Add a relkind field to RangeTblEntry to avoid some syscache lookups.

The recent additions for FDW support required checking foreign-table-ness
in several places in the parse/plan chain.  While it's not clear whether
that would really result in a noticeable slowdown, it seems best to avoid
any performance risk by keeping a copy of the relation's relkind in
RangeTblEntry.  That might have some other uses later, anyway.
Per discussion.

3 files changed, 9 insertions, 18 deletions

diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index c7a7a230767..7f28d9df4f5 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -40,7 +40,6 @@
 #include "parser/parse_target.h"
 #include "parser/parsetree.h"
 #include "rewrite/rewriteManip.h"
-#include "utils/lsyscache.h"
 #include "utils/rel.h"
 
 
@@ -2178,13 +2177,11 @@ transformLockingClause(ParseState *pstate, Query *qry, LockingClause *lc,
 			{
 				case RTE_RELATION:
 					/* ignore foreign tables */
-					if (get_rel_relkind(rte->relid) != RELKIND_FOREIGN_TABLE)
-					{
-						applyLockingClause(qry, i,
-										   lc->forUpdate, lc->noWait,
-										   pushedDown);
-						rte->requiredPerms |= ACL_SELECT_FOR_UPDATE;
-					}
+					if (rte->relkind == RELKIND_FOREIGN_TABLE)
+						break;
+					applyLockingClause(qry, i,
+									   lc->forUpdate, lc->noWait, pushedDown);
+					rte->requiredPerms |= ACL_SELECT_FOR_UPDATE;
 					break;
 				case RTE_SUBQUERY:
 					applyLockingClause(qry, i,
@@ -2231,11 +2228,11 @@ transformLockingClause(ParseState *pstate, Query *qry, LockingClause *lc,
 					switch (rte->rtekind)
 					{
 						case RTE_RELATION:
-							if (get_rel_relkind(rte->relid) == RELKIND_FOREIGN_TABLE)
+							if (rte->relkind == RELKIND_FOREIGN_TABLE)
 								ereport(ERROR,
 										(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 										 errmsg("SELECT FOR UPDATE/SHARE cannot be used with foreign table \"%s\"",
-												get_rel_name(rte->relid)),
+												rte->eref->aliasname),
 										 parser_errposition(pstate, thisrel->location)));
 							applyLockingClause(qry, i,
 											   lc->forUpdate, lc->noWait,
@@ -2256,12 +2253,6 @@ transformLockingClause(ParseState *pstate, Query *qry, LockingClause *lc,
 									 errmsg("SELECT FOR UPDATE/SHARE cannot be applied to a join"),
 							 parser_errposition(pstate, thisrel->location)));
 							break;
-						case RTE_SPECIAL:
-							ereport(ERROR,
-									(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-									 errmsg("SELECT FOR UPDATE/SHARE cannot be applied to NEW or OLD"),
-							 parser_errposition(pstate, thisrel->location)));
-							break;
 						case RTE_FUNCTION:
 							ereport(ERROR,
 									(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
diff --git a/src/backend/parser/parse_relation.c b/src/backend/parser/parse_relation.c
index 497c726f314..033ed411fde 100644
--- a/src/backend/parser/parse_relation.c
+++ b/src/backend/parser/parse_relation.c
@@ -894,6 +894,7 @@ addRangeTableEntry(ParseState *pstate,
 	lockmode = isLockedRefname(pstate, refname) ? RowShareLock : AccessShareLock;
 	rel = parserOpenTable(pstate, relation, lockmode);
 	rte->relid = RelationGetRelid(rel);
+	rte->relkind = rel->rd_rel->relkind;
 
 	/*
 	 * Build the list of effective column names using user-supplied aliases
@@ -956,6 +957,7 @@ addRangeTableEntryForRelation(ParseState *pstate,
 	rte->rtekind = RTE_RELATION;
 	rte->alias = alias;
 	rte->relid = RelationGetRelid(rel);
+	rte->relkind = rel->rd_rel->relkind;
 
 	/*
 	 * Build the list of effective column names using user-supplied aliases
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index a0761da875b..e9ace37e2d8 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -305,7 +305,6 @@ markTargetListOrigin(ParseState *pstate, TargetEntry *tle,
 				markTargetListOrigin(pstate, tle, aliasvar, netlevelsup);
 			}
 			break;
-		case RTE_SPECIAL:
 		case RTE_FUNCTION:
 		case RTE_VALUES:
 			/* not a simple relation, leave it unmarked */
@@ -1357,7 +1356,6 @@ expandRecordVariable(ParseState *pstate, Var *var, int levelsup)
 	switch (rte->rtekind)
 	{
 		case RTE_RELATION:
-		case RTE_SPECIAL:
 		case RTE_VALUES:
 
 			/*