdest,
-		  char *completionTag)
+		  QueryCompletion *qc)
 {
 	bool		result;
 	uint64		nprocessed;
@@ -700,9 +686,9 @@ PortalRun(Portal portal, long count, bool isTopLevel, bool run_once,
 
 	TRACE_POSTGRESQL_QUERY_EXECUTE_START();
 
-	/* Initialize completion tag to empty string */
-	if (completionTag)
-		completionTag[0] = '\0';
+	/* Initialize empty completion data */
+	if (qc)
+		InitializeQueryCompletion(qc);
 
 	if (log_executor_stats && portal->strategy != PORTAL_MULTI_QUERY)
 	{
@@ -771,16 +757,13 @@ PortalRun(Portal portal, long count, bool isTopLevel, bool run_once,
 
 				/*
 				 * If the portal result contains a command tag and the caller
-				 * gave us a pointer to store it, copy it. Patch the "SELECT"
-				 * tag to also provide the rowcount.
+				 * gave us a pointer to store it, copy it and update the
+				 * rowcount.
 				 */
-				if (completionTag && portal->commandTag)
+				if (qc && portal->qc.commandTag != CMDTAG_UNKNOWN)
 				{
-					if (strcmp(portal->commandTag, "SELECT") == 0)
-						snprintf(completionTag, COMPLETION_TAG_BUFSIZE,
-								 "SELECT " UINT64_FORMAT, nprocessed);
-					else
-						strcpy(completionTag, portal->commandTag);
+					CopyQueryCompletion(qc, &portal->qc);
+					qc->nprocessed = nprocessed;
 				}
 
 				/* Mark portal not active */
@@ -794,7 +777,7 @@ PortalRun(Portal portal, long count, bool isTopLevel, bool run_once,
 
 			case PORTAL_MULTI_QUERY:
 				PortalRunMulti(portal, isTopLevel, false,
-							   dest, altdest, completionTag);
+							   dest, altdest, qc);
 
 				/* Prevent portal's commands from being re-executed */
 				MarkPortalDone(portal);
@@ -1005,8 +988,9 @@ static void
 FillPortalStore(Portal portal, bool isTopLevel)
 {
 	DestReceiver *treceiver;
-	char		completionTag[COMPLETION_TAG_BUFSIZE];
+	QueryCompletion qc;
 
+	InitializeQueryCompletion(&qc);
 	PortalCreateHoldStore(portal);
 	treceiver = CreateDestReceiver(DestTuplestore);
 	SetTuplestoreDestReceiverParams(treceiver,
@@ -1014,8 +998,6 @@ FillPortalStore(Portal portal, bool isTopLevel)
 									portal->holdContext,
 									false);
 
-	completionTag[0] = '\0';
-
 	switch (portal->strategy)
 	{
 		case PORTAL_ONE_RETURNING:
@@ -1028,12 +1010,12 @@ FillPortalStore(Portal portal, bool isTopLevel)
 			 * portal's holdSnapshot to the snapshot used (or a copy of it).
 			 */
 			PortalRunMulti(portal, isTopLevel, true,
-						   treceiver, None_Receiver, completionTag);
+						   treceiver, None_Receiver, &qc);
 			break;
 
 		case PORTAL_UTIL_SELECT:
 			PortalRunUtility(portal, linitial_node(PlannedStmt, portal->stmts),
-							 isTopLevel, true, treceiver, completionTag);
+							 isTopLevel, true, treceiver, &qc);
 			break;
 
 		default:
@@ -1042,9 +1024,9 @@ FillPortalStore(Portal portal, bool isTopLevel)
 			break;
 	}
 
-	/* Override default completion tag with actual command result */
-	if (completionTag[0] != '\0')
-		portal->commandTag = pstrdup(completionTag);
+	/* Override portal completion data with actual command results */
+	if (qc.commandTag != CMDTAG_UNKNOWN)
+		CopyQueryCompletion(&portal->qc, &qc);
 
 	treceiver->rDestroy(treceiver);
 }
@@ -1130,7 +1112,7 @@ RunFromStore(Portal portal, ScanDirection direction, uint64 count,
 static void
 PortalRunUtility(Portal portal, PlannedStmt *pstmt,
 				 bool isTopLevel, bool setHoldSnapshot,
-				 DestReceiver *dest, char *completionTag)
+				 DestReceiver *dest, QueryCompletion *qc)
 {
 	Node	   *utilityStmt = pstmt->utilityStmt;
 	Snapshot	snapshot;
@@ -1178,7 +1160,7 @@ PortalRunUtility(Portal portal, PlannedStmt *pstmt,
 				   portal->portalParams,
 				   portal->queryEnv,
 				   dest,
-				   completionTag);
+				   qc);
 
 	/* Some utility statements may change context on us */
 	MemoryContextSwitchTo(portal->portalContext);
@@ -1202,7 +1184,7 @@ static void
 PortalRunMulti(Portal portal,
 			   bool isTopLevel, bool setHoldSnapshot,
 			   DestReceiver *dest, DestReceiver *altdest,
-			   char *completionTag)
+			   QueryCompletion *qc)
 {
 	bool		active_snapshot_set = false;
 	ListCell   *stmtlist_item;
@@ -1284,7 +1266,7 @@ PortalRunMulti(Portal portal,
 							 portal->sourceText,
 							 portal->portalParams,
 							 portal->queryEnv,
-							 dest, completionTag);
+							 dest, qc);
 			}
 			else
 			{
@@ -1319,7 +1301,7 @@ PortalRunMulti(Portal portal,
 				Assert(!active_snapshot_set);
 				/* statement can set tag string */
 				PortalRunUtility(portal, pstmt, isTopLevel, false,
-								 dest, completionTag);
+								 dest, qc);
 			}
 			else
 			{
@@ -1350,8 +1332,8 @@ PortalRunMulti(Portal portal,
 		PopActiveSnapshot();
 
 	/*
-	 * If a command completion tag was supplied, use it.  Otherwise use the
-	 * portal's commandTag as the default completion tag.
+	 * If a query completion data was supplied, use it.  Otherwise use the
+	 * portal's query completion data.
 	 *
 	 * Exception: Clients expect INSERT/UPDATE/DELETE tags to have counts, so
 	 * fake them with zeros.  This can happen with DO INSTEAD rules if there
@@ -1361,18 +1343,12 @@ PortalRunMulti(Portal portal,
 	 * e.g.  an INSERT that does an UPDATE instead should not print "0 1" if
 	 * one row was updated.  See QueryRewrite(), step 3, for details.
 	 */
-	if (completionTag && completionTag[0] == '\0')
+	if (qc && qc->commandTag == CMDTAG_UNKNOWN)
 	{
-		if (portal->commandTag)
-			strcpy(completionTag, portal->commandTag);
-		if (strcmp(completionTag, "SELECT") == 0)
-			sprintf(completionTag, "SELECT 0 0");
-		else if (strcmp(completionTag, "INSERT") == 0)
-			strcpy(completionTag, "INSERT 0 0");
-		else if (strcmp(completionTag, "UPDATE") == 0)
-			strcpy(completionTag, "UPDATE 0");
-		else if (strcmp(completionTag, "DELETE") == 0)
-			strcpy(completionTag, "DELETE 0");
+		if (portal->qc.commandTag != CMDTAG_UNKNOWN)
+			CopyQueryCompletion(qc, &portal->qc);
+		/* If the caller supplied a qc, we should have set it by now. */
+		Assert(qc->commandTag != CMDTAG_UNKNOWN);
 	}
 }
 
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index bb85b5e52aa..1b460a26126 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -75,7 +75,7 @@
 ProcessUtility_hook_type ProcessUtility_hook = NULL;
 
 /* local function declarations */
-static int ClassifyUtilityCommandAsReadOnly(Node *parsetree);
+static int	ClassifyUtilityCommandAsReadOnly(Node *parsetree);
 static void ProcessUtilitySlow(ParseState *pstate,
 							   PlannedStmt *pstmt,
 							   const char *queryString,
@@ -83,10 +83,9 @@ static void ProcessUtilitySlow(ParseState *pstate,
 							   ParamListInfo params,
 							   QueryEnvironment *queryEnv,
 							   DestReceiver *dest,
-							   char *completionTag);
+							   QueryCompletion *qc);
 static void ExecDropStmt(DropStmt *stmt, bool isTopLevel);
 
-
 /*
  * CommandIsReadOnly: is an executable query read-only?
  *
@@ -467,7 +466,6 @@ CheckRestrictedOperation(const char *cmdname)
 						cmdname)));
 }
 
-
 /*
  * ProcessUtility
  *		general utility function invoker
@@ -480,17 +478,13 @@ CheckRestrictedOperation(const char *cmdname)
  *	queryEnv: environment for parse through execution (e.g., ephemeral named
  *		tables like trigger transition tables).  May be NULL.
  *	dest: where to send results
- *	completionTag: points to a buffer of size COMPLETION_TAG_BUFSIZE
- *		in which to store a command completion status string.
+ *	qc: where to store command completion status data.  May be NULL,
+ *		but if not, then caller must have initialized it.
  *
  * Caller MUST supply a queryString; it is not allowed (anymore) to pass NULL.
  * If you really don't have source text, you can pass a constant string,
  * perhaps "(query not available)".
  *
- * completionTag is only set nonempty if we want to return a nondefault status.
- *
- * completionTag may be NULL if caller doesn't want a status string.
- *
  * Note for users of ProcessUtility_hook: the same queryString may be passed
  * to multiple invocations of ProcessUtility when processing a query string
  * containing multiple semicolon-separated statements.  One should use
@@ -507,11 +501,12 @@ ProcessUtility(PlannedStmt *pstmt,
 			   ParamListInfo params,
 			   QueryEnvironment *queryEnv,
 			   DestReceiver *dest,
-			   char *completionTag)
+			   QueryCompletion *qc)
 {
 	Assert(IsA(pstmt, PlannedStmt));
 	Assert(pstmt->commandType == CMD_UTILITY);
 	Assert(queryString != NULL);	/* required as of 8.4 */
+	Assert(qc == NULL || qc->commandTag == CMDTAG_UNKNOWN);
 
 	/*
 	 * We provide a function hook variable that lets loadable plugins get
@@ -521,11 +516,11 @@ ProcessUtility(PlannedStmt *pstmt,
 	if (ProcessUtility_hook)
 		(*ProcessUtility_hook) (pstmt, queryString,
 								context, params, queryEnv,
-								dest, completionTag);
+								dest, qc);
 	else
 		standard_ProcessUtility(pstmt, queryString,
 								context, params, queryEnv,
-								dest, completionTag);
+								dest, qc);
 }
 
 /*
@@ -546,7 +541,7 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 						ParamListInfo params,
 						QueryEnvironment *queryEnv,
 						DestReceiver *dest,
-						char *completionTag)
+						QueryCompletion *qc)
 {
 	Node	   *parsetree = pstmt->utilityStmt;
 	bool		isTopLevel = (context == PROCESS_UTILITY_TOPLEVEL);
@@ -562,19 +557,16 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 	if (readonly_flags != COMMAND_IS_STRICTLY_READ_ONLY &&
 		(XactReadOnly || IsInParallelMode()))
 	{
-		const char *commandtag = CreateCommandTag(parsetree);
+		CommandTag	commandtag = CreateCommandTag(parsetree);
 
 		if ((readonly_flags & COMMAND_OK_IN_READ_ONLY_TXN) == 0)
-			PreventCommandIfReadOnly(commandtag);
+			PreventCommandIfReadOnly(GetCommandTagName(commandtag));
 		if ((readonly_flags & COMMAND_OK_IN_PARALLEL_MODE) == 0)
-			PreventCommandIfParallelMode(commandtag);
+			PreventCommandIfParallelMode(GetCommandTagName(commandtag));
 		if ((readonly_flags & COMMAND_OK_IN_RECOVERY) == 0)
-			PreventCommandDuringRecovery(commandtag);
+			PreventCommandDuringRecovery(GetCommandTagName(commandtag));
 	}
 
-	if (completionTag)
-		completionTag[0] = '\0';
-
 	pstate = make_parsestate(NULL);
 	pstate->p_sourcetext = queryString;
 	pstate->p_queryEnv = queryEnv;
@@ -623,18 +615,18 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 					case TRANS_STMT_COMMIT:
 						if (!EndTransactionBlock(stmt->chain))
 						{
-							/* report unsuccessful commit in completionTag */
-							if (completionTag)
-								strcpy(completionTag, "ROLLBACK");
+							/* report unsuccessful commit in qc */
+							if (qc)
+								SetQueryCompletion(qc, CMDTAG_ROLLBACK, 0);
 						}
 						break;
 
 					case TRANS_STMT_PREPARE:
 						if (!PrepareTransactionBlock(stmt->gid))
 						{
-							/* report unsuccessful commit in completionTag */
-							if (completionTag)
-								strcpy(completionTag, "ROLLBACK");
+							/* report unsuccessful commit in qc */
+							if (qc)
+								SetQueryCompletion(qc, CMDTAG_ROLLBACK, 0);
 						}
 						break;
 
@@ -693,8 +685,7 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 			break;
 
 		case T_FetchStmt:
-			PerformPortalFetch((FetchStmt *) parsetree, dest,
-							   completionTag);
+			PerformPortalFetch((FetchStmt *) parsetree, dest, qc);
 			break;
 
 		case T_DoStmt:
@@ -729,9 +720,8 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 				DoCopy(pstate, (CopyStmt *) parsetree,
 					   pstmt->stmt_location, pstmt->stmt_len,
 					   &processed);
-				if (completionTag)
-					snprintf(completionTag, COMPLETION_TAG_BUFSIZE,
-							 "COPY " UINT64_FORMAT, processed);
+				if (qc)
+					SetQueryCompletion(qc, CMDTAG_COPY, processed);
 			}
 			break;
 
@@ -745,7 +735,7 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 			ExecuteQuery(pstate,
 						 (ExecuteStmt *) parsetree, NULL,
 						 params,
-						 dest, completionTag);
+						 dest, qc);
 			break;
 
 		case T_DeallocateStmt:
@@ -974,7 +964,7 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 				if (EventTriggerSupportsObjectType(stmt->objtype))
 					ProcessUtilitySlow(pstate, pstmt, queryString,
 									   context, params, queryEnv,
-									   dest, completionTag);
+									   dest, qc);
 				else
 					ExecuteGrantStmt(stmt);
 			}
@@ -987,7 +977,7 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 				if (EventTriggerSupportsObjectType(stmt->removeType))
 					ProcessUtilitySlow(pstate, pstmt, queryString,
 									   context, params, queryEnv,
-									   dest, completionTag);
+									   dest, qc);
 				else
 					ExecDropStmt(stmt, isTopLevel);
 			}
@@ -1000,7 +990,7 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 				if (EventTriggerSupportsObjectType(stmt->renameType))
 					ProcessUtilitySlow(pstate, pstmt, queryString,
 									   context, params, queryEnv,
-									   dest, completionTag);
+									   dest, qc);
 				else
 					ExecRenameStmt(stmt);
 			}
@@ -1013,7 +1003,7 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 				if (EventTriggerSupportsObjectType(stmt->objectType))
 					ProcessUtilitySlow(pstate, pstmt, queryString,
 									   context, params, queryEnv,
-									   dest, completionTag);
+									   dest, qc);
 				else
 					ExecAlterObjectDependsStmt(stmt, NULL);
 			}
@@ -1026,7 +1016,7 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 				if (EventTriggerSupportsObjectType(stmt->objectType))
 					ProcessUtilitySlow(pstate, pstmt, queryString,
 									   context, params, queryEnv,
-									   dest, completionTag);
+									   dest, qc);
 				else
 					ExecAlterObjectSchemaStmt(stmt, NULL);
 			}
@@ -1039,7 +1029,7 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 				if (EventTriggerSupportsObjectType(stmt->objectType))
 					ProcessUtilitySlow(pstate, pstmt, queryString,
 									   context, params, queryEnv,
-									   dest, completionTag);
+									   dest, qc);
 				else
 					ExecAlterOwnerStmt(stmt);
 			}
@@ -1052,7 +1042,7 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 				if (EventTriggerSupportsObjectType(stmt->objtype))
 					ProcessUtilitySlow(pstate, pstmt, queryString,
 									   context, params, queryEnv,
-									   dest, completionTag);
+									   dest, qc);
 				else
 					CommentObject(stmt);
 				break;
@@ -1065,7 +1055,7 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 				if (EventTriggerSupportsObjectType(stmt->objtype))
 					ProcessUtilitySlow(pstate, pstmt, queryString,
 									   context, params, queryEnv,
-									   dest, completionTag);
+									   dest, qc);
 				else
 					ExecSecLabelStmt(stmt);
 				break;
@@ -1075,7 +1065,7 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 			/* All other statement types have event trigger support */
 			ProcessUtilitySlow(pstate, pstmt, queryString,
 							   context, params, queryEnv,
-							   dest, completionTag);
+							   dest, qc);
 			break;
 	}
 
@@ -1102,7 +1092,7 @@ ProcessUtilitySlow(ParseState *pstate,
 				   ParamListInfo params,
 				   QueryEnvironment *queryEnv,
 				   DestReceiver *dest,
-				   char *completionTag)
+				   QueryCompletion *qc)
 {
 	Node	   *parsetree = pstmt->utilityStmt;
 	bool		isTopLevel = (context == PROCESS_UTILITY_TOPLEVEL);
@@ -1605,7 +1595,7 @@ ProcessUtilitySlow(ParseState *pstate,
 
 			case T_CreateTableAsStmt:
 				address = ExecCreateTableAs(pstate, (CreateTableAsStmt *) parsetree,
-											params, queryEnv, completionTag);
+											params, queryEnv, qc);
 				break;
 
 			case T_RefreshMatViewStmt:
@@ -1620,7 +1610,7 @@ ProcessUtilitySlow(ParseState *pstate,
 				PG_TRY();
 				{
 					address = ExecRefreshMatView((RefreshMatViewStmt *) parsetree,
-												 queryString, params, completionTag);
+												 queryString, params, qc);
 				}
 				PG_FINALLY();
 				{
@@ -2099,137 +2089,137 @@ UtilityContainsQuery(Node *parsetree)
  *
  * This covers most cases where ALTER is used with an ObjectType enum.
  */
-static const char *
+static CommandTag
 AlterObjectTypeCommandTag(ObjectType objtype)
 {
-	const char *tag;
+	CommandTag	tag;
 
 	switch (objtype)
 	{
 		case OBJECT_AGGREGATE:
-			tag = "ALTER AGGREGATE";
+			tag = CMDTAG_ALTER_AGGREGATE;
 			break;
 		case OBJECT_ATTRIBUTE:
-			tag = "ALTER TYPE";
+			tag = CMDTAG_ALTER_TYPE;
 			break;
 		case OBJECT_CAST:
-			tag = "ALTER CAST";
+			tag = CMDTAG_ALTER_CAST;
 			break;
 		case OBJECT_COLLATION:
-			tag = "ALTER COLLATION";
+			tag = CMDTAG_ALTER_COLLATION;
 			break;
 		case OBJECT_COLUMN:
-			tag = "ALTER TABLE";
+			tag = CMDTAG_ALTER_TABLE;
 			break;
 		case OBJECT_CONVERSION:
-			tag = "ALTER CONVERSION";
+			tag = CMDTAG_ALTER_CONVERSION;
 			break;
 		case OBJECT_DATABASE:
-			tag = "ALTER DATABASE";
+			tag = CMDTAG_ALTER_DATABASE;
 			break;
 		case OBJECT_DOMAIN:
 		case OBJECT_DOMCONSTRAINT:
-			tag = "ALTER DOMAIN";
+			tag = CMDTAG_ALTER_DOMAIN;
 			break;
 		case OBJECT_EXTENSION:
-			tag = "ALTER EXTENSION";
+			tag = CMDTAG_ALTER_EXTENSION;
 			break;
 		case OBJECT_FDW:
-			tag = "ALTER FOREIGN DATA WRAPPER";
+			tag = CMDTAG_ALTER_FOREIGN_DATA_WRAPPER;
 			break;
 		case OBJECT_FOREIGN_SERVER:
-			tag = "ALTER SERVER";
+			tag = CMDTAG_ALTER_SERVER;
 			break;
 		case OBJECT_FOREIGN_TABLE:
-			tag = "ALTER FOREIGN TABLE";
+			tag = CMDTAG_ALTER_FOREIGN_TABLE;
 			break;
 		case OBJECT_FUNCTION:
-			tag = "ALTER FUNCTION";
+			tag = CMDTAG_ALTER_FUNCTION;
 			break;
 		case OBJECT_INDEX:
-			tag = "ALTER INDEX";
+			tag = CMDTAG_ALTER_INDEX;
 			break;
 		case OBJECT_LANGUAGE:
-			tag = "ALTER LANGUAGE";
+			tag = CMDTAG_ALTER_LANGUAGE;
 			break;
 		case OBJECT_LARGEOBJECT:
-			tag = "ALTER LARGE OBJECT";
+			tag = CMDTAG_ALTER_LARGE_OBJECT;
 			break;
 		case OBJECT_OPCLASS:
-			tag = "ALTER OPERATOR CLASS";
+			tag = CMDTAG_ALTER_OPERATOR_CLASS;
 			break;
 		case OBJECT_OPERATOR:
-			tag = "ALTER OPERATOR";
+			tag = CMDTAG_ALTER_OPERATOR;
 			break;
 		case OBJECT_OPFAMILY:
-			tag = "ALTER OPERATOR FAMILY";
+			tag = CMDTAG_ALTER_OPERATOR_FAMILY;
 			break;
 		case OBJECT_POLICY:
-			tag = "ALTER POLICY";
+			tag = CMDTAG_ALTER_POLICY;
 			break;
 		case OBJECT_PROCEDURE:
-			tag = "ALTER PROCEDURE";
+			tag = CMDTAG_ALTER_PROCEDURE;
 			break;
 		case OBJECT_ROLE:
-			tag = "ALTER ROLE";
+			tag = CMDTAG_ALTER_ROLE;
 			break;
 		case OBJECT_ROUTINE:
-			tag = "ALTER ROUTINE";
+			tag = CMDTAG_ALTER_ROUTINE;
 			break;
 		case OBJECT_RULE:
-			tag = "ALTER RULE";
+			tag = CMDTAG_ALTER_RULE;
 			break;
 		case OBJECT_SCHEMA:
-			tag = "ALTER SCHEMA";
+			tag = CMDTAG_ALTER_SCHEMA;
 			break;
 		case OBJECT_SEQUENCE:
-			tag = "ALTER SEQUENCE";
+			tag = CMDTAG_ALTER_SEQUENCE;
 			break;
 		case OBJECT_TABLE:
 		case OBJECT_TABCONSTRAINT:
-			tag = "ALTER TABLE";
+			tag = CMDTAG_ALTER_TABLE;
 			break;
 		case OBJECT_TABLESPACE:
-			tag = "ALTER TABLESPACE";
+			tag = CMDTAG_ALTER_TABLESPACE;
 			break;
 		case OBJECT_TRIGGER:
-			tag = "ALTER TRIGGER";
+			tag = CMDTAG_ALTER_TRIGGER;
 			break;
 		case OBJECT_EVENT_TRIGGER:
-			tag = "ALTER EVENT TRIGGER";
+			tag = CMDTAG_ALTER_EVENT_TRIGGER;
 			break;
 		case OBJECT_TSCONFIGURATION:
-			tag = "ALTER TEXT SEARCH CONFIGURATION";
+			tag = CMDTAG_ALTER_TEXT_SEARCH_CONFIGURATION;
 			break;
 		case OBJECT_TSDICTIONARY:
-			tag = "ALTER TEXT SEARCH DICTIONARY";
+			tag = CMDTAG_ALTER_TEXT_SEARCH_DICTIONARY;
 			break;
 		case OBJECT_TSPARSER:
-			tag = "ALTER TEXT SEARCH PARSER";
+			tag = CMDTAG_ALTER_TEXT_SEARCH_PARSER;
 			break;
 		case OBJECT_TSTEMPLATE:
-			tag = "ALTER TEXT SEARCH TEMPLATE";
+			tag = CMDTAG_ALTER_TEXT_SEARCH_TEMPLATE;
 			break;
 		case OBJECT_TYPE:
-			tag = "ALTER TYPE";
+			tag = CMDTAG_ALTER_TYPE;
 			break;
 		case OBJECT_VIEW:
-			tag = "ALTER VIEW";
+			tag = CMDTAG_ALTER_VIEW;
 			break;
 		case OBJECT_MATVIEW:
-			tag = "ALTER MATERIALIZED VIEW";
+			tag = CMDTAG_ALTER_MATERIALIZED_VIEW;
 			break;
 		case OBJECT_PUBLICATION:
-			tag = "ALTER PUBLICATION";
+			tag = CMDTAG_ALTER_PUBLICATION;
 			break;
 		case OBJECT_SUBSCRIPTION:
-			tag = "ALTER SUBSCRIPTION";
+			tag = CMDTAG_ALTER_SUBSCRIPTION;
 			break;
 		case OBJECT_STATISTIC_EXT:
-			tag = "ALTER STATISTICS";
+			tag = CMDTAG_ALTER_STATISTICS;
 			break;
 		default:
-			tag = "???";
+			tag = CMDTAG_UNKNOWN;
 			break;
 	}
 
@@ -2238,20 +2228,17 @@ AlterObjectTypeCommandTag(ObjectType objtype)
 
 /*
  * CreateCommandTag
- *		utility to get a string representation of the command operation,
+ *		utility to get a CommandTag for the command operation,
  *		given either a raw (un-analyzed) parsetree, an analyzed Query,
  *		or a PlannedStmt.
  *
  * This must handle all command types, but since the vast majority
  * of 'em are utility commands, it seems sensible to keep it here.
- *
- * NB: all result strings must be shorter than COMPLETION_TAG_BUFSIZE.
- * Also, the result must point at a true constant (permanent storage).
  */
-const char *
+CommandTag
 CreateCommandTag(Node *parsetree)
 {
-	const char *tag;
+	CommandTag	tag;
 
 	switch (nodeTag(parsetree))
 	{
@@ -2262,19 +2249,19 @@ CreateCommandTag(Node *parsetree)
 
 			/* raw plannable queries */
 		case T_InsertStmt:
-			tag = "INSERT";
+			tag = CMDTAG_INSERT;
 			break;
 
 		case T_DeleteStmt:
-			tag = "DELETE";
+			tag = CMDTAG_DELETE;
 			break;
 
 		case T_UpdateStmt:
-			tag = "UPDATE";
+			tag = CMDTAG_UPDATE;
 			break;
 
 		case T_SelectStmt:
-			tag = "SELECT";
+			tag = CMDTAG_SELECT;
 			break;
 
 			/* utility statements --- same whether raw or cooked */
@@ -2285,51 +2272,51 @@ CreateCommandTag(Node *parsetree)
 				switch (stmt->kind)
 				{
 					case TRANS_STMT_BEGIN:
-						tag = "BEGIN";
+						tag = CMDTAG_BEGIN;
 						break;
 
 					case TRANS_STMT_START:
-						tag = "START TRANSACTION";
+						tag = CMDTAG_START_TRANSACTION;
 						break;
 
 					case TRANS_STMT_COMMIT:
-						tag = "COMMIT";
+						tag = CMDTAG_COMMIT;
 						break;
 
 					case TRANS_STMT_ROLLBACK:
 					case TRANS_STMT_ROLLBACK_TO:
-						tag = "ROLLBACK";
+						tag = CMDTAG_ROLLBACK;
 						break;
 
 					case TRANS_STMT_SAVEPOINT:
-						tag = "SAVEPOINT";
+						tag = CMDTAG_SAVEPOINT;
 						break;
 
 					case TRANS_STMT_RELEASE:
-						tag = "RELEASE";
+						tag = CMDTAG_RELEASE;
 						break;
 
 					case TRANS_STMT_PREPARE:
-						tag = "PREPARE TRANSACTION";
+						tag = CMDTAG_PREPARE_TRANSACTION;
 						break;
 
 					case TRANS_STMT_COMMIT_PREPARED:
-						tag = "COMMIT PREPARED";
+						tag = CMDTAG_COMMIT_PREPARED;
 						break;
 
 					case TRANS_STMT_ROLLBACK_PREPARED:
-						tag = "ROLLBACK PREPARED";
+						tag = CMDTAG_ROLLBACK_PREPARED;
 						break;
 
 					default:
-						tag = "???";
+						tag = CMDTAG_UNKNOWN;
 						break;
 				}
 			}
 			break;
 
 		case T_DeclareCursorStmt:
-			tag = "DECLARE CURSOR";
+			tag = CMDTAG_DECLARE_CURSOR;
 			break;
 
 		case T_ClosePortalStmt:
@@ -2337,9 +2324,9 @@ CreateCommandTag(Node *parsetree)
 				ClosePortalStmt *stmt = (ClosePortalStmt *) parsetree;
 
 				if (stmt->portalname == NULL)
-					tag = "CLOSE CURSOR ALL";
+					tag = CMDTAG_CLOSE_CURSOR_ALL;
 				else
-					tag = "CLOSE CURSOR";
+					tag = CMDTAG_CLOSE_CURSOR;
 			}
 			break;
 
@@ -2347,209 +2334,209 @@ CreateCommandTag(Node *parsetree)
 			{
 				FetchStmt  *stmt = (FetchStmt *) parsetree;
 
-				tag = (stmt->ismove) ? "MOVE" : "FETCH";
+				tag = (stmt->ismove) ? CMDTAG_MOVE : CMDTAG_FETCH;
 			}
 			break;
 
 		case T_CreateDomainStmt:
-			tag = "CREATE DOMAIN";
+			tag = CMDTAG_CREATE_DOMAIN;
 			break;
 
 		case T_CreateSchemaStmt:
-			tag = "CREATE SCHEMA";
+			tag = CMDTAG_CREATE_SCHEMA;
 			break;
 
 		case T_CreateStmt:
-			tag = "CREATE TABLE";
+			tag = CMDTAG_CREATE_TABLE;
 			break;
 
 		case T_CreateTableSpaceStmt:
-			tag = "CREATE TABLESPACE";
+			tag = CMDTAG_CREATE_TABLESPACE;
 			break;
 
 		case T_DropTableSpaceStmt:
-			tag = "DROP TABLESPACE";
+			tag = CMDTAG_DROP_TABLESPACE;
 			break;
 
 		case T_AlterTableSpaceOptionsStmt:
-			tag = "ALTER TABLESPACE";
+			tag = CMDTAG_ALTER_TABLESPACE;
 			break;
 
 		case T_CreateExtensionStmt:
-			tag = "CREATE EXTENSION";
+			tag = CMDTAG_CREATE_EXTENSION;
 			break;
 
 		case T_AlterExtensionStmt:
-			tag = "ALTER EXTENSION";
+			tag = CMDTAG_ALTER_EXTENSION;
 			break;
 
 		case T_AlterExtensionContentsStmt:
-			tag = "ALTER EXTENSION";
+			tag = CMDTAG_ALTER_EXTENSION;
 			break;
 
 		case T_CreateFdwStmt:
-			tag = "CREATE FOREIGN DATA WRAPPER";
+			tag = CMDTAG_CREATE_FOREIGN_DATA_WRAPPER;
 			break;
 
 		case T_AlterFdwStmt:
-			tag = "ALTER FOREIGN DATA WRAPPER";
+			tag = CMDTAG_ALTER_FOREIGN_DATA_WRAPPER;
 			break;
 
 		case T_CreateForeignServerStmt:
-			tag = "CREATE SERVER";
+			tag = CMDTAG_CREATE_SERVER;
 			break;
 
 		case T_AlterForeignServerStmt:
-			tag = "ALTER SERVER";
+			tag = CMDTAG_ALTER_SERVER;
 			break;
 
 		case T_CreateUserMappingStmt:
-			tag = "CREATE USER MAPPING";
+			tag = CMDTAG_CREATE_USER_MAPPING;
 			break;
 
 		case T_AlterUserMappingStmt:
-			tag = "ALTER USER MAPPING";
+			tag = CMDTAG_ALTER_USER_MAPPING;
 			break;
 
 		case T_DropUserMappingStmt:
-			tag = "DROP USER MAPPING";
+			tag = CMDTAG_DROP_USER_MAPPING;
 			break;
 
 		case T_CreateForeignTableStmt:
-			tag = "CREATE FOREIGN TABLE";
+			tag = CMDTAG_CREATE_FOREIGN_TABLE;
 			break;
 
 		case T_ImportForeignSchemaStmt:
-			tag = "IMPORT FOREIGN SCHEMA";
+			tag = CMDTAG_IMPORT_FOREIGN_SCHEMA;
 			break;
 
 		case T_DropStmt:
 			switch (((DropStmt *) parsetree)->removeType)
 			{
 				case OBJECT_TABLE:
-					tag = "DROP TABLE";
+					tag = CMDTAG_DROP_TABLE;
 					break;
 				case OBJECT_SEQUENCE:
-					tag = "DROP SEQUENCE";
+					tag = CMDTAG_DROP_SEQUENCE;
 					break;
 				case OBJECT_VIEW:
-					tag = "DROP VIEW";
+					tag = CMDTAG_DROP_VIEW;
 					break;
 				case OBJECT_MATVIEW:
-					tag = "DROP MATERIALIZED VIEW";
+					tag = CMDTAG_DROP_MATERIALIZED_VIEW;
 					break;
 				case OBJECT_INDEX:
-					tag = "DROP INDEX";
+					tag = CMDTAG_DROP_INDEX;
 					break;
 				case OBJECT_TYPE:
-					tag = "DROP TYPE";
+					tag = CMDTAG_DROP_TYPE;
 					break;
 				case OBJECT_DOMAIN:
-					tag = "DROP DOMAIN";
+					tag = CMDTAG_DROP_DOMAIN;
 					break;
 				case OBJECT_COLLATION:
-					tag = "DROP COLLATION";
+					tag = CMDTAG_DROP_COLLATION;
 					break;
 				case OBJECT_CONVERSION:
-					tag = "DROP CONVERSION";
+					tag = CMDTAG_DROP_CONVERSION;
 					break;
 				case OBJECT_SCHEMA:
-					tag = "DROP SCHEMA";
+					tag = CMDTAG_DROP_SCHEMA;
 					break;
 				case OBJECT_TSPARSER:
-					tag = "DROP TEXT SEARCH PARSER";
+					tag = CMDTAG_DROP_TEXT_SEARCH_PARSER;
 					break;
 				case OBJECT_TSDICTIONARY:
-					tag = "DROP TEXT SEARCH DICTIONARY";
+					tag = CMDTAG_DROP_TEXT_SEARCH_DICTIONARY;
 					break;
 				case OBJECT_TSTEMPLATE:
-					tag = "DROP TEXT SEARCH TEMPLATE";
+					tag = CMDTAG_DROP_TEXT_SEARCH_TEMPLATE;
 					break;
 				case OBJECT_TSCONFIGURATION:
-					tag = "DROP TEXT SEARCH CONFIGURATION";
+					tag = CMDTAG_DROP_TEXT_SEARCH_CONFIGURATION;
 					break;
 				case OBJECT_FOREIGN_TABLE:
-					tag = "DROP FOREIGN TABLE";
+					tag = CMDTAG_DROP_FOREIGN_TABLE;
 					break;
 				case OBJECT_EXTENSION:
-					tag = "DROP EXTENSION";
+					tag = CMDTAG_DROP_EXTENSION;
 					break;
 				case OBJECT_FUNCTION:
-					tag = "DROP FUNCTION";
+					tag = CMDTAG_DROP_FUNCTION;
 					break;
 				case OBJECT_PROCEDURE:
-					tag = "DROP PROCEDURE";
+					tag = CMDTAG_DROP_PROCEDURE;
 					break;
 				case OBJECT_ROUTINE:
-					tag = "DROP ROUTINE";
+					tag = CMDTAG_DROP_ROUTINE;
 					break;
 				case OBJECT_AGGREGATE:
-					tag = "DROP AGGREGATE";
+					tag = CMDTAG_DROP_AGGREGATE;
 					break;
 				case OBJECT_OPERATOR:
-					tag = "DROP OPERATOR";
+					tag = CMDTAG_DROP_OPERATOR;
 					break;
 				case OBJECT_LANGUAGE:
-					tag = "DROP LANGUAGE";
+					tag = CMDTAG_DROP_LANGUAGE;
 					break;
 				case OBJECT_CAST:
-					tag = "DROP CAST";
+					tag = CMDTAG_DROP_CAST;
 					break;
 				case OBJECT_TRIGGER:
-					tag = "DROP TRIGGER";
+					tag = CMDTAG_DROP_TRIGGER;
 					break;
 				case OBJECT_EVENT_TRIGGER:
-					tag = "DROP EVENT TRIGGER";
+					tag = CMDTAG_DROP_EVENT_TRIGGER;
 					break;
 				case OBJECT_RULE:
-					tag = "DROP RULE";
+					tag = CMDTAG_DROP_RULE;
 					break;
 				case OBJECT_FDW:
-					tag = "DROP FOREIGN DATA WRAPPER";
+					tag = CMDTAG_DROP_FOREIGN_DATA_WRAPPER;
 					break;
 				case OBJECT_FOREIGN_SERVER:
-					tag = "DROP SERVER";
+					tag = CMDTAG_DROP_SERVER;
 					break;
 				case OBJECT_OPCLASS:
-					tag = "DROP OPERATOR CLASS";
+					tag = CMDTAG_DROP_OPERATOR_CLASS;
 					break;
 				case OBJECT_OPFAMILY:
-					tag = "DROP OPERATOR FAMILY";
+					tag = CMDTAG_DROP_OPERATOR_FAMILY;
 					break;
 				case OBJECT_POLICY:
-					tag = "DROP POLICY";
+					tag = CMDTAG_DROP_POLICY;
 					break;
 				case OBJECT_TRANSFORM:
-					tag = "DROP TRANSFORM";
+					tag = CMDTAG_DROP_TRANSFORM;
 					break;
 				case OBJECT_ACCESS_METHOD:
-					tag = "DROP ACCESS METHOD";
+					tag = CMDTAG_DROP_ACCESS_METHOD;
 					break;
 				case OBJECT_PUBLICATION:
-					tag = "DROP PUBLICATION";
+					tag = CMDTAG_DROP_PUBLICATION;
 					break;
 				case OBJECT_STATISTIC_EXT:
-					tag = "DROP STATISTICS";
+					tag = CMDTAG_DROP_STATISTICS;
 					break;
 				default:
-					tag = "???";
+					tag = CMDTAG_UNKNOWN;
 			}
 			break;
 
 		case T_TruncateStmt:
-			tag = "TRUNCATE TABLE";
+			tag = CMDTAG_TRUNCATE_TABLE;
 			break;
 
 		case T_CommentStmt:
-			tag = "COMMENT";
+			tag = CMDTAG_COMMENT;
 			break;
 
 		case T_SecLabelStmt:
-			tag = "SECURITY LABEL";
+			tag = CMDTAG_SECURITY_LABEL;
 			break;
 
 		case T_CopyStmt:
-			tag = "COPY";
+			tag = CMDTAG_COPY;
 			break;
 
 		case T_RenameStmt:
@@ -2584,23 +2571,23 @@ CreateCommandTag(Node *parsetree)
 			break;
 
 		case T_AlterDomainStmt:
-			tag = "ALTER DOMAIN";
+			tag = CMDTAG_ALTER_DOMAIN;
 			break;
 
 		case T_AlterFunctionStmt:
 			switch (((AlterFunctionStmt *) parsetree)->objtype)
 			{
 				case OBJECT_FUNCTION:
-					tag = "ALTER FUNCTION";
+					tag = CMDTAG_ALTER_FUNCTION;
 					break;
 				case OBJECT_PROCEDURE:
-					tag = "ALTER PROCEDURE";
+					tag = CMDTAG_ALTER_PROCEDURE;
 					break;
 				case OBJECT_ROUTINE:
-					tag = "ALTER ROUTINE";
+					tag = CMDTAG_ALTER_ROUTINE;
 					break;
 				default:
-					tag = "???";
+					tag = CMDTAG_UNKNOWN;
 			}
 			break;
 
@@ -2608,7 +2595,7 @@ CreateCommandTag(Node *parsetree)
 			{
 				GrantStmt  *stmt = (GrantStmt *) parsetree;
 
-				tag = (stmt->is_grant) ? "GRANT" : "REVOKE";
+				tag = (stmt->is_grant) ? CMDTAG_GRANT : CMDTAG_REVOKE;
 			}
 			break;
 
@@ -2616,145 +2603,145 @@ CreateCommandTag(Node *parsetree)
 			{
 				GrantRoleStmt *stmt = (GrantRoleStmt *) parsetree;
 
-				tag = (stmt->is_grant) ? "GRANT ROLE" : "REVOKE ROLE";
+				tag = (stmt->is_grant) ? CMDTAG_GRANT_ROLE : CMDTAG_REVOKE_ROLE;
 			}
 			break;
 
 		case T_AlterDefaultPrivilegesStmt:
-			tag = "ALTER DEFAULT PRIVILEGES";
+			tag = CMDTAG_ALTER_DEFAULT_PRIVILEGES;
 			break;
 
 		case T_DefineStmt:
 			switch (((DefineStmt *) parsetree)->kind)
 			{
 				case OBJECT_AGGREGATE:
-					tag = "CREATE AGGREGATE";
+					tag = CMDTAG_CREATE_AGGREGATE;
 					break;
 				case OBJECT_OPERATOR:
-					tag = "CREATE OPERATOR";
+					tag = CMDTAG_CREATE_OPERATOR;
 					break;
 				case OBJECT_TYPE:
-					tag = "CREATE TYPE";
+					tag = CMDTAG_CREATE_TYPE;
 					break;
 				case OBJECT_TSPARSER:
-					tag = "CREATE TEXT SEARCH PARSER";
+					tag = CMDTAG_CREATE_TEXT_SEARCH_PARSER;
 					break;
 				case OBJECT_TSDICTIONARY:
-					tag = "CREATE TEXT SEARCH DICTIONARY";
+					tag = CMDTAG_CREATE_TEXT_SEARCH_DICTIONARY;
 					break;
 				case OBJECT_TSTEMPLATE:
-					tag = "CREATE TEXT SEARCH TEMPLATE";
+					tag = CMDTAG_CREATE_TEXT_SEARCH_TEMPLATE;
 					break;
 				case OBJECT_TSCONFIGURATION:
-					tag = "CREATE TEXT SEARCH CONFIGURATION";
+					tag = CMDTAG_CREATE_TEXT_SEARCH_CONFIGURATION;
 					break;
 				case OBJECT_COLLATION:
-					tag = "CREATE COLLATION";
+					tag = CMDTAG_CREATE_COLLATION;
 					break;
 				case OBJECT_ACCESS_METHOD:
-					tag = "CREATE ACCESS METHOD";
+					tag = CMDTAG_CREATE_ACCESS_METHOD;
 					break;
 				default:
-					tag = "???";
+					tag = CMDTAG_UNKNOWN;
 			}
 			break;
 
 		case T_CompositeTypeStmt:
-			tag = "CREATE TYPE";
+			tag = CMDTAG_CREATE_TYPE;
 			break;
 
 		case T_CreateEnumStmt:
-			tag = "CREATE TYPE";
+			tag = CMDTAG_CREATE_TYPE;
 			break;
 
 		case T_CreateRangeStmt:
-			tag = "CREATE TYPE";
+			tag = CMDTAG_CREATE_TYPE;
 			break;
 
 		case T_AlterEnumStmt:
-			tag = "ALTER TYPE";
+			tag = CMDTAG_ALTER_TYPE;
 			break;
 
 		case T_ViewStmt:
-			tag = "CREATE VIEW";
+			tag = CMDTAG_CREATE_VIEW;
 			break;
 
 		case T_CreateFunctionStmt:
 			if (((CreateFunctionStmt *) parsetree)->is_procedure)
-				tag = "CREATE PROCEDURE";
+				tag = CMDTAG_CREATE_PROCEDURE;
 			else
-				tag = "CREATE FUNCTION";
+				tag = CMDTAG_CREATE_FUNCTION;
 			break;
 
 		case T_IndexStmt:
-			tag = "CREATE INDEX";
+			tag = CMDTAG_CREATE_INDEX;
 			break;
 
 		case T_RuleStmt:
-			tag = "CREATE RULE";
+			tag = CMDTAG_CREATE_RULE;
 			break;
 
 		case T_CreateSeqStmt:
-			tag = "CREATE SEQUENCE";
+			tag = CMDTAG_CREATE_SEQUENCE;
 			break;
 
 		case T_AlterSeqStmt:
-			tag = "ALTER SEQUENCE";
+			tag = CMDTAG_ALTER_SEQUENCE;
 			break;
 
 		case T_DoStmt:
-			tag = "DO";
+			tag = CMDTAG_DO;
 			break;
 
 		case T_CreatedbStmt:
-			tag = "CREATE DATABASE";
+			tag = CMDTAG_CREATE_DATABASE;
 			break;
 
 		case T_AlterDatabaseStmt:
-			tag = "ALTER DATABASE";
+			tag = CMDTAG_ALTER_DATABASE;
 			break;
 
 		case T_AlterDatabaseSetStmt:
-			tag = "ALTER DATABASE";
+			tag = CMDTAG_ALTER_DATABASE;
 			break;
 
 		case T_DropdbStmt:
-			tag = "DROP DATABASE";
+			tag = CMDTAG_DROP_DATABASE;
 			break;
 
 		case T_NotifyStmt:
-			tag = "NOTIFY";
+			tag = CMDTAG_NOTIFY;
 			break;
 
 		case T_ListenStmt:
-			tag = "LISTEN";
+			tag = CMDTAG_LISTEN;
 			break;
 
 		case T_UnlistenStmt:
-			tag = "UNLISTEN";
+			tag = CMDTAG_UNLISTEN;
 			break;
 
 		case T_LoadStmt:
-			tag = "LOAD";
+			tag = CMDTAG_LOAD;
 			break;
 
 		case T_CallStmt:
-			tag = "CALL";
+			tag = CMDTAG_CALL;
 			break;
 
 		case T_ClusterStmt:
-			tag = "CLUSTER";
+			tag = CMDTAG_CLUSTER;
 			break;
 
 		case T_VacuumStmt:
 			if (((VacuumStmt *) parsetree)->is_vacuumcmd)
-				tag = "VACUUM";
+				tag = CMDTAG_VACUUM;
 			else
-				tag = "ANALYZE";
+				tag = CMDTAG_ANALYZE;
 			break;
 
 		case T_ExplainStmt:
-			tag = "EXPLAIN";
+			tag = CMDTAG_EXPLAIN;
 			break;
 
 		case T_CreateTableAsStmt:
@@ -2762,24 +2749,24 @@ CreateCommandTag(Node *parsetree)
 			{
 				case OBJECT_TABLE:
 					if (((CreateTableAsStmt *) parsetree)->is_select_into)
-						tag = "SELECT INTO";
+						tag = CMDTAG_SELECT_INTO;
 					else
-						tag = "CREATE TABLE AS";
+						tag = CMDTAG_CREATE_TABLE_AS;
 					break;
 				case OBJECT_MATVIEW:
-					tag = "CREATE MATERIALIZED VIEW";
+					tag = CMDTAG_CREATE_MATERIALIZED_VIEW;
 					break;
 				default:
-					tag = "???";
+					tag = CMDTAG_UNKNOWN;
 			}
 			break;
 
 		case T_RefreshMatViewStmt:
-			tag = "REFRESH MATERIALIZED VIEW";
+			tag = CMDTAG_REFRESH_MATERIALIZED_VIEW;
 			break;
 
 		case T_AlterSystemStmt:
-			tag = "ALTER SYSTEM";
+			tag = CMDTAG_ALTER_SYSTEM;
 			break;
 
 		case T_VariableSetStmt:
@@ -2789,183 +2776,183 @@ CreateCommandTag(Node *parsetree)
 				case VAR_SET_CURRENT:
 				case VAR_SET_DEFAULT:
 				case VAR_SET_MULTI:
-					tag = "SET";
+					tag = CMDTAG_SET;
 					break;
 				case VAR_RESET:
 				case VAR_RESET_ALL:
-					tag = "RESET";
+					tag = CMDTAG_RESET;
 					break;
 				default:
-					tag = "???";
+					tag = CMDTAG_UNKNOWN;
 			}
 			break;
 
 		case T_VariableShowStmt:
-			tag = "SHOW";
+			tag = CMDTAG_SHOW;
 			break;
 
 		case T_DiscardStmt:
 			switch (((DiscardStmt *) parsetree)->target)
 			{
 				case DISCARD_ALL:
-					tag = "DISCARD ALL";
+					tag = CMDTAG_DISCARD_ALL;
 					break;
 				case DISCARD_PLANS:
-					tag = "DISCARD PLANS";
+					tag = CMDTAG_DISCARD_PLANS;
 					break;
 				case DISCARD_TEMP:
-					tag = "DISCARD TEMP";
+					tag = CMDTAG_DISCARD_TEMP;
 					break;
 				case DISCARD_SEQUENCES:
-					tag = "DISCARD SEQUENCES";
+					tag = CMDTAG_DISCARD_SEQUENCES;
 					break;
 				default:
-					tag = "???";
+					tag = CMDTAG_UNKNOWN;
 			}
 			break;
 
 		case T_CreateTransformStmt:
-			tag = "CREATE TRANSFORM";
+			tag = CMDTAG_CREATE_TRANSFORM;
 			break;
 
 		case T_CreateTrigStmt:
-			tag = "CREATE TRIGGER";
+			tag = CMDTAG_CREATE_TRIGGER;
 			break;
 
 		case T_CreateEventTrigStmt:
-			tag = "CREATE EVENT TRIGGER";
+			tag = CMDTAG_CREATE_EVENT_TRIGGER;
 			break;
 
 		case T_AlterEventTrigStmt:
-			tag = "ALTER EVENT TRIGGER";
+			tag = CMDTAG_ALTER_EVENT_TRIGGER;
 			break;
 
 		case T_CreatePLangStmt:
-			tag = "CREATE LANGUAGE";
+			tag = CMDTAG_CREATE_LANGUAGE;
 			break;
 
 		case T_CreateRoleStmt:
-			tag = "CREATE ROLE";
+			tag = CMDTAG_CREATE_ROLE;
 			break;
 
 		case T_AlterRoleStmt:
-			tag = "ALTER ROLE";
+			tag = CMDTAG_ALTER_ROLE;
 			break;
 
 		case T_AlterRoleSetStmt:
-			tag = "ALTER ROLE";
+			tag = CMDTAG_ALTER_ROLE;
 			break;
 
 		case T_DropRoleStmt:
-			tag = "DROP ROLE";
+			tag = CMDTAG_DROP_ROLE;
 			break;
 
 		case T_DropOwnedStmt:
-			tag = "DROP OWNED";
+			tag = CMDTAG_DROP_OWNED;
 			break;
 
 		case T_ReassignOwnedStmt:
-			tag = "REASSIGN OWNED";
+			tag = CMDTAG_REASSIGN_OWNED;
 			break;
 
 		case T_LockStmt:
-			tag = "LOCK TABLE";
+			tag = CMDTAG_LOCK_TABLE;
 			break;
 
 		case T_ConstraintsSetStmt:
-			tag = "SET CONSTRAINTS";
+			tag = CMDTAG_SET_CONSTRAINTS;
 			break;
 
 		case T_CheckPointStmt:
-			tag = "CHECKPOINT";
+			tag = CMDTAG_CHECKPOINT;
 			break;
 
 		case T_ReindexStmt:
-			tag = "REINDEX";
+			tag = CMDTAG_REINDEX;
 			break;
 
 		case T_CreateConversionStmt:
-			tag = "CREATE CONVERSION";
+			tag = CMDTAG_CREATE_CONVERSION;
 			break;
 
 		case T_CreateCastStmt:
-			tag = "CREATE CAST";
+			tag = CMDTAG_CREATE_CAST;
 			break;
 
 		case T_CreateOpClassStmt:
-			tag = "CREATE OPERATOR CLASS";
+			tag = CMDTAG_CREATE_OPERATOR_CLASS;
 			break;
 
 		case T_CreateOpFamilyStmt:
-			tag = "CREATE OPERATOR FAMILY";
+			tag = CMDTAG_CREATE_OPERATOR_FAMILY;
 			break;
 
 		case T_AlterOpFamilyStmt:
-			tag = "ALTER OPERATOR FAMILY";
+			tag = CMDTAG_ALTER_OPERATOR_FAMILY;
 			break;
 
 		case T_AlterOperatorStmt:
-			tag = "ALTER OPERATOR";
+			tag = CMDTAG_ALTER_OPERATOR;
 			break;
 
 		case T_AlterTSDictionaryStmt:
-			tag = "ALTER TEXT SEARCH DICTIONARY";
+			tag = CMDTAG_ALTER_TEXT_SEARCH_DICTIONARY;
 			break;
 
 		case T_AlterTSConfigurationStmt:
-			tag = "ALTER TEXT SEARCH CONFIGURATION";
+			tag = CMDTAG_ALTER_TEXT_SEARCH_CONFIGURATION;
 			break;
 
 		case T_CreatePolicyStmt:
-			tag = "CREATE POLICY";
+			tag = CMDTAG_CREATE_POLICY;
 			break;
 
 		case T_AlterPolicyStmt:
-			tag = "ALTER POLICY";
+			tag = CMDTAG_ALTER_POLICY;
 			break;
 
 		case T_CreateAmStmt:
-			tag = "CREATE ACCESS METHOD";
+			tag = CMDTAG_CREATE_ACCESS_METHOD;
 			break;
 
 		case T_CreatePublicationStmt:
-			tag = "CREATE PUBLICATION";
+			tag = CMDTAG_CREATE_PUBLICATION;
 			break;
 
 		case T_AlterPublicationStmt:
-			tag = "ALTER PUBLICATION";
+			tag = CMDTAG_ALTER_PUBLICATION;
 			break;
 
 		case T_CreateSubscriptionStmt:
-			tag = "CREATE SUBSCRIPTION";
+			tag = CMDTAG_CREATE_SUBSCRIPTION;
 			break;
 
 		case T_AlterSubscriptionStmt:
-			tag = "ALTER SUBSCRIPTION";
+			tag = CMDTAG_ALTER_SUBSCRIPTION;
 			break;
 
 		case T_DropSubscriptionStmt:
-			tag = "DROP SUBSCRIPTION";
+			tag = CMDTAG_DROP_SUBSCRIPTION;
 			break;
 
 		case T_AlterCollationStmt:
-			tag = "ALTER COLLATION";
+			tag = CMDTAG_ALTER_COLLATION;
 			break;
 
 		case T_PrepareStmt:
-			tag = "PREPARE";
+			tag = CMDTAG_PREPARE;
 			break;
 
 		case T_ExecuteStmt:
-			tag = "EXECUTE";
+			tag = CMDTAG_EXECUTE;
 			break;
 
 		case T_CreateStatsStmt:
-			tag = "CREATE STATISTICS";
+			tag = CMDTAG_CREATE_STATISTICS;
 			break;
 
 		case T_AlterStatsStmt:
-			tag = "ALTER STATISTICS";
+			tag = CMDTAG_ALTER_STATISTICS;
 			break;
 
 		case T_DeallocateStmt:
@@ -2973,9 +2960,9 @@ CreateCommandTag(Node *parsetree)
 				DeallocateStmt *stmt = (DeallocateStmt *) parsetree;
 
 				if (stmt->name == NULL)
-					tag = "DEALLOCATE ALL";
+					tag = CMDTAG_DEALLOCATE_ALL;
 				else
-					tag = "DEALLOCATE";
+					tag = CMDTAG_DEALLOCATE;
 			}
 			break;
 
@@ -2999,33 +2986,33 @@ CreateCommandTag(Node *parsetree)
 							switch (((PlanRowMark *) linitial(stmt->rowMarks))->strength)
 							{
 								case LCS_FORKEYSHARE:
-									tag = "SELECT FOR KEY SHARE";
+									tag = CMDTAG_SELECT_FOR_KEY_SHARE;
 									break;
 								case LCS_FORSHARE:
-									tag = "SELECT FOR SHARE";
+									tag = CMDTAG_SELECT_FOR_SHARE;
 									break;
 								case LCS_FORNOKEYUPDATE:
-									tag = "SELECT FOR NO KEY UPDATE";
+									tag = CMDTAG_SELECT_FOR_NO_KEY_UPDATE;
 									break;
 								case LCS_FORUPDATE:
-									tag = "SELECT FOR UPDATE";
+									tag = CMDTAG_SELECT_FOR_UPDATE;
 									break;
 								default:
-									tag = "SELECT";
+									tag = CMDTAG_SELECT;
 									break;
 							}
 						}
 						else
-							tag = "SELECT";
+							tag = CMDTAG_SELECT;
 						break;
 					case CMD_UPDATE:
-						tag = "UPDATE";
+						tag = CMDTAG_UPDATE;
 						break;
 					case CMD_INSERT:
-						tag = "INSERT";
+						tag = CMDTAG_INSERT;
 						break;
 					case CMD_DELETE:
-						tag = "DELETE";
+						tag = CMDTAG_DELETE;
 						break;
 					case CMD_UTILITY:
 						tag = CreateCommandTag(stmt->utilityStmt);
@@ -3033,7 +3020,7 @@ CreateCommandTag(Node *parsetree)
 					default:
 						elog(WARNING, "unrecognized commandType: %d",
 							 (int) stmt->commandType);
-						tag = "???";
+						tag = CMDTAG_UNKNOWN;
 						break;
 				}
 			}
@@ -3059,33 +3046,33 @@ CreateCommandTag(Node *parsetree)
 							switch (((RowMarkClause *) linitial(stmt->rowMarks))->strength)
 							{
 								case LCS_FORKEYSHARE:
-									tag = "SELECT FOR KEY SHARE";
+									tag = CMDTAG_SELECT_FOR_KEY_SHARE;
 									break;
 								case LCS_FORSHARE:
-									tag = "SELECT FOR SHARE";
+									tag = CMDTAG_SELECT_FOR_SHARE;
 									break;
 								case LCS_FORNOKEYUPDATE:
-									tag = "SELECT FOR NO KEY UPDATE";
+									tag = CMDTAG_SELECT_FOR_NO_KEY_UPDATE;
 									break;
 								case LCS_FORUPDATE:
-									tag = "SELECT FOR UPDATE";
+									tag = CMDTAG_SELECT_FOR_UPDATE;
 									break;
 								default:
-									tag = "???";
+									tag = CMDTAG_UNKNOWN;
 									break;
 							}
 						}
 						else
-							tag = "SELECT";
+							tag = CMDTAG_SELECT;
 						break;
 					case CMD_UPDATE:
-						tag = "UPDATE";
+						tag = CMDTAG_UPDATE;
 						break;
 					case CMD_INSERT:
-						tag = "INSERT";
+						tag = CMDTAG_INSERT;
 						break;
 					case CMD_DELETE:
-						tag = "DELETE";
+						tag = CMDTAG_DELETE;
 						break;
 					case CMD_UTILITY:
 						tag = CreateCommandTag(stmt->utilityStmt);
@@ -3093,7 +3080,7 @@ CreateCommandTag(Node *parsetree)
 					default:
 						elog(WARNING, "unrecognized commandType: %d",
 							 (int) stmt->commandType);
-						tag = "???";
+						tag = CMDTAG_UNKNOWN;
 						break;
 				}
 			}
@@ -3102,7 +3089,7 @@ CreateCommandTag(Node *parsetree)
 		default:
 			elog(WARNING, "unrecognized node type: %d",
 				 (int) nodeTag(parsetree));
-			tag = "???";
+			tag = CMDTAG_UNKNOWN;
 			break;
 	}