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.

diff --git a/src/backend/catalog/dependency.c b/src/backend/catalog/dependency.c
index 1679776f019faf1a4ced3f9d809f5373c79481cb..bce0e076837f57857c8c19d82b08f5cb51b1f766 100644 (file)
--- a/src/backend/catalog/dependency.c
+++ b/src/backend/catalog/dependency.c
@@ -1284,6 +1284,7 @@ recordDependencyOnSingleRelExpr(const ObjectAddress *depender,
    rte.type = T_RangeTblEntry;
    rte.rtekind = RTE_RELATION;
    rte.relid = relId;
+   rte.relkind = RELKIND_RELATION;     /* no need for exactness here */
 
    context.rtables = list_make1(list_make1(&rte));
 

diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c
index 44f568f396414f69485ab0538b0086741e5068c9..3c504e96be2d3f426269bdbd61ef4632c6ceb75f 100644 (file)
--- a/src/backend/commands/copy.c
+++ b/src/backend/commands/copy.c
@@ -763,6 +763,7 @@ DoCopy(const CopyStmt *stmt, const char *queryString)
        rte = makeNode(RangeTblEntry);
        rte->rtekind = RTE_RELATION;
        rte->relid = RelationGetRelid(rel);
+       rte->relkind = rel->rd_rel->relkind;
        rte->requiredPerms = required_access;
 
        tupDesc = RelationGetDescr(rel);

diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index 1ba746bb4d893c0145e8376553c468d5b086fe1c..04763d44ebb6e38342d2c4d483e780e6b3360a4f 100644 (file)
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -1927,6 +1927,7 @@ _copyRangeTblEntry(RangeTblEntry *from)
 
    COPY_SCALAR_FIELD(rtekind);
    COPY_SCALAR_FIELD(relid);
+   COPY_SCALAR_FIELD(relkind);
    COPY_NODE_FIELD(subquery);
    COPY_SCALAR_FIELD(jointype);
    COPY_NODE_FIELD(joinaliasvars);

diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index dd332f19f00d91baec544229a6b98772028a9f5b..c896f49ff6f3a7d809063f13a2defc63f5c90e79 100644 (file)
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -2286,6 +2286,7 @@ _equalRangeTblEntry(RangeTblEntry *a, RangeTblEntry *b)
 {
    COMPARE_SCALAR_FIELD(rtekind);
    COMPARE_SCALAR_FIELD(relid);
+   COMPARE_SCALAR_FIELD(relkind);
    COMPARE_NODE_FIELD(subquery);
    COMPARE_SCALAR_FIELD(jointype);
    COMPARE_NODE_FIELD(joinaliasvars);

diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index 8a23047d382e9474aa3eea0bffa89ac2259a3a81..d4b9242917197263578fd949c6c29b06a1b99a03 100644 (file)
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -1671,7 +1671,6 @@ range_table_walker(List *rtable,
        switch (rte->rtekind)
        {
            case RTE_RELATION:
-           case RTE_SPECIAL:
            case RTE_CTE:
                /* nothing to do */
                break;
@@ -2374,7 +2373,6 @@ range_table_mutator(List *rtable,
        switch (rte->rtekind)
        {
            case RTE_RELATION:
-           case RTE_SPECIAL:
            case RTE_CTE:
                /* we don't bother to copy eref, aliases, etc; OK? */
                break;

diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index 10f630e27f5b14f695540984feee31c096655ce2..706b2425cf2b1516b47128824083af1e0b127dad 100644 (file)
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -2275,8 +2275,8 @@ _outRangeTblEntry(StringInfo str, RangeTblEntry *node)
    switch (node->rtekind)
    {
        case RTE_RELATION:
-       case RTE_SPECIAL:
            WRITE_OID_FIELD(relid);
+           WRITE_CHAR_FIELD(relkind);
            break;
        case RTE_SUBQUERY:
            WRITE_NODE_FIELD(subquery);

diff --git a/src/backend/nodes/print.c b/src/backend/nodes/print.c
index 14487f25a1044cfa240f3cdc1ad4bfb0d41551f1..cd119dbabb8c78a72af30a0902397680328c26db 100644 (file)
--- a/src/backend/nodes/print.c
+++ b/src/backend/nodes/print.c
@@ -265,8 +265,8 @@ print_rt(List *rtable)
        switch (rte->rtekind)
        {
            case RTE_RELATION:
-               printf("%d\t%s\t%u",
-                      i, rte->eref->aliasname, rte->relid);
+               printf("%d\t%s\t%u\t%c",
+                      i, rte->eref->aliasname, rte->relid, rte->relkind);
                break;
            case RTE_SUBQUERY:
                printf("%d\t%s\t[subquery]",
@@ -276,10 +276,6 @@ print_rt(List *rtable)
                printf("%d\t%s\t[join]",
                       i, rte->eref->aliasname);
                break;
-           case RTE_SPECIAL:
-               printf("%d\t%s\t[special]",
-                      i, rte->eref->aliasname);
-               break;
            case RTE_FUNCTION:
                printf("%d\t%s\t[rangefunction]",
                       i, rte->eref->aliasname);

diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c
index b007caeee3e1ecb4238632e53c7de6c2b3328c8e..c76884e991f4b2eeca8a38b4ef32ae24017b86f8 100644 (file)
--- a/src/backend/nodes/readfuncs.c
+++ b/src/backend/nodes/readfuncs.c
@@ -1171,8 +1171,8 @@ _readRangeTblEntry(void)
    switch (local_node->rtekind)
    {
        case RTE_RELATION:
-       case RTE_SPECIAL:
            READ_OID_FIELD(relid);
+           READ_CHAR_FIELD(relkind);
            break;
        case RTE_SUBQUERY:
            READ_NODE_FIELD(subquery);

diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c
index c835a954ed97b29e87adb933af5078f27fc9971b..dc2a23bb2737313b43e1e6d7b272119863693cbc 100644 (file)
--- a/src/backend/optimizer/path/allpaths.c
+++ b/src/backend/optimizer/path/allpaths.c
@@ -176,41 +176,44 @@ set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
        /* It's an "append relation", process accordingly */
        set_append_rel_pathlist(root, rel, rti, rte);
    }
-   else if (rel->rtekind == RTE_SUBQUERY)
-   {
-       /* Subquery --- generate a separate plan for it */
-       set_subquery_pathlist(root, rel, rti, rte);
-   }
-   else if (rel->rtekind == RTE_FUNCTION)
-   {
-       /* RangeFunction --- generate a suitable path for it */
-       set_function_pathlist(root, rel, rte);
-   }
-   else if (rel->rtekind == RTE_VALUES)
-   {
-       /* Values list --- generate a suitable path for it */
-       set_values_pathlist(root, rel, rte);
-   }
-   else if (rel->rtekind == RTE_CTE)
-   {
-       /* CTE reference --- generate a suitable path for it */
-       if (rte->self_reference)
-           set_worktable_pathlist(root, rel, rte);
-       else
-           set_cte_pathlist(root, rel, rte);
-   }
    else
    {
-       Assert(rel->rtekind == RTE_RELATION);
-       if (get_rel_relkind(rte->relid) == RELKIND_FOREIGN_TABLE)
-       {
-           /* Foreign table */
-           set_foreign_pathlist(root, rel, rte);
-       }
-       else
+       switch (rel->rtekind)
        {
-           /* Plain relation */
-           set_plain_rel_pathlist(root, rel, rte);
+           case RTE_RELATION:
+               if (rte->relkind == RELKIND_FOREIGN_TABLE)
+               {
+                   /* Foreign table */
+                   set_foreign_pathlist(root, rel, rte);
+               }
+               else
+               {
+                   /* Plain relation */
+                   set_plain_rel_pathlist(root, rel, rte);
+               }
+               break;
+           case RTE_SUBQUERY:
+               /* Subquery --- generate a separate plan for it */
+               set_subquery_pathlist(root, rel, rti, rte);
+               break;
+           case RTE_FUNCTION:
+               /* RangeFunction --- generate a suitable path for it */
+               set_function_pathlist(root, rel, rte);
+               break;
+           case RTE_VALUES:
+               /* Values list --- generate a suitable path for it */
+               set_values_pathlist(root, rel, rte);
+               break;
+           case RTE_CTE:
+               /* CTE reference --- generate a suitable path for it */
+               if (rte->self_reference)
+                   set_worktable_pathlist(root, rel, rte);
+               else
+                   set_cte_pathlist(root, rel, rte);
+               break;
+           default:
+               elog(ERROR, "unexpected rtekind: %d", (int) rel->rtekind);
+               break;
        }
    }
 

diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index b73b872b3128f40b9a4bcfff01fd2e1aac20f62c..ee09673051ff0e03f61622d5fee7c8d151886b87 100644 (file)
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -1915,7 +1915,7 @@ preprocess_rowmarks(PlannerInfo *root)
        newrc->rowmarkId = ++(root->glob->lastRowMarkId);
        /* real tables support REFERENCE, anything else needs COPY */
        if (rte->rtekind == RTE_RELATION &&
-           get_rel_relkind(rte->relid) != RELKIND_FOREIGN_TABLE)
+           rte->relkind != RELKIND_FOREIGN_TABLE)
            newrc->markType = ROW_MARK_REFERENCE;
        else
            newrc->markType = ROW_MARK_COPY;
@@ -3078,6 +3078,7 @@ plan_cluster_use_sort(Oid tableOid, Oid indexOid)
    rte = makeNode(RangeTblEntry);
    rte->rtekind = RTE_RELATION;
    rte->relid = tableOid;
+   rte->relkind = RELKIND_RELATION;
    rte->inh = false;
    rte->inFromCl = true;
    query->rtable = list_make1(rte);

diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index c7a7a230767889d332c037d866d42160e8e8f7f9..7f28d9df4f5ea701d21162a00da96e1bf3c5af1c 100644 (file)
--- 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 497c726f31455fc6f24a0533bc3c411ce545e87b..033ed411fde92d7bd60c9889d6e0872be73e9a7f 100644 (file)
--- 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 a0761da875be78c7387bc0053e6b68f2852eab9b..e9ace37e2d803fd47b132ca228f16465dce5851f 100644 (file)
--- 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:
 
            /*

diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c
index 3a50642fce8008d6b99b816515022cd10773d232..c0d25b15c60c3e20e887fa976cb3641b7352c6fd 100644 (file)
--- a/src/backend/rewrite/rewriteHandler.c
+++ b/src/backend/rewrite/rewriteHandler.c
@@ -144,6 +144,13 @@ AcquireRewriteLocks(Query *parsetree, bool forUpdatePushedDown)
                    lockmode = AccessShareLock;
 
                rel = heap_open(rte->relid, lockmode);
+
+               /*
+                * While we have the relation open, update the RTE's relkind,
+                * just in case it changed since this rule was made.
+                */
+               rte->relkind = rel->rd_rel->relkind;
+
                heap_close(rel, NoLock);
                break;
 
@@ -1393,7 +1400,7 @@ markQueryForLocking(Query *qry, Node *jtnode,
        if (rte->rtekind == RTE_RELATION)
        {
            /* ignore foreign tables */
-           if (get_rel_relkind(rte->relid) != RELKIND_FOREIGN_TABLE)
+           if (rte->relkind != RELKIND_FOREIGN_TABLE)
            {
                applyLockingClause(qry, rti, forUpdate, noWait, pushedDown);
                rte->requiredPerms |= ACL_SELECT_FOR_UPDATE;

diff --git a/src/backend/utils/adt/ri_triggers.c b/src/backend/utils/adt/ri_triggers.c
index 5ef1563d1c95a47b823b5032d11351d81204ad8a..591d2eb16b00e643107f53a75ae6157df4cc6f83 100644 (file)
--- a/src/backend/utils/adt/ri_triggers.c
+++ b/src/backend/utils/adt/ri_triggers.c
@@ -2651,11 +2651,13 @@ RI_Initial_Check(Trigger *trigger, Relation fk_rel, Relation pk_rel)
    pkrte = makeNode(RangeTblEntry);
    pkrte->rtekind = RTE_RELATION;
    pkrte->relid = RelationGetRelid(pk_rel);
+   pkrte->relkind = pk_rel->rd_rel->relkind;
    pkrte->requiredPerms = ACL_SELECT;
 
    fkrte = makeNode(RangeTblEntry);
    fkrte->rtekind = RTE_RELATION;
    fkrte->relid = RelationGetRelid(fk_rel);
+   fkrte->relkind = fk_rel->rd_rel->relkind;
    fkrte->requiredPerms = ACL_SELECT;
 
    for (i = 0; i < riinfo.nkeys; i++)

diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index cd64235438e9f3b89a5e7eb40f08be09c4889a91..d9b359465a2fc96a10ee5b04ce3025da04473002 100644 (file)
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -628,6 +628,7 @@ pg_get_triggerdef_worker(Oid trigid, bool pretty)
    if (!isnull)
    {
        Node       *qual;
+       char        relkind;
        deparse_context context;
        deparse_namespace dpns;
        RangeTblEntry *oldrte;
@@ -637,10 +638,13 @@ pg_get_triggerdef_worker(Oid trigid, bool pretty)
 
        qual = stringToNode(TextDatumGetCString(value));
 
+       relkind = get_rel_relkind(trigrec->tgrelid);
+
        /* Build minimal OLD and NEW RTEs for the rel */
        oldrte = makeNode(RangeTblEntry);
        oldrte->rtekind = RTE_RELATION;
        oldrte->relid = trigrec->tgrelid;
+       oldrte->relkind = relkind;
        oldrte->eref = makeAlias("old", NIL);
        oldrte->inh = false;
        oldrte->inFromCl = true;
@@ -648,6 +652,7 @@ pg_get_triggerdef_worker(Oid trigid, bool pretty)
        newrte = makeNode(RangeTblEntry);
        newrte->rtekind = RTE_RELATION;
        newrte->relid = trigrec->tgrelid;
+       newrte->relkind = relkind;
        newrte->eref = makeAlias("new", NIL);
        newrte->inh = false;
        newrte->inFromCl = true;
@@ -2125,6 +2130,7 @@ deparse_context_for(const char *aliasname, Oid relid)
    rte = makeNode(RangeTblEntry);
    rte->rtekind = RTE_RELATION;
    rte->relid = relid;
+   rte->relkind = RELKIND_RELATION;    /* no need for exactness here */
    rte->eref = makeAlias(aliasname, NIL);
    rte->inh = false;
    rte->inFromCl = true;
@@ -4004,7 +4010,6 @@ get_name_for_var_field(Var *var, int fieldno,
    switch (rte->rtekind)
    {
        case RTE_RELATION:
-       case RTE_SPECIAL:
        case RTE_VALUES:
 
            /*

diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index 70106414cfe2b4e643a188de021657933cd12066..0a0544bc38aba4a930e33ef84e9e3e7ab23f3a5d 100644 (file)
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -53,6 +53,6 @@
  */
 
 /*                         yyyymmddN */
-#define CATALOG_VERSION_NO 201102221
+#define CATALOG_VERSION_NO 201102222
 
 #endif

diff --git a/src/include/catalog/pg_class.h b/src/include/catalog/pg_class.h
index 42bc8635a249558b4d70222ee70f6fa342a90fb1..e103530a3f24c582fd6643761e2cccdcffad3119 100644 (file)
--- a/src/include/catalog/pg_class.h
+++ b/src/include/catalog/pg_class.h
@@ -49,7 +49,7 @@ CATALOG(pg_class,1259) BKI_BOOTSTRAP BKI_ROWTYPE_OID(83) BKI_SCHEMA_MACRO
    Oid         reltoastidxid;  /* if toast table, OID of chunk_id index */
    bool        relhasindex;    /* T if has (or has had) any indexes */
    bool        relisshared;    /* T if shared across databases */
-   char        relpersistence; /* see RELPERSISTENCE_xxx constants */
+   char        relpersistence; /* see RELPERSISTENCE_xxx constants below */
    char        relkind;        /* see RELKIND_xxx constants below */
    int2        relnatts;       /* number of user attributes */
 
@@ -139,17 +139,18 @@ DESCR("");
 DATA(insert OID = 1259 (  pg_class     PGNSP 83 0 PGUID 0 0 0 0 0 0 0 f f p r 26 0 t f f f f 3 _null_ _null_ ));
 DESCR("");
 
+
+#define          RELKIND_RELATION        'r'       /* ordinary table */
 #define          RELKIND_INDEX           'i'       /* secondary index */
-#define          RELKIND_RELATION        'r'       /* ordinary cataloged heap */
-#define          RELKIND_SEQUENCE        'S'       /* SEQUENCE relation */
-#define          RELKIND_UNCATALOGED     'u'       /* temporary heap */
-#define          RELKIND_TOASTVALUE      't'       /* moved off huge values */
+#define          RELKIND_SEQUENCE        'S'       /* sequence object */
+#define          RELKIND_TOASTVALUE      't'       /* for out-of-line values */
 #define          RELKIND_VIEW            'v'       /* view */
 #define          RELKIND_COMPOSITE_TYPE  'c'       /* composite type */
 #define          RELKIND_FOREIGN_TABLE   'f'       /* foreign table */
+#define          RELKIND_UNCATALOGED     'u'       /* not yet cataloged */
 
-#define          RELPERSISTENCE_PERMANENT  'p'
-#define          RELPERSISTENCE_UNLOGGED   'u'
-#define          RELPERSISTENCE_TEMP       't'
+#define          RELPERSISTENCE_PERMANENT  'p'     /* regular table */
+#define          RELPERSISTENCE_UNLOGGED   'u'     /* unlogged permanent table */
+#define          RELPERSISTENCE_TEMP       't'     /* temporary table */
 
 #endif   /* PG_CLASS_H */

diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 63a61e3da248b2a1677d35eb56ff2b82b9c53b64..536c03245e3335da7b1d49e8cbb70d607fdbb387 100644 (file)
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -597,6 +597,9 @@ typedef struct XmlSerialize
  *   like outer joins and join-output-column aliasing.)  Other special
  *   RTE types also exist, as indicated by RTEKind.
  *
+ *   Note that we consider RTE_RELATION to cover anything that has a pg_class
+ *   entry.  relkind distinguishes the sub-cases.
+ *
  *   alias is an Alias node representing the AS alias-clause attached to the
  *   FROM expression, or NULL if no clause.
  *
@@ -643,7 +646,7 @@ typedef struct XmlSerialize
  *   indicates no permissions checking).  If checkAsUser is not zero,
  *   then do the permissions checks using the access rights of that user,
  *   not the current effective user ID.  (This allows rules to act as
- *   setuid gateways.)
+ *   setuid gateways.)  Permissions checks only apply to RELATION RTEs.
  *
  *   For SELECT/INSERT/UPDATE permissions, if the user doesn't have
  *   table-wide permissions then it is sufficient to have the permissions
@@ -660,7 +663,6 @@ typedef enum RTEKind
    RTE_RELATION,               /* ordinary relation reference */
    RTE_SUBQUERY,               /* subquery in FROM */
    RTE_JOIN,                   /* join */
-   RTE_SPECIAL,                /* special rule relation (NEW or OLD) */
    RTE_FUNCTION,               /* function in FROM */
    RTE_VALUES,                 /* VALUES (<exprlist>), (<exprlist>), ... */
    RTE_CTE                     /* common table expr (WITH list element) */
@@ -682,6 +684,7 @@ typedef struct RangeTblEntry
     * Fields valid for a plain relation RTE (else zero):
     */
    Oid         relid;          /* OID of the relation */
+   char        relkind;        /* relation kind (see pg_class.relkind) */
 
    /*
     * Fields valid for a subquery RTE (else NULL):