1 files changed, 107 insertions, 0 deletions
diff --git a/src/backend/commands/view.c b/src/backend/commands/view.c
index ff98c773f55..0bacb819e52 100644
--- a/src/backend/commands/view.c
+++ b/src/backend/commands/view.c
@@ -353,6 +353,107 @@ DefineViewRules(Oid viewOid, Query *viewParse, bool replace)
 	 */
 }
 
+/*---------------------------------------------------------------
+ * UpdateRangeTableOfViewParse
+ *
+ * Update the range table of the given parsetree.
+ * This update consists of adding two new entries IN THE BEGINNING
+ * of the range table (otherwise the rule system will die a slow,
+ * horrible and painful death, and we do not want that now, do we?)
+ * one for the OLD relation and one for the NEW one (both of
+ * them refer in fact to the "view" relation).
+ *
+ * Of course we must also increase the 'varnos' of all the Var nodes
+ * by 2...
+ *
+ * These extra RT entries are not actually used in the query,
+ * except for run-time locking.
+ *---------------------------------------------------------------
+ */
+static Query *
+UpdateRangeTableOfViewParse(Oid viewOid, Query *viewParse)
+{
+	Relation	viewRel;
+	List	   *new_rt;
+	ParseNamespaceItem *nsitem;
+	RangeTblEntry *rt_entry1,
+			   *rt_entry2;
+	RTEPermissionInfo *rte_perminfo1;
+	ParseState *pstate;
+	ListCell   *lc;
+
+	/*
+	 * Make a copy of the given parsetree.  It's not so much that we don't
+	 * want to scribble on our input, it's that the parser has a bad habit of
+	 * outputting multiple links to the same subtree for constructs like
+	 * BETWEEN, and we mustn't have OffsetVarNodes increment the varno of a
+	 * Var node twice.  copyObject will expand any multiply-referenced subtree
+	 * into multiple copies.
+	 */
+	viewParse = copyObject(viewParse);
+
+	/* Create a dummy ParseState for addRangeTableEntryForRelation */
+	pstate = make_parsestate(NULL);
+
+	/* need to open the rel for addRangeTableEntryForRelation */
+	viewRel = relation_open(viewOid, AccessShareLock);
+
+	/*
+	 * Create the 2 new range table entries and form the new range table...
+	 * OLD first, then NEW....
+	 */
+	nsitem = addRangeTableEntryForRelation(pstate, viewRel,
+										   AccessShareLock,
+										   makeAlias("old", NIL),
+										   false, false);
+	rt_entry1 = nsitem->p_rte;
+	rte_perminfo1 = nsitem->p_perminfo;
+	nsitem = addRangeTableEntryForRelation(pstate, viewRel,
+										   AccessShareLock,
+										   makeAlias("new", NIL),
+										   false, false);
+	rt_entry2 = nsitem->p_rte;
+
+	/*
+	 * Add only the "old" RTEPermissionInfo at the head of view query's list
+	 * and update the other RTEs' perminfoindex accordingly.  When rewriting a
+	 * query on the view, ApplyRetrieveRule() will transfer the view
+	 * relation's permission details into this RTEPermissionInfo.  That's
+	 * needed because the view's RTE itself will be transposed into a subquery
+	 * RTE that can't carry the permission details; see the code stanza toward
+	 * the end of ApplyRetrieveRule() for how that's done.
+	 */
+	viewParse->rteperminfos = lcons(rte_perminfo1, viewParse->rteperminfos);
+	foreach(lc, viewParse->rtable)
+	{
+		RangeTblEntry *rte = lfirst(lc);
+
+		if (rte->perminfoindex > 0)
+			rte->perminfoindex += 1;
+	}
+
+	/*
+	 * Also make the "new" RTE's RTEPermissionInfo undiscoverable.  This is a
+	 * bit of a hack given that all the non-child RTE_RELATION entries really
+	 * should have a RTEPermissionInfo, but this dummy "new" RTE is going to
+	 * go away anyway in the very near future.
+	 */
+	rt_entry2->perminfoindex = 0;
+
+	new_rt = lcons(rt_entry1, lcons(rt_entry2, viewParse->rtable));
+
+	viewParse->rtable = new_rt;
+
+	/*
+	 * Now offset all var nodes by 2, and jointree RT indexes too.
+	 */
+	OffsetVarNodes((Node *) viewParse, 2, 0);
+
+	relation_close(viewRel, AccessShareLock);
+
+	return viewParse;
+}
+
 /*
  * DefineView
  *		Execute a CREATE VIEW command.
@@ -516,6 +617,12 @@ void
 StoreViewQuery(Oid viewOid, Query *viewParse, bool replace)
 {
 	/*
+	 * The range table of 'viewParse' does not contain entries for the "OLD"
+	 * and "NEW" relations. So... add them!
+	 */
+	viewParse = UpdateRangeTableOfViewParse(viewOid, viewParse);
+
+	/*
 	 * Now create the rules associated with the view.
 	 */
 	DefineViewRules(viewOid, viewParse, replace);