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, 15 insertions, 11 deletions

diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index 70106414cfe..0a0544bc38a 100644
--- 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 42bc8635a24..e103530a3f2 100644
--- 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 63a61e3da24..536c03245e3 100644
--- 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):