Fix INSERT ON CONFLICT UPDATE through a view that isn't just SELECT *.

When expanding an updatable view that is an INSERT's target, the rewriter
failed to rewrite Vars in the ON CONFLICT UPDATE clause.  This accidentally
worked if the view was just "SELECT * FROM ...", as the transformation
would be a no-op in that case.  With more complicated view targetlists,
this omission would often lead to "attribute ... has the wrong type" errors
or even crashes, as reported by Mario De Frutos Dieguez.

Fix by adding code to rewriteTargetView to fix up the data structure
correctly.  The easiest way to update the exclRelTlist list is to rebuild
it from scratch looking at the new target relation, so factor the code
for that out of transformOnConflictClause to make it sharable.

In passing, avoid duplicate permissions checks against the EXCLUDED
pseudo-relation, and prevent useless view expansion of that relation's
dummy RTE.  The latter is only known to happen (after this patch) in cases
where the query would fail later due to not having any INSTEAD OF triggers
for the view.  But by exactly that token, it would create an unintended
and very poorly tested state of the query data structure, so it seems like
a good idea to prevent it from happening at all.

This has been broken since ON CONFLICT was introduced, so back-patch
to 9.5.

Dean Rasheed, based on an earlier patch by Amit Langote;
comment-kibitzing and back-patching by me

Discussion: https://postgr.es/m/CAFYwGJ0xfzy8jaK80hVN2eUWr6huce0RU8AgU04MGD00igqkTg@mail.gmail.com

src/backend/parser/analyze.c

@@ -1022,9 +1022,6 @@ transformOnConflictClause(ParseState *pstate,
 	if (onConflictClause->action == ONCONFLICT_UPDATE)
 	{
 		Relation	targetrel = pstate->p_target_relation;
-		Var		   *var;
-		TargetEntry *te;
-		int			attno;
 
 		/*
 		 * All INSERT expressions have been parsed, get ready for potentially
@@ -1033,21 +1030,79 @@ transformOnConflictClause(ParseState *pstate,
 		pstate->p_is_insert = false;
 
 		/*
-		 * Add range table entry for the EXCLUDED pseudo relation; relkind is
+		 * Add range table entry for the EXCLUDED pseudo relation.  relkind is
 		 * set to composite to signal that we're not dealing with an actual
-		 * relation.
+		 * relation, and no permission checks are required on it.  (We'll
+		 * check the actual target relation, instead.)
 		 */
 		exclRte = addRangeTableEntryForRelation(pstate,
 												targetrel,
 												makeAlias("excluded", NIL),
 												false, false);
 		exclRte->relkind = RELKIND_COMPOSITE_TYPE;
+		exclRte->requiredPerms = 0;
+		/* other permissions fields in exclRte are already empty */
+
 		exclRelIndex = list_length(pstate->p_rtable);
 
+		/* Create EXCLUDED rel's targetlist for use by EXPLAIN */
+		exclRelTlist = BuildOnConflictExcludedTargetlist(targetrel,
+														 exclRelIndex);
+
 		/*
-		 * Build a targetlist representing the columns of the EXCLUDED pseudo
-		 * relation.  Have to be careful to use resnos that correspond to
-		 * attnos of the underlying relation.
+		 * Add EXCLUDED and the target RTE to the namespace, so that they can
+		 * be used in the UPDATE subexpressions.
+		 */
+		addRTEtoQuery(pstate, exclRte, false, true, true);
+		addRTEtoQuery(pstate, pstate->p_target_rangetblentry,
+					  false, true, true);
+
+		/*
+		 * Now transform the UPDATE subexpressions.
+		 */
+		onConflictSet =
+			transformUpdateTargetList(pstate, onConflictClause->targetList);
+
+		onConflictWhere = transformWhereClause(pstate,
+											   onConflictClause->whereClause,
+											   EXPR_KIND_WHERE, "WHERE");
+	}
+
+	/* Finally, build ON CONFLICT DO [NOTHING | UPDATE] expression */
+	result = makeNode(OnConflictExpr);
+
+	result->action = onConflictClause->action;
+	result->arbiterElems = arbiterElems;
+	result->arbiterWhere = arbiterWhere;
+	result->constraint = arbiterConstraint;
+	result->onConflictSet = onConflictSet;
+	result->onConflictWhere = onConflictWhere;
+	result->exclRelIndex = exclRelIndex;
+	result->exclRelTlist = exclRelTlist;
+
+	return result;
+}
+
+
+/*
+ * BuildOnConflictExcludedTargetlist
+ *		Create target list for the EXCLUDED pseudo-relation of ON CONFLICT,
+ *		representing the columns of targetrel with varno exclRelIndex.
+ *
+ * Note: Exported for use in the rewriter.
+ */
+List *
+BuildOnConflictExcludedTargetlist(Relation targetrel,
+								  Index exclRelIndex)
+{
+	List	   *result = NIL;
+	int			attno;
+	Var		   *var;
+	TargetEntry *te;
+
+	/*
+	 * Note that resnos of the tlist must correspond to attnos of the
+	 * underlying relation, hence we need entries for dropped columns too.
 	 */
 	for (attno = 0; attno < RelationGetNumberOfAttributes(targetrel); attno++)
 	{
@@ -1057,8 +1112,8 @@ transformOnConflictClause(ParseState *pstate,
 		if (attr->attisdropped)
 		{
 			/*
-				 * can't use atttypid here, but it doesn't really matter what
-				 * type the Const claims to be.
+			 * can't use atttypid here, but it doesn't really matter what type
+			 * the Const claims to be.
 			 */
 			var = (Var *) makeNullConst(INT4OID, -1, InvalidOid);
 			name = "";
@@ -1077,50 +1132,21 @@ transformOnConflictClause(ParseState *pstate,
 							 name,
 							 false);
 
-			/* don't require select access yet */
-			exclRelTlist = lappend(exclRelTlist, te);
+		result = lappend(result, te);
 	}
 
 	/*
-		 * Add a whole-row-Var entry to support references to "EXCLUDED.*".
-		 * Like the other entries in exclRelTlist, its resno must match the
-		 * Var's varattno, else the wrong things happen while resolving
-		 * references in setrefs.c.  This is against normal conventions for
-		 * targetlists, but it's okay since we don't use this as a real tlist.
+	 * Add a whole-row-Var entry to support references to "EXCLUDED.*".  Like
+	 * the other entries in the EXCLUDED tlist, its resno must match the Var's
+	 * varattno, else the wrong things happen while resolving references in
+	 * setrefs.c.  This is against normal conventions for targetlists, but
+	 * it's okay since we don't use this as a real tlist.
 	 */
 	var = makeVar(exclRelIndex, InvalidAttrNumber,
 				  targetrel->rd_rel->reltype,
 				  -1, InvalidOid, 0);
 	te = makeTargetEntry((Expr *) var, InvalidAttrNumber, NULL, true);
-		exclRelTlist = lappend(exclRelTlist, te);
-
-		/*
-		 * Add EXCLUDED and the target RTE to the namespace, so that they can
-		 * be used in the UPDATE statement.
-		 */
-		addRTEtoQuery(pstate, exclRte, false, true, true);
-		addRTEtoQuery(pstate, pstate->p_target_rangetblentry,
-					  false, true, true);
-
-		onConflictSet =
-			transformUpdateTargetList(pstate, onConflictClause->targetList);
-
-		onConflictWhere = transformWhereClause(pstate,
-											   onConflictClause->whereClause,
-											   EXPR_KIND_WHERE, "WHERE");
-	}
-
-	/* Finally, build ON CONFLICT DO [NOTHING | UPDATE] expression */
-	result = makeNode(OnConflictExpr);
-
-	result->action = onConflictClause->action;
-	result->arbiterElems = arbiterElems;
-	result->arbiterWhere = arbiterWhere;
-	result->constraint = arbiterConstraint;
-	result->onConflictSet = onConflictSet;
-	result->onConflictWhere = onConflictWhere;
-	result->exclRelIndex = exclRelIndex;
-	result->exclRelTlist = exclRelTlist;
+	result = lappend(result, te);
 
 	return result;
 }

src/backend/rewrite/rewriteHandler.c

@@ -29,6 +29,7 @@
 #include "nodes/nodeFuncs.h"
 #include "parser/analyze.h"
 #include "parser/parse_coerce.h"
+#include "parser/parse_relation.h"
 #include "parser/parsetree.h"
 #include "rewrite/rewriteDefine.h"
 #include "rewrite/rewriteHandler.h"
@@ -1770,6 +1771,17 @@ fireRIRrules(Query *parsetree, List *activeRIRs)
 		if (rte->relkind == RELKIND_MATVIEW)
 			continue;
 
+		/*
+		 * In INSERT ... ON CONFLICT, ignore the EXCLUDED pseudo-relation;
+		 * even if it points to a view, we needn't expand it, and should not
+		 * because we want the RTE to remain of RTE_RELATION type.  Otherwise,
+		 * it would get changed to RTE_SUBQUERY type, which is an
+		 * untested/unsupported situation.
+		 */
+		if (parsetree->onConflict &&
+			rt_index == parsetree->onConflict->exclRelIndex)
+			continue;
+
 		/*
 		 * If the table is not referenced in the query, then we ignore it.
 		 * This prevents infinite expansion loop due to new rtable entries
@@ -2875,8 +2887,6 @@ rewriteTargetView(Query *parsetree, Relation view)
 	 */
 	base_rte->relkind = base_rel->rd_rel->relkind;
 
-	heap_close(base_rel, NoLock);
-
 	/*
 	 * If the view query contains any sublink subqueries then we need to also
 	 * acquire locks on any relations they refer to.  We know that there won't
@@ -3034,6 +3044,93 @@ rewriteTargetView(Query *parsetree, Relation view)
 		}
 	}
 
+	/*
+	 * For INSERT .. ON CONFLICT .. DO UPDATE, we must also update assorted
+	 * stuff in the onConflict data structure.
+	 */
+	if (parsetree->onConflict &&
+		parsetree->onConflict->action == ONCONFLICT_UPDATE)
+	{
+		Index		old_exclRelIndex,
+					new_exclRelIndex;
+		RangeTblEntry *new_exclRte;
+		List	   *tmp_tlist;
+
+		/*
+		 * Like the INSERT/UPDATE code above, update the resnos in the
+		 * auxiliary UPDATE targetlist to refer to columns of the base
+		 * relation.
+		 */
+		foreach(lc, parsetree->onConflict->onConflictSet)
+		{
+			TargetEntry *tle = (TargetEntry *) lfirst(lc);
+			TargetEntry *view_tle;
+
+			if (tle->resjunk)
+				continue;
+
+			view_tle = get_tle_by_resno(view_targetlist, tle->resno);
+			if (view_tle != NULL && !view_tle->resjunk && IsA(view_tle->expr, Var))
+				tle->resno = ((Var *) view_tle->expr)->varattno;
+			else
+				elog(ERROR, "attribute number %d not found in view targetlist",
+					 tle->resno);
+		}
+
+		/*
+		 * Also, create a new RTE for the EXCLUDED pseudo-relation, using the
+		 * query's new base rel (which may well have a different column list
+		 * from the view, hence we need a new column alias list).  This should
+		 * match transformOnConflictClause.  In particular, note that the
+		 * relkind is set to composite to signal that we're not dealing with
+		 * an actual relation, and no permissions checks are wanted.
+		 */
+		old_exclRelIndex = parsetree->onConflict->exclRelIndex;
+
+		new_exclRte = addRangeTableEntryForRelation(make_parsestate(NULL),
+													base_rel,
+													makeAlias("excluded",
+															  NIL),
+													false, false);
+		new_exclRte->relkind = RELKIND_COMPOSITE_TYPE;
+		new_exclRte->requiredPerms = 0;
+		/* other permissions fields in new_exclRte are already empty */
+
+		parsetree->rtable = lappend(parsetree->rtable, new_exclRte);
+		new_exclRelIndex = parsetree->onConflict->exclRelIndex =
+			list_length(parsetree->rtable);
+
+		/*
+		 * Replace the targetlist for the EXCLUDED pseudo-relation with a new
+		 * one, representing the columns from the new base relation.
+		 */
+		parsetree->onConflict->exclRelTlist =
+			BuildOnConflictExcludedTargetlist(base_rel, new_exclRelIndex);
+
+		/*
+		 * Update all Vars in the ON CONFLICT clause that refer to the old
+		 * EXCLUDED pseudo-relation.  We want to use the column mappings
+		 * defined in the view targetlist, but we need the outputs to refer to
+		 * the new EXCLUDED pseudo-relation rather than the new target RTE.
+		 * Also notice that "EXCLUDED.*" will be expanded using the view's
+		 * rowtype, which seems correct.
+		 */
+		tmp_tlist = copyObject(view_targetlist);
+
+		ChangeVarNodes((Node *) tmp_tlist, new_rt_index,
+					   new_exclRelIndex, 0);
+
+		parsetree->onConflict = (OnConflictExpr *)
+			ReplaceVarsFromTargetList((Node *) parsetree->onConflict,
+									  old_exclRelIndex,
+									  0,
+									  view_rte,
+									  tmp_tlist,
+									  REPLACEVARS_REPORT_ERROR,
+									  0,
+									  &parsetree->hasSubLinks);
+	}
+
 	/*
 	 * For UPDATE/DELETE, pull up any WHERE quals from the view.  We know that
 	 * any Vars in the quals must reference the one base relation, so we need
@@ -3161,6 +3258,8 @@ rewriteTargetView(Query *parsetree, Relation view)
 		}
 	}
 
+	heap_close(base_rel, NoLock);
+
 	return parsetree;
 }
 

src/include/parser/analyze.h

@@ -43,4 +43,7 @@ extern void applyLockingClause(Query *qry, Index rtindex,
 				   LockClauseStrength strength,
 				   LockWaitPolicy waitPolicy, bool pushedDown);
 
+extern List *BuildOnConflictExcludedTargetlist(Relation targetrel,
+								  Index exclRelIndex);
+
 #endif							/* ANALYZE_H */

src/test/regress/expected/updatable_views.out

@@ -2578,3 +2578,197 @@ ERROR:  new row violates check option for view "wcowrtest_v2"
 DETAIL:  Failing row contains (2, no such row in sometable).
 drop view wcowrtest_v, wcowrtest_v2;
 drop table wcowrtest, sometable;
+-- Check INSERT .. ON CONFLICT DO UPDATE works correctly when the view's
+-- columns are named and ordered differently than the underlying table's.
+create table uv_iocu_tab (a text unique, b float);
+insert into uv_iocu_tab values ('xyxyxy', 0);
+create view uv_iocu_view as
+   select b, b+1 as c, a, '2.0'::text as two from uv_iocu_tab;
+insert into uv_iocu_view (a, b) values ('xyxyxy', 1)
+   on conflict (a) do update set b = uv_iocu_view.b;
+select * from uv_iocu_tab;
+   a    | b 
+--------+---
+ xyxyxy | 0
+(1 row)
+
+insert into uv_iocu_view (a, b) values ('xyxyxy', 1)
+   on conflict (a) do update set b = excluded.b;
+select * from uv_iocu_tab;
+   a    | b 
+--------+---
+ xyxyxy | 1
+(1 row)
+
+-- OK to access view columns that are not present in underlying base
+-- relation in the ON CONFLICT portion of the query
+insert into uv_iocu_view (a, b) values ('xyxyxy', 3)
+   on conflict (a) do update set b = cast(excluded.two as float);
+select * from uv_iocu_tab;
+   a    | b 
+--------+---
+ xyxyxy | 2
+(1 row)
+
+explain (costs off)
+insert into uv_iocu_view (a, b) values ('xyxyxy', 3)
+   on conflict (a) do update set b = excluded.b where excluded.c > 0;
+                                    QUERY PLAN                                     
+-----------------------------------------------------------------------------------
+ Insert on uv_iocu_tab
+   Conflict Resolution: UPDATE
+   Conflict Arbiter Indexes: uv_iocu_tab_a_key
+   Conflict Filter: ((excluded.b + '1'::double precision) > '0'::double precision)
+   ->  Result
+(5 rows)
+
+insert into uv_iocu_view (a, b) values ('xyxyxy', 3)
+   on conflict (a) do update set b = excluded.b where excluded.c > 0;
+select * from uv_iocu_tab;
+   a    | b 
+--------+---
+ xyxyxy | 3
+(1 row)
+
+drop view uv_iocu_view;
+drop table uv_iocu_tab;
+-- Test whole-row references to the view
+create table uv_iocu_tab (a int unique, b text);
+create view uv_iocu_view as
+    select b as bb, a as aa, uv_iocu_tab::text as cc from uv_iocu_tab;
+insert into uv_iocu_view (aa,bb) values (1,'x');
+explain (costs off)
+insert into uv_iocu_view (aa,bb) values (1,'y')
+   on conflict (aa) do update set bb = 'Rejected: '||excluded.*
+   where excluded.aa > 0
+   and excluded.bb != ''
+   and excluded.cc is not null;
+                                               QUERY PLAN                                                
+---------------------------------------------------------------------------------------------------------
+ Insert on uv_iocu_tab
+   Conflict Resolution: UPDATE
+   Conflict Arbiter Indexes: uv_iocu_tab_a_key
+   Conflict Filter: ((excluded.a > 0) AND (excluded.b <> ''::text) AND ((excluded.*)::text IS NOT NULL))
+   ->  Result
+(5 rows)
+
+insert into uv_iocu_view (aa,bb) values (1,'y')
+   on conflict (aa) do update set bb = 'Rejected: '||excluded.*
+   where excluded.aa > 0
+   and excluded.bb != ''
+   and excluded.cc is not null;
+select * from uv_iocu_view;
+           bb            | aa |               cc                
+-------------------------+----+---------------------------------
+ Rejected: (y,1,"(1,y)") |  1 | (1,"Rejected: (y,1,""(1,y)"")")
+(1 row)
+
+-- Test omitting a column of the base relation
+delete from uv_iocu_view;
+insert into uv_iocu_view (aa,bb) values (1,'x');
+insert into uv_iocu_view (aa) values (1)
+   on conflict (aa) do update set bb = 'Rejected: '||excluded.*;
+select * from uv_iocu_view;
+          bb           | aa |              cc               
+-----------------------+----+-------------------------------
+ Rejected: (,1,"(1,)") |  1 | (1,"Rejected: (,1,""(1,)"")")
+(1 row)
+
+alter table uv_iocu_tab alter column b set default 'table default';
+insert into uv_iocu_view (aa) values (1)
+   on conflict (aa) do update set bb = 'Rejected: '||excluded.*;
+select * from uv_iocu_view;
+                          bb                           | aa |                                 cc                                  
+-------------------------------------------------------+----+---------------------------------------------------------------------
+ Rejected: ("table default",1,"(1,""table default"")") |  1 | (1,"Rejected: (""table default"",1,""(1,""""table default"""")"")")
+(1 row)
+
+alter view uv_iocu_view alter column bb set default 'view default';
+insert into uv_iocu_view (aa) values (1)
+   on conflict (aa) do update set bb = 'Rejected: '||excluded.*;
+select * from uv_iocu_view;
+                         bb                          | aa |                                cc                                 
+-----------------------------------------------------+----+-------------------------------------------------------------------
+ Rejected: ("view default",1,"(1,""view default"")") |  1 | (1,"Rejected: (""view default"",1,""(1,""""view default"""")"")")
+(1 row)
+
+-- Should fail to update non-updatable columns
+insert into uv_iocu_view (aa) values (1)
+   on conflict (aa) do update set cc = 'XXX';
+ERROR:  cannot insert into column "cc" of view "uv_iocu_view"
+DETAIL:  View columns that are not columns of their base relation are not updatable.
+drop view uv_iocu_view;
+drop table uv_iocu_tab;
+-- ON CONFLICT DO UPDATE permissions checks
+create user regress_view_user1;
+create user regress_view_user2;
+set session authorization regress_view_user1;
+create table base_tbl(a int unique, b text, c float);
+insert into base_tbl values (1,'xxx',1.0);
+create view rw_view1 as select b as bb, c as cc, a as aa from base_tbl;
+grant select (aa,bb) on rw_view1 to regress_view_user2;
+grant insert on rw_view1 to regress_view_user2;
+grant update (bb) on rw_view1 to regress_view_user2;
+set session authorization regress_view_user2;
+insert into rw_view1 values ('yyy',2.0,1)
+  on conflict (aa) do update set bb = excluded.cc; -- Not allowed
+ERROR:  permission denied for view rw_view1
+insert into rw_view1 values ('yyy',2.0,1)
+  on conflict (aa) do update set bb = rw_view1.cc; -- Not allowed
+ERROR:  permission denied for view rw_view1
+insert into rw_view1 values ('yyy',2.0,1)
+  on conflict (aa) do update set bb = excluded.bb; -- OK
+insert into rw_view1 values ('zzz',2.0,1)
+  on conflict (aa) do update set bb = rw_view1.bb||'xxx'; -- OK
+insert into rw_view1 values ('zzz',2.0,1)
+  on conflict (aa) do update set cc = 3.0; -- Not allowed
+ERROR:  permission denied for view rw_view1
+reset session authorization;
+select * from base_tbl;
+ a |   b    | c 
+---+--------+---
+ 1 | yyyxxx | 1
+(1 row)
+
+set session authorization regress_view_user1;
+grant select (a,b) on base_tbl to regress_view_user2;
+grant insert (a,b) on base_tbl to regress_view_user2;
+grant update (a,b) on base_tbl to regress_view_user2;
+set session authorization regress_view_user2;
+create view rw_view2 as select b as bb, c as cc, a as aa from base_tbl;
+insert into rw_view2 (aa,bb) values (1,'xxx')
+  on conflict (aa) do update set bb = excluded.bb; -- Not allowed
+ERROR:  permission denied for table base_tbl
+create view rw_view3 as select b as bb, a as aa from base_tbl;
+insert into rw_view3 (aa,bb) values (1,'xxx')
+  on conflict (aa) do update set bb = excluded.bb; -- OK
+reset session authorization;
+select * from base_tbl;
+ a |  b  | c 
+---+-----+---
+ 1 | xxx | 1
+(1 row)
+
+set session authorization regress_view_user2;
+create view rw_view4 as select aa, bb, cc FROM rw_view1;
+insert into rw_view4 (aa,bb) values (1,'yyy')
+  on conflict (aa) do update set bb = excluded.bb; -- Not allowed
+ERROR:  permission denied for view rw_view1
+create view rw_view5 as select aa, bb FROM rw_view1;
+insert into rw_view5 (aa,bb) values (1,'yyy')
+  on conflict (aa) do update set bb = excluded.bb; -- OK
+reset session authorization;
+select * from base_tbl;
+ a |  b  | c 
+---+-----+---
+ 1 | yyy | 1
+(1 row)
+
+drop view rw_view5;
+drop view rw_view4;
+drop view rw_view3;
+drop view rw_view2;
+drop view rw_view1;
+drop table base_tbl;
+drop user regress_view_user1;
+drop user regress_view_user2;

src/test/regress/sql/updatable_views.sql

@@ -1244,3 +1244,138 @@ insert into wcowrtest_v2 values (2, 'no such row in sometable');
 
 drop view wcowrtest_v, wcowrtest_v2;
 drop table wcowrtest, sometable;
+
+-- Check INSERT .. ON CONFLICT DO UPDATE works correctly when the view's
+-- columns are named and ordered differently than the underlying table's.
+create table uv_iocu_tab (a text unique, b float);
+insert into uv_iocu_tab values ('xyxyxy', 0);
+create view uv_iocu_view as
+   select b, b+1 as c, a, '2.0'::text as two from uv_iocu_tab;
+
+insert into uv_iocu_view (a, b) values ('xyxyxy', 1)
+   on conflict (a) do update set b = uv_iocu_view.b;
+select * from uv_iocu_tab;
+insert into uv_iocu_view (a, b) values ('xyxyxy', 1)
+   on conflict (a) do update set b = excluded.b;
+select * from uv_iocu_tab;
+
+-- OK to access view columns that are not present in underlying base
+-- relation in the ON CONFLICT portion of the query
+insert into uv_iocu_view (a, b) values ('xyxyxy', 3)
+   on conflict (a) do update set b = cast(excluded.two as float);
+select * from uv_iocu_tab;
+
+explain (costs off)
+insert into uv_iocu_view (a, b) values ('xyxyxy', 3)
+   on conflict (a) do update set b = excluded.b where excluded.c > 0;
+
+insert into uv_iocu_view (a, b) values ('xyxyxy', 3)
+   on conflict (a) do update set b = excluded.b where excluded.c > 0;
+select * from uv_iocu_tab;
+
+drop view uv_iocu_view;
+drop table uv_iocu_tab;
+
+-- Test whole-row references to the view
+create table uv_iocu_tab (a int unique, b text);
+create view uv_iocu_view as
+    select b as bb, a as aa, uv_iocu_tab::text as cc from uv_iocu_tab;
+
+insert into uv_iocu_view (aa,bb) values (1,'x');
+explain (costs off)
+insert into uv_iocu_view (aa,bb) values (1,'y')
+   on conflict (aa) do update set bb = 'Rejected: '||excluded.*
+   where excluded.aa > 0
+   and excluded.bb != ''
+   and excluded.cc is not null;
+insert into uv_iocu_view (aa,bb) values (1,'y')
+   on conflict (aa) do update set bb = 'Rejected: '||excluded.*
+   where excluded.aa > 0
+   and excluded.bb != ''
+   and excluded.cc is not null;
+select * from uv_iocu_view;
+
+-- Test omitting a column of the base relation
+delete from uv_iocu_view;
+insert into uv_iocu_view (aa,bb) values (1,'x');
+insert into uv_iocu_view (aa) values (1)
+   on conflict (aa) do update set bb = 'Rejected: '||excluded.*;
+select * from uv_iocu_view;
+
+alter table uv_iocu_tab alter column b set default 'table default';
+insert into uv_iocu_view (aa) values (1)
+   on conflict (aa) do update set bb = 'Rejected: '||excluded.*;
+select * from uv_iocu_view;
+
+alter view uv_iocu_view alter column bb set default 'view default';
+insert into uv_iocu_view (aa) values (1)
+   on conflict (aa) do update set bb = 'Rejected: '||excluded.*;
+select * from uv_iocu_view;
+
+-- Should fail to update non-updatable columns
+insert into uv_iocu_view (aa) values (1)
+   on conflict (aa) do update set cc = 'XXX';
+
+drop view uv_iocu_view;
+drop table uv_iocu_tab;
+
+-- ON CONFLICT DO UPDATE permissions checks
+create user regress_view_user1;
+create user regress_view_user2;
+
+set session authorization regress_view_user1;
+create table base_tbl(a int unique, b text, c float);
+insert into base_tbl values (1,'xxx',1.0);
+create view rw_view1 as select b as bb, c as cc, a as aa from base_tbl;
+
+grant select (aa,bb) on rw_view1 to regress_view_user2;
+grant insert on rw_view1 to regress_view_user2;
+grant update (bb) on rw_view1 to regress_view_user2;
+
+set session authorization regress_view_user2;
+insert into rw_view1 values ('yyy',2.0,1)
+  on conflict (aa) do update set bb = excluded.cc; -- Not allowed
+insert into rw_view1 values ('yyy',2.0,1)
+  on conflict (aa) do update set bb = rw_view1.cc; -- Not allowed
+insert into rw_view1 values ('yyy',2.0,1)
+  on conflict (aa) do update set bb = excluded.bb; -- OK
+insert into rw_view1 values ('zzz',2.0,1)
+  on conflict (aa) do update set bb = rw_view1.bb||'xxx'; -- OK
+insert into rw_view1 values ('zzz',2.0,1)
+  on conflict (aa) do update set cc = 3.0; -- Not allowed
+reset session authorization;
+select * from base_tbl;
+
+set session authorization regress_view_user1;
+grant select (a,b) on base_tbl to regress_view_user2;
+grant insert (a,b) on base_tbl to regress_view_user2;
+grant update (a,b) on base_tbl to regress_view_user2;
+
+set session authorization regress_view_user2;
+create view rw_view2 as select b as bb, c as cc, a as aa from base_tbl;
+insert into rw_view2 (aa,bb) values (1,'xxx')
+  on conflict (aa) do update set bb = excluded.bb; -- Not allowed
+create view rw_view3 as select b as bb, a as aa from base_tbl;
+insert into rw_view3 (aa,bb) values (1,'xxx')
+  on conflict (aa) do update set bb = excluded.bb; -- OK
+reset session authorization;
+select * from base_tbl;
+
+set session authorization regress_view_user2;
+create view rw_view4 as select aa, bb, cc FROM rw_view1;
+insert into rw_view4 (aa,bb) values (1,'yyy')
+  on conflict (aa) do update set bb = excluded.bb; -- Not allowed
+create view rw_view5 as select aa, bb FROM rw_view1;
+insert into rw_view5 (aa,bb) values (1,'yyy')
+  on conflict (aa) do update set bb = excluded.bb; -- OK
+reset session authorization;
+select * from base_tbl;
+
+drop view rw_view5;
+drop view rw_view4;
+drop view rw_view3;
+drop view rw_view2;
+drop view rw_view1;
+drop table base_tbl;
+drop user regress_view_user1;
+drop user regress_view_user2;