Merge branch 'master' into bug6123bug6123

17 files changed, 442 insertions, 271 deletions

diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index e2e2abe4d3..db97df13c4 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -954,7 +954,7 @@ testdb=>
 
 
       <varlistentry>
-        <term><literal>\dc[S] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
+        <term><literal>\dc[S+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
         <listitem>
         <para>
         Lists conversions between character-set encodings.
@@ -964,6 +964,8 @@ testdb=&gt;
         By default, only user-created objects are shown;  supply a
         pattern or the <literal>S</literal> modifier to include system
         objects.
+        If <literal>+</literal> is appended to the command name, each object
+        is listed with its associated description.
         </para>
         </listitem>
       </varlistentry>
@@ -977,6 +979,8 @@ testdb=&gt;
         If <replaceable class="parameter">pattern</replaceable>
         is specified, only casts whose source or target types match the
         pattern are listed.
+        If <literal>+</literal> is appended to the command name, each object
+        is listed with its associated description.
         </para>
         </listitem>
       </varlistentry>
@@ -1038,7 +1042,7 @@ testdb=&gt;
 
 
       <varlistentry>
-        <term><literal>\dD[S] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
+        <term><literal>\dD[S+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
         <listitem>
         <para>
         Lists domains. If <replaceable
@@ -1047,6 +1051,8 @@ testdb=&gt;
         By default, only user-created objects are shown;  supply a
         pattern or the <literal>S</literal> modifier to include system
         objects.
+        If <literal>+</literal> is appended to the command name, each object
+        is listed with its associated description.
         </para>
         </listitem>
       </varlistentry>
@@ -1092,7 +1098,7 @@ testdb=&gt;
         specified, only those servers whose name matches the pattern
         are listed.  If the form <literal>\des+</literal> is used, a
         full description of each server is shown, including the
-        server's ACL, type, version, and options.
+        server's ACL, type, version, options, and description.
         </para>
         </listitem>
       </varlistentry>
@@ -1106,7 +1112,8 @@ testdb=&gt;
         If <replaceable class="parameter">pattern</replaceable> is
         specified, only entries whose table name or schema name matches
         the pattern are listed.  If the form <literal>\det+</literal>
-        is used, generic options are also displayed.
+        is used, generic options and the foreign table description
+        are also displayed.
         </para>
         </listitem>
       </varlistentry>
@@ -1144,8 +1151,8 @@ testdb=&gt;
         If <replaceable class="parameter">pattern</replaceable> is
         specified, only those foreign-data wrappers whose name matches
         the pattern are listed.  If the form <literal>\dew+</literal>
-        is used, the ACL and options of the foreign-data wrapper are
-        also shown.
+        is used, the ACL, options, and description of the foreign-data
+        wrapper are also shown.
         </para>
         </listitem>
       </varlistentry>
diff --git a/src/backend/access/common/reloptions.c b/src/backend/access/common/reloptions.c
index 465742556f..900b222865 100644
--- a/src/backend/access/common/reloptions.c
+++ b/src/backend/access/common/reloptions.c
@@ -371,8 +371,6 @@ allocate_reloption(bits32 kinds, int type, char *name, char *desc)
 	size_t		size;
 	relopt_gen *newoption;
 
-	Assert(type != RELOPT_TYPE_STRING);
-
 	oldcxt = MemoryContextSwitchTo(TopMemoryContext);
 
 	switch (type)
@@ -386,6 +384,9 @@ allocate_reloption(bits32 kinds, int type, char *name, char *desc)
 		case RELOPT_TYPE_REAL:
 			size = sizeof(relopt_real);
 			break;
+		case RELOPT_TYPE_STRING:
+			size = sizeof(relopt_string);
+			break;
 		default:
 			elog(ERROR, "unsupported option type");
 			return NULL;		/* keep compiler quiet */
@@ -474,45 +475,29 @@ void
 add_string_reloption(bits32 kinds, char *name, char *desc, char *default_val,
 					 validate_string_relopt validator)
 {
-	MemoryContext oldcxt;
 	relopt_string *newoption;
-	int			default_len = 0;
-
-	oldcxt = MemoryContextSwitchTo(TopMemoryContext);
-
-	if (default_val)
-		default_len = strlen(default_val);
 
-	newoption = palloc0(sizeof(relopt_string) + default_len);
+	/* make sure the validator/default combination is sane */
+	if (validator)
+		(validator) (default_val);
 
-	newoption->gen.name = pstrdup(name);
-	if (desc)
-		newoption->gen.desc = pstrdup(desc);
-	else
-		newoption->gen.desc = NULL;
-	newoption->gen.kinds = kinds;
-	newoption->gen.namelen = strlen(name);
-	newoption->gen.type = RELOPT_TYPE_STRING;
+	newoption = (relopt_string *) allocate_reloption(kinds, RELOPT_TYPE_STRING,
+													 name, desc);
 	newoption->validate_cb = validator;
 	if (default_val)
 	{
-		strcpy(newoption->default_val, default_val);
-		newoption->default_len = default_len;
+		newoption->default_val = MemoryContextStrdup(TopMemoryContext,
+													 default_val);
+		newoption->default_len = strlen(default_val);
 		newoption->default_isnull = false;
 	}
 	else
 	{
-		newoption->default_val[0] = '\0';
+		newoption->default_val = "";
 		newoption->default_len = 0;
 		newoption->default_isnull = true;
 	}
 
-	/* make sure the validator/default combination is sane */
-	if (newoption->validate_cb)
-		(newoption->validate_cb) (newoption->default_val);
-
-	MemoryContextSwitchTo(oldcxt);
-
 	add_reloption((relopt_gen *) newoption);
 }
 
diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c
index bb38768bd4..1b264a29e2 100644
--- a/src/backend/optimizer/path/costsize.c
+++ b/src/backend/optimizer/path/costsize.c
@@ -3491,7 +3491,7 @@ set_rel_width(PlannerInfo *root, RelOptInfo *rel)
 		else if (IsA(node, PlaceHolderVar))
 		{
 			PlaceHolderVar *phv = (PlaceHolderVar *) node;
-			PlaceHolderInfo *phinfo = find_placeholder_info(root, phv);
+			PlaceHolderInfo *phinfo = find_placeholder_info(root, phv, false);
 
 			tuple_width += phinfo->ph_width;
 		}
diff --git a/src/backend/optimizer/path/equivclass.c b/src/backend/optimizer/path/equivclass.c
index f2beb410e7..acc4fb1a18 100644
--- a/src/backend/optimizer/path/equivclass.c
+++ b/src/backend/optimizer/path/equivclass.c
@@ -850,7 +850,7 @@ generate_base_implied_equalities_no_const(PlannerInfo *root,
 										   PVC_RECURSE_AGGREGATES,
 										   PVC_INCLUDE_PLACEHOLDERS);
 
-		add_vars_to_targetlist(root, vars, ec->ec_relids);
+		add_vars_to_targetlist(root, vars, ec->ec_relids, false);
 		list_free(vars);
 	}
 }
diff --git a/src/backend/optimizer/plan/initsplan.c b/src/backend/optimizer/plan/initsplan.c
index 394cda32e5..9cfc56ea54 100644
--- a/src/backend/optimizer/plan/initsplan.c
+++ b/src/backend/optimizer/plan/initsplan.c
@@ -137,7 +137,7 @@ build_base_rel_tlists(PlannerInfo *root, List *final_tlist)
 
 	if (tlist_vars != NIL)
 	{
-		add_vars_to_targetlist(root, tlist_vars, bms_make_singleton(0));
+		add_vars_to_targetlist(root, tlist_vars, bms_make_singleton(0), true);
 		list_free(tlist_vars);
 	}
 }
@@ -151,10 +151,15 @@ build_base_rel_tlists(PlannerInfo *root, List *final_tlist)
  *
  *	  The list may also contain PlaceHolderVars.  These don't necessarily
  *	  have a single owning relation; we keep their attr_needed info in
- *	  root->placeholder_list instead.
+ *	  root->placeholder_list instead.  If create_new_ph is true, it's OK
+ *	  to create new PlaceHolderInfos, and we also have to update ph_may_need;
+ *	  otherwise, the PlaceHolderInfos must already exist, and we should only
+ *	  update their ph_needed.  (It should be true before deconstruct_jointree
+ *	  begins, and false after that.)
  */
 void
-add_vars_to_targetlist(PlannerInfo *root, List *vars, Relids where_needed)
+add_vars_to_targetlist(PlannerInfo *root, List *vars,
+					   Relids where_needed, bool create_new_ph)
 {
 	ListCell   *temp;
 
@@ -185,18 +190,20 @@ add_vars_to_targetlist(PlannerInfo *root, List *vars, Relids where_needed)
 		else if (IsA(node, PlaceHolderVar))
 		{
 			PlaceHolderVar *phv = (PlaceHolderVar *) node;
-			PlaceHolderInfo *phinfo = find_placeholder_info(root, phv);
+			PlaceHolderInfo *phinfo = find_placeholder_info(root, phv,
+															create_new_ph);
 
+			/* Always adjust ph_needed */
 			phinfo->ph_needed = bms_add_members(phinfo->ph_needed,
 												where_needed);
 
 			/*
-			 * Update ph_may_need too.	This is currently only necessary when
-			 * being called from build_base_rel_tlists, but we may as well do
-			 * it always.
+			 * If we are creating PlaceHolderInfos, mark them with the
+			 * correct maybe-needed locations.  Otherwise, it's too late to
+			 * change that.
 			 */
-			phinfo->ph_may_need = bms_add_members(phinfo->ph_may_need,
-												  where_needed);
+			if (create_new_ph)
+				mark_placeholder_maybe_needed(root, phinfo, where_needed);
 		}
 		else
 			elog(ERROR, "unrecognized node type: %d", (int) nodeTag(node));
@@ -1035,7 +1042,7 @@ distribute_qual_to_rels(PlannerInfo *root, Node *clause,
 										   PVC_RECURSE_AGGREGATES,
 										   PVC_INCLUDE_PLACEHOLDERS);
 
-		add_vars_to_targetlist(root, vars, relids);
+		add_vars_to_targetlist(root, vars, relids, false);
 		list_free(vars);
 	}
 
diff --git a/src/backend/optimizer/util/placeholder.c b/src/backend/optimizer/util/placeholder.c
index 19862f39be..8b65245b51 100644
--- a/src/backend/optimizer/util/placeholder.c
+++ b/src/backend/optimizer/util/placeholder.c
@@ -24,7 +24,7 @@
 
 /* Local functions */
 static Relids find_placeholders_recurse(PlannerInfo *root, Node *jtnode);
-static void find_placeholders_in_qual(PlannerInfo *root, Node *qual,
+static void mark_placeholders_in_expr(PlannerInfo *root, Node *expr,
 						  Relids relids);
 
 
@@ -50,7 +50,10 @@ make_placeholder_expr(PlannerInfo *root, Expr *expr, Relids phrels)
 
 /*
  * find_placeholder_info
- *		Fetch the PlaceHolderInfo for the given PHV; create it if not found
+ *		Fetch the PlaceHolderInfo for the given PHV
+ *
+ * If the PlaceHolderInfo doesn't exist yet, create it if create_new_ph is
+ * true, else throw an error.
  *
  * This is separate from make_placeholder_expr because subquery pullup has
  * to make PlaceHolderVars for expressions that might not be used at all in
@@ -58,10 +61,13 @@ make_placeholder_expr(PlannerInfo *root, Expr *expr, Relids phrels)
  * We build PlaceHolderInfos only for PHVs that are still present in the
  * simplified query passed to query_planner().
  *
- * Note: this should only be called after query_planner() has started.
+ * Note: this should only be called after query_planner() has started.  Also,
+ * create_new_ph must not be TRUE after deconstruct_jointree begins, because
+ * make_outerjoininfo assumes that we already know about all placeholders.
  */
 PlaceHolderInfo *
-find_placeholder_info(PlannerInfo *root, PlaceHolderVar *phv)
+find_placeholder_info(PlannerInfo *root, PlaceHolderVar *phv,
+					  bool create_new_ph)
 {
 	PlaceHolderInfo *phinfo;
 	ListCell   *lc;
@@ -77,6 +83,9 @@ find_placeholder_info(PlannerInfo *root, PlaceHolderVar *phv)
 	}
 
 	/* Not found, so create it */
+	if (!create_new_ph)
+		elog(ERROR, "too late to create a new PlaceHolderInfo");
+
 	phinfo = makeNode(PlaceHolderInfo);
 
 	phinfo->phid = phv->phid;
@@ -157,7 +166,7 @@ find_placeholders_recurse(PlannerInfo *root, Node *jtnode)
 		/*
 		 * Now process the top-level quals.
 		 */
-		find_placeholders_in_qual(root, f->quals, jtrelids);
+		mark_placeholders_in_expr(root, f->quals, jtrelids);
 	}
 	else if (IsA(jtnode, JoinExpr))
 	{
@@ -173,7 +182,7 @@ find_placeholders_recurse(PlannerInfo *root, Node *jtnode)
 		jtrelids = bms_join(leftids, rightids);
 
 		/* Process the qual clauses */
-		find_placeholders_in_qual(root, j->quals, jtrelids);
+		mark_placeholders_in_expr(root, j->quals, jtrelids);
 	}
 	else
 	{
@@ -185,14 +194,15 @@ find_placeholders_recurse(PlannerInfo *root, Node *jtnode)
 }
 
 /*
- * find_placeholders_in_qual
- *		Process a qual clause for find_placeholders_in_jointree.
+ * mark_placeholders_in_expr
+ *		Find all PlaceHolderVars in the given expression, and mark them
+ *		as possibly needed at the specified join level.
  *
  * relids is the syntactic join level to mark as the "maybe needed" level
- * for each PlaceHolderVar found in the qual clause.
+ * for each PlaceHolderVar found in the expression.
  */
 static void
-find_placeholders_in_qual(PlannerInfo *root, Node *qual, Relids relids)
+mark_placeholders_in_expr(PlannerInfo *root, Node *expr, Relids relids)
 {
 	List	   *vars;
 	ListCell   *vl;
@@ -201,7 +211,7 @@ find_placeholders_in_qual(PlannerInfo *root, Node *qual, Relids relids)
 	 * pull_var_clause does more than we need here, but it'll do and it's
 	 * convenient to use.
 	 */
-	vars = pull_var_clause(qual,
+	vars = pull_var_clause(expr,
 						   PVC_RECURSE_AGGREGATES,
 						   PVC_INCLUDE_PLACEHOLDERS);
 	foreach(vl, vars)
@@ -214,26 +224,48 @@ find_placeholders_in_qual(PlannerInfo *root, Node *qual, Relids relids)
 			continue;
 
 		/* Create a PlaceHolderInfo entry if there's not one already */
-		phinfo = find_placeholder_info(root, phv);
-
-		/* Mark the PHV as possibly needed at the qual's syntactic level */
-		phinfo->ph_may_need = bms_add_members(phinfo->ph_may_need, relids);
+		phinfo = find_placeholder_info(root, phv, true);
 
-		/*
-		 * This is a bit tricky: the PHV's contained expression may contain
-		 * other, lower-level PHVs.  We need to get those into the
-		 * PlaceHolderInfo list, but they aren't going to be needed where the
-		 * outer PHV is referenced.  Rather, they'll be needed where the outer
-		 * PHV is evaluated.  We can estimate that (conservatively) as the
-		 * syntactic location of the PHV's expression.  Recurse to take care
-		 * of any such PHVs.
-		 */
-		find_placeholders_in_qual(root, (Node *) phv->phexpr, phv->phrels);
+		/* Mark it, and recursively process any contained placeholders */
+		mark_placeholder_maybe_needed(root, phinfo, relids);
 	}
 	list_free(vars);
 }
 
 /*
+ * mark_placeholder_maybe_needed
+ *		Mark a placeholder as possibly needed at the specified join level.
+ *
+ * relids is the syntactic join level to mark as the "maybe needed" level
+ * for the placeholder.
+ *
+ * This is called during an initial scan of the query's targetlist and quals
+ * before we begin deconstruct_jointree.  Once we begin deconstruct_jointree,
+ * all active placeholders must be present in root->placeholder_list with
+ * their correct ph_may_need values, because make_outerjoininfo and
+ * update_placeholder_eval_levels require this info to be available while
+ * we crawl up the join tree.
+ */
+void
+mark_placeholder_maybe_needed(PlannerInfo *root, PlaceHolderInfo *phinfo,
+							  Relids relids)
+{
+	/* Mark the PHV as possibly needed at the given syntactic level */
+	phinfo->ph_may_need = bms_add_members(phinfo->ph_may_need, relids);
+
+	/*
+	 * This is a bit tricky: the PHV's contained expression may contain other,
+	 * lower-level PHVs.  We need to get those into the PlaceHolderInfo list,
+	 * but they aren't going to be needed where the outer PHV is referenced.
+	 * Rather, they'll be needed where the outer PHV is evaluated.  We can
+	 * estimate that (conservatively) as the syntactic location of the PHV's
+	 * expression.  Recurse to take care of any such PHVs.
+	 */
+	mark_placeholders_in_expr(root, (Node *) phinfo->ph_var->phexpr,
+							  phinfo->ph_var->phrels);
+}
+
+/*
  * update_placeholder_eval_levels
  *		Adjust the target evaluation levels for placeholders
  *
@@ -353,7 +385,7 @@ fix_placeholder_input_needed_levels(PlannerInfo *root)
 											   PVC_RECURSE_AGGREGATES,
 											   PVC_INCLUDE_PLACEHOLDERS);
 
-			add_vars_to_targetlist(root, vars, eval_at);
+			add_vars_to_targetlist(root, vars, eval_at, false);
 			list_free(vars);
 		}
 	}
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 412bc96465..0696ae0182 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -2331,8 +2331,7 @@ reaper(SIGNAL_ARGS)
 			if (max_wal_senders > 0)
 			{
 				ereport(LOG,
-						(errmsg("terminating walsender all processes to force cascaded"
-								"standby(s) to update timeline and reconnect")));
+						(errmsg("terminating all walsender processes to force cascaded standby(s) to update timeline and reconnect")));
 				SignalSomeChildren(SIGUSR2, BACKEND_TYPE_WALSND);
 			}
 
diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
index 84e031dd53..d6a925e435 100644
--- a/src/bin/psql/command.c
+++ b/src/bin/psql/command.c
@@ -378,7 +378,7 @@ exec_command(const char *cmd,
 				success = describeTablespaces(pattern, show_verbose);
 				break;
 			case 'c':
-				success = listConversions(pattern, show_system);
+				success = listConversions(pattern, show_verbose, show_system);
 				break;
 			case 'C':
 				success = listCasts(pattern, show_verbose);
@@ -390,7 +390,7 @@ exec_command(const char *cmd,
 					success = objectDescription(pattern, show_system);
 				break;
 			case 'D':
-				success = listDomains(pattern, show_system);
+				success = listDomains(pattern, show_verbose, show_system);
 				break;
 			case 'f':			/* function subsystem */
 				switch (cmd[2])
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a8d5ddc96c..f08f917501 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -2665,10 +2665,8 @@ listLanguages(const char *pattern, bool verbose, bool showSystem)
 						  gettext_noop("Owner"));
 
 	appendPQExpBuffer(&buf,
-					  "       l.lanpltrusted AS \"%s\",\n"
-					  "       d.description AS \"%s\"",
-					  gettext_noop("Trusted"),
-					  gettext_noop("Description"));
+					  "       l.lanpltrusted AS \"%s\"",
+					  gettext_noop("Trusted"));
 
 	if (verbose)
 	{
@@ -2686,10 +2684,12 @@ listLanguages(const char *pattern, bool verbose, bool showSystem)
 	}
 
 	appendPQExpBuffer(&buf,
+					  ",\n       d.description AS \"%s\""
 					  "\nFROM pg_catalog.pg_language l\n"
 					  "LEFT JOIN pg_catalog.pg_description d\n"
 					  "  ON d.classoid = l.tableoid AND d.objoid = l.oid\n"
-					  "  AND d.objsubid = 0\n");
+					  "  AND d.objsubid = 0\n",
+					  gettext_noop("Description"));
 
 	if (pattern)
 		processSQLNamePattern(pset.db, &buf, pattern, false, false,
@@ -2723,7 +2723,7 @@ listLanguages(const char *pattern, bool verbose, bool showSystem)
  * Describes domains.
  */
 bool
-listDomains(const char *pattern, bool showSystem)
+listDomains(const char *pattern, bool verbose, bool showSystem)
 {
 	PQExpBufferData buf;
 	PGresult   *res;
@@ -2746,17 +2746,30 @@ listDomains(const char *pattern, bool showSystem)
 	appendPQExpBuffer(&buf,
 	   "            CASE WHEN t.typnotnull THEN ' not null' ELSE '' END ||\n"
 					  "            CASE WHEN t.typdefault IS NOT NULL THEN ' default ' || t.typdefault ELSE '' END\n"
-					  "       ) as \"%s\",\n",
-					  gettext_noop("Modifier"));
-	appendPQExpBuffer(&buf,
+					  "       ) as \"%s\",\n"
 					  "       pg_catalog.array_to_string(ARRAY(\n"
 					  "         SELECT pg_catalog.pg_get_constraintdef(r.oid, true) FROM pg_catalog.pg_constraint r WHERE t.oid = r.contypid\n"
-					  "       ), ' ') as \"%s\"\n"
-					  "FROM pg_catalog.pg_type t\n"
-	   "     LEFT JOIN pg_catalog.pg_namespace n ON n.oid = t.typnamespace\n"
-					  "WHERE t.typtype = 'd'\n",
+					  "       ), ' ') as \"%s\"",
+					  gettext_noop("Modifier"),
 					  gettext_noop("Check"));
 
+	if (verbose)
+		appendPQExpBuffer(&buf,
+						  ",\n       d.description as \"%s\"",
+						  gettext_noop("Description"));
+
+	appendPQExpBuffer(&buf,
+					  "\nFROM pg_catalog.pg_type t\n"
+	   "     LEFT JOIN pg_catalog.pg_namespace n ON n.oid = t.typnamespace\n");
+
+	if (verbose)
+		appendPQExpBuffer(&buf,
+						  "     LEFT JOIN pg_catalog.pg_description d "
+						  "ON d.classoid = t.tableoid AND d.objoid = t.oid "
+						  "AND d.objsubid = 0\n");
+
+	appendPQExpBuffer(&buf, "WHERE t.typtype = 'd'\n");
+
 	if (!showSystem && !pattern)
 		appendPQExpBuffer(&buf, "      AND n.nspname <> 'pg_catalog'\n"
 						  "      AND n.nspname <> 'information_schema'\n");
@@ -2788,7 +2801,7 @@ listDomains(const char *pattern, bool showSystem)
  * Describes conversions.
  */
 bool
-listConversions(const char *pattern, bool showSystem)
+listConversions(const char *pattern, bool verbose, bool showSystem)
 {
 	PQExpBufferData buf;
 	PGresult   *res;
@@ -2803,9 +2816,7 @@ listConversions(const char *pattern, bool showSystem)
 	   "       pg_catalog.pg_encoding_to_char(c.conforencoding) AS \"%s\",\n"
 		"       pg_catalog.pg_encoding_to_char(c.contoencoding) AS \"%s\",\n"
 					  "       CASE WHEN c.condefault THEN '%s'\n"
-					  "       ELSE '%s' END AS \"%s\"\n"
-			   "FROM pg_catalog.pg_conversion c, pg_catalog.pg_namespace n\n"
-					  "WHERE n.oid = c.connamespace\n",
+					  "       ELSE '%s' END AS \"%s\"",
 					  gettext_noop("Schema"),
 					  gettext_noop("Name"),
 					  gettext_noop("Source"),
@@ -2813,9 +2824,28 @@ listConversions(const char *pattern, bool showSystem)
 					  gettext_noop("yes"), gettext_noop("no"),
 					  gettext_noop("Default?"));
 
+	if (verbose)
+		appendPQExpBuffer(&buf,
+						  ",\n       d.description AS \"%s\"",
+						  gettext_noop("Description"));
+
+	appendPQExpBuffer(&buf,
+					  "\nFROM pg_catalog.pg_conversion c\n"
+					  "     JOIN pg_catalog.pg_namespace n "
+					  "ON n.oid = c.connamespace\n");
+
+	if (verbose)
+		appendPQExpBuffer(&buf,
+						  "LEFT JOIN pg_catalog.pg_description d "
+						  "ON d.classoid = c.tableoid\n"
+						  "          AND d.objoid = c.oid "
+						  "AND d.objsubid = 0\n");
+
+	appendPQExpBuffer(&buf, "WHERE true\n");
+
 	if (!showSystem && !pattern)
-		appendPQExpBuffer(&buf, "      AND n.nspname <> 'pg_catalog'\n"
-						  "      AND n.nspname <> 'information_schema'\n");
+		appendPQExpBuffer(&buf, "  AND n.nspname <> 'pg_catalog'\n"
+						  "  AND n.nspname <> 'information_schema'\n");
 
 	processSQLNamePattern(pset.db, &buf, pattern, true, false,
 						  "n.nspname", "c.conname", NULL,
@@ -3650,16 +3680,16 @@ listForeignDataWrappers(const char *pattern, bool verbose)
 
 	initPQExpBuffer(&buf);
 	printfPQExpBuffer(&buf,
-					  "SELECT fdwname AS \"%s\",\n"
-					  "  pg_catalog.pg_get_userbyid(fdwowner) AS \"%s\",\n",
+					  "SELECT fdw.fdwname AS \"%s\",\n"
+					  "  pg_catalog.pg_get_userbyid(fdw.fdwowner) AS \"%s\",\n",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"));
 	if (pset.sversion >= 90100)
 		appendPQExpBuffer(&buf,
-						  "  fdwhandler::pg_catalog.regproc AS \"%s\",\n",
+						  "  fdw.fdwhandler::pg_catalog.regproc AS \"%s\",\n",
 						  gettext_noop("Handler"));
 	appendPQExpBuffer(&buf,
-					  "  fdwvalidator::pg_catalog.regproc AS \"%s\"",
+					  "  fdw.fdwvalidator::pg_catalog.regproc AS \"%s\"",
 					  gettext_noop("Validator"));
 
 	if (verbose)
@@ -3669,9 +3699,20 @@ listForeignDataWrappers(const char *pattern, bool verbose)
 		appendPQExpBuffer(&buf,
 						  ",\n  fdwoptions AS \"%s\"",
 						  gettext_noop("Options"));
+
+		if (pset.sversion >= 90100)
+			appendPQExpBuffer(&buf,
+							  ",\n  d.description AS \"%s\" ",
+							  gettext_noop("Description"));
 	}
 
-	appendPQExpBuffer(&buf, "\nFROM pg_catalog.pg_foreign_data_wrapper\n");
+	appendPQExpBuffer(&buf, "\nFROM pg_catalog.pg_foreign_data_wrapper fdw\n");
+
+	if (verbose && pset.sversion >= 90100)
+		appendPQExpBuffer(&buf,
+						  "LEFT JOIN pg_catalog.pg_description d\n"
+						  "       ON d.classoid = fdw.tableoid "
+						  "AND d.objoid = fdw.oid AND d.objsubid = 0\n");
 
 	processSQLNamePattern(pset.db, &buf, pattern, false, false,
 						  NULL, "fdwname", NULL, NULL);
@@ -3729,16 +3770,24 @@ listForeignServers(const char *pattern, bool verbose)
 						  ",\n"
 						  "  s.srvtype AS \"%s\",\n"
 						  "  s.srvversion AS \"%s\",\n"
-						  "  s.srvoptions AS \"%s\"",
+						  "  s.srvoptions AS \"%s\",\n"
+						  "  d.description AS \"%s\"",
 						  gettext_noop("Type"),
 						  gettext_noop("Version"),
-						  gettext_noop("Options"));
+						  gettext_noop("Options"),
+						  gettext_noop("Description"));
 	}
 
 	appendPQExpBuffer(&buf,
 					  "\nFROM pg_catalog.pg_foreign_server s\n"
 	   "     JOIN pg_catalog.pg_foreign_data_wrapper f ON f.oid=s.srvfdw\n");
 
+	if (verbose)
+		appendPQExpBuffer(&buf,
+						  "LEFT JOIN pg_description d\n       "
+						  "ON d.classoid = s.tableoid AND d.objoid = s.oid "
+						  "AND d.objsubid = 0\n");
+
 	processSQLNamePattern(pset.db, &buf, pattern, false, false,
 						  NULL, "s.srvname", NULL, NULL);
 
@@ -3842,18 +3891,26 @@ listForeignTables(const char *pattern, bool verbose)
 
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  ft.ftoptions AS \"%s\"",
-						  gettext_noop("Options"));
+						  ",\n  ft.ftoptions AS \"%s\",\n"
+						  "  d.description AS \"%s\"",
+						  gettext_noop("Options"),
+						  gettext_noop("Description"));
 
-	appendPQExpBuffer(&buf, "\nFROM pg_catalog.pg_foreign_table ft,");
-	appendPQExpBuffer(&buf, "\n pg_catalog.pg_class c,");
-	appendPQExpBuffer(&buf, "\n pg_catalog.pg_namespace n,");
-	appendPQExpBuffer(&buf, "\n pg_catalog.pg_foreign_server s\n");
-	appendPQExpBuffer(&buf, "\nWHERE c.oid = ft.ftrelid");
-	appendPQExpBuffer(&buf, "\nAND s.oid = ft.ftserver\n");
-	appendPQExpBuffer(&buf, "\nAND n.oid = c.relnamespace\n");
+	appendPQExpBuffer(&buf,
+					  "\nFROM pg_catalog.pg_foreign_table ft\n"
+					  "  INNER JOIN pg_catalog.pg_class c"
+					  " ON c.oid = ft.ftrelid\n"
+					  "  INNER JOIN pg_catalog.pg_namespace n"
+					  " ON n.oid = c.relnamespace\n"
+					  "  INNER JOIN pg_catalog.pg_foreign_server s"
+					  " ON s.oid = ft.ftserver\n");
+	if (verbose)
+		appendPQExpBuffer(&buf,
+						  "   LEFT JOIN pg_catalog.pg_description d\n"
+						  "          ON d.classoid = c.tableoid AND "
+						  "d.objoid = c.oid AND d.objsubid = 0\n");
 
-	processSQLNamePattern(pset.db, &buf, pattern, true, false,
+	processSQLNamePattern(pset.db, &buf, pattern, false, false,
 						  NULL, "n.nspname", "c.relname", NULL);
 
 	appendPQExpBuffer(&buf, "ORDER BY 1, 2;");
diff --git a/src/bin/psql/describe.h b/src/bin/psql/describe.h
index 7dc9a2c154..bf4c31265e 100644
--- a/src/bin/psql/describe.h
+++ b/src/bin/psql/describe.h
@@ -61,10 +61,10 @@ extern bool listAllDbs(bool verbose);
 extern bool listTables(const char *tabtypes, const char *pattern, bool verbose, bool showSystem);
 
 /* \dD */
-extern bool listDomains(const char *pattern, bool showSystem);
+extern bool listDomains(const char *pattern, bool verbose, bool showSystem);
 
 /* \dc */
-extern bool listConversions(const char *pattern, bool showSystem);
+extern bool listConversions(const char *pattern, bool verbose, bool showSystem);
 
 /* \dC */
 extern bool listCasts(const char *pattern, bool verbose);
diff --git a/src/bin/psql/help.c b/src/bin/psql/help.c
index d3b8c170fa..b99ba3acfb 100644
--- a/src/bin/psql/help.c
+++ b/src/bin/psql/help.c
@@ -195,11 +195,11 @@ slashUsage(unsigned short int pager)
 	fprintf(output, _("  \\d[S+]  NAME           describe table, view, sequence, or index\n"));
 	fprintf(output, _("  \\da[S]  [PATTERN]      list aggregates\n"));
 	fprintf(output, _("  \\db[+]  [PATTERN]      list tablespaces\n"));
-	fprintf(output, _("  \\dc[S]  [PATTERN]      list conversions\n"));
+	fprintf(output, _("  \\dc[S+] [PATTERN]      list conversions\n"));
 	fprintf(output, _("  \\dC[+]  [PATTERN]      list casts\n"));
 	fprintf(output, _("  \\dd[S]  [PATTERN]      show comments on objects\n"));
 	fprintf(output, _("  \\ddp    [PATTERN]      list default privileges\n"));
-	fprintf(output, _("  \\dD[S]  [PATTERN]      list domains\n"));
+	fprintf(output, _("  \\dD[S+] [PATTERN]      list domains\n"));
 	fprintf(output, _("  \\det[+] [PATTERN]      list foreign tables\n"));
 	fprintf(output, _("  \\des[+] [PATTERN]      list foreign servers\n"));
 	fprintf(output, _("  \\deu[+] [PATTERN]      list user mappings\n"));
diff --git a/src/include/access/reloptions.h b/src/include/access/reloptions.h
index c7709cc058..14f50345bb 100644
--- a/src/include/access/reloptions.h
+++ b/src/include/access/reloptions.h
@@ -108,7 +108,7 @@ typedef struct relopt_string
 	int			default_len;
 	bool		default_isnull;
 	validate_string_relopt validate_cb;
-	char		default_val[1]; /* variable length, zero-terminated */
+	char	   *default_val;
 } relopt_string;
 
 /* This is the table datatype for fillRelOptions */
diff --git a/src/include/optimizer/placeholder.h b/src/include/optimizer/placeholder.h
index cce9e1ef1b..f112419fd5 100644
--- a/src/include/optimizer/placeholder.h
+++ b/src/include/optimizer/placeholder.h
@@ -20,8 +20,10 @@
 extern PlaceHolderVar *make_placeholder_expr(PlannerInfo *root, Expr *expr,
 					  Relids phrels);
 extern PlaceHolderInfo *find_placeholder_info(PlannerInfo *root,
-					  PlaceHolderVar *phv);
+					  PlaceHolderVar *phv, bool create_new_ph);
 extern void find_placeholders_in_jointree(PlannerInfo *root);
+extern void mark_placeholder_maybe_needed(PlannerInfo *root,
+							  PlaceHolderInfo *phinfo, Relids relids);
 extern void update_placeholder_eval_levels(PlannerInfo *root,
 							   SpecialJoinInfo *new_sjinfo);
 extern void fix_placeholder_input_needed_levels(PlannerInfo *root);
diff --git a/src/include/optimizer/planmain.h b/src/include/optimizer/planmain.h
index 5261691af6..69ba6b6923 100644
--- a/src/include/optimizer/planmain.h
+++ b/src/include/optimizer/planmain.h
@@ -92,7 +92,7 @@ extern int	join_collapse_limit;
 extern void add_base_rels_to_query(PlannerInfo *root, Node *jtnode);
 extern void build_base_rel_tlists(PlannerInfo *root, List *final_tlist);
 extern void add_vars_to_targetlist(PlannerInfo *root, List *vars,
-					   Relids where_needed);
+					   Relids where_needed, bool create_new_ph);
 extern List *deconstruct_jointree(PlannerInfo *root);
 extern void distribute_restrictinfo_to_rels(PlannerInfo *root,
 								RestrictInfo *restrictinfo);
diff --git a/src/test/regress/expected/foreign_data.out b/src/test/regress/expected/foreign_data.out
index 45292b5fde..ef13f2729f 100644
--- a/src/test/regress/expected/foreign_data.out
+++ b/src/test/regress/expected/foreign_data.out
@@ -52,12 +52,12 @@ ERROR:  foreign-data wrapper "foo" already exists
 DROP FOREIGN DATA WRAPPER foo;
 CREATE FOREIGN DATA WRAPPER foo OPTIONS (testing '1');
 \dew+
-                                     List of foreign-data wrappers
-    Name    |       Owner       | Handler |        Validator         | Access privileges |   Options   
-------------+-------------------+---------+--------------------------+-------------------+-------------
- dummy      | foreign_data_user | -       | -                        |                   | 
- foo        | foreign_data_user | -       | -                        |                   | {testing=1}
- postgresql | foreign_data_user | -       | postgresql_fdw_validator |                   | 
+                                            List of foreign-data wrappers
+    Name    |       Owner       | Handler |        Validator         | Access privileges |   Options   | Description 
+------------+-------------------+---------+--------------------------+-------------------+-------------+-------------
+ dummy      | foreign_data_user | -       | -                        |                   |             | useless
+ foo        | foreign_data_user | -       | -                        |                   | {testing=1} | 
+ postgresql | foreign_data_user | -       | postgresql_fdw_validator |                   |             | 
 (3 rows)
 
 DROP FOREIGN DATA WRAPPER foo;
@@ -65,12 +65,12 @@ CREATE FOREIGN DATA WRAPPER foo OPTIONS (testing '1', testing '2');   -- ERROR
 ERROR:  option "testing" provided more than once
 CREATE FOREIGN DATA WRAPPER foo OPTIONS (testing '1', another '2');
 \dew+
-                                          List of foreign-data wrappers
-    Name    |       Owner       | Handler |        Validator         | Access privileges |        Options        
-------------+-------------------+---------+--------------------------+-------------------+-----------------------
- dummy      | foreign_data_user | -       | -                        |                   | 
- foo        | foreign_data_user | -       | -                        |                   | {testing=1,another=2}
- postgresql | foreign_data_user | -       | postgresql_fdw_validator |                   | 
+                                                 List of foreign-data wrappers
+    Name    |       Owner       | Handler |        Validator         | Access privileges |        Options        | Description 
+------------+-------------------+---------+--------------------------+-------------------+-----------------------+-------------
+ dummy      | foreign_data_user | -       | -                        |                   |                       | useless
+ foo        | foreign_data_user | -       | -                        |                   | {testing=1,another=2} | 
+ postgresql | foreign_data_user | -       | postgresql_fdw_validator |                   |                       | 
 (3 rows)
 
 DROP FOREIGN DATA WRAPPER foo;
@@ -81,12 +81,12 @@ HINT:  Must be superuser to create a foreign-data wrapper.
 RESET ROLE;
 CREATE FOREIGN DATA WRAPPER foo VALIDATOR postgresql_fdw_validator;
 \dew+
-                                   List of foreign-data wrappers
-    Name    |       Owner       | Handler |        Validator         | Access privileges | Options 
-------------+-------------------+---------+--------------------------+-------------------+---------
- dummy      | foreign_data_user | -       | -                        |                   | 
- foo        | foreign_data_user | -       | postgresql_fdw_validator |                   | 
- postgresql | foreign_data_user | -       | postgresql_fdw_validator |                   | 
+                                          List of foreign-data wrappers
+    Name    |       Owner       | Handler |        Validator         | Access privileges | Options | Description 
+------------+-------------------+---------+--------------------------+-------------------+---------+-------------
+ dummy      | foreign_data_user | -       | -                        |                   |         | useless
+ foo        | foreign_data_user | -       | postgresql_fdw_validator |                   |         | 
+ postgresql | foreign_data_user | -       | postgresql_fdw_validator |                   |         | 
 (3 rows)
 
 -- ALTER FOREIGN DATA WRAPPER
@@ -98,12 +98,12 @@ ALTER FOREIGN DATA WRAPPER foo VALIDATOR bar;               -- ERROR
 ERROR:  function bar(text[], oid) does not exist
 ALTER FOREIGN DATA WRAPPER foo NO VALIDATOR;
 \dew+
-                                   List of foreign-data wrappers
-    Name    |       Owner       | Handler |        Validator         | Access privileges | Options 
-------------+-------------------+---------+--------------------------+-------------------+---------
- dummy      | foreign_data_user | -       | -                        |                   | 
- foo        | foreign_data_user | -       | -                        |                   | 
- postgresql | foreign_data_user | -       | postgresql_fdw_validator |                   | 
+                                          List of foreign-data wrappers
+    Name    |       Owner       | Handler |        Validator         | Access privileges | Options | Description 
+------------+-------------------+---------+--------------------------+-------------------+---------+-------------
+ dummy      | foreign_data_user | -       | -                        |                   |         | useless
+ foo        | foreign_data_user | -       | -                        |                   |         | 
+ postgresql | foreign_data_user | -       | postgresql_fdw_validator |                   |         | 
 (3 rows)
 
 ALTER FOREIGN DATA WRAPPER foo OPTIONS (a '1', b '2');
@@ -113,34 +113,34 @@ ALTER FOREIGN DATA WRAPPER foo OPTIONS (DROP c);            -- ERROR
 ERROR:  option "c" not found
 ALTER FOREIGN DATA WRAPPER foo OPTIONS (ADD x '1', DROP x);
 \dew+
-                                    List of foreign-data wrappers
-    Name    |       Owner       | Handler |        Validator         | Access privileges |  Options  
-------------+-------------------+---------+--------------------------+-------------------+-----------
- dummy      | foreign_data_user | -       | -                        |                   | 
- foo        | foreign_data_user | -       | -                        |                   | {a=1,b=2}
- postgresql | foreign_data_user | -       | postgresql_fdw_validator |                   | 
+                                           List of foreign-data wrappers
+    Name    |       Owner       | Handler |        Validator         | Access privileges |  Options  | Description 
+------------+-------------------+---------+--------------------------+-------------------+-----------+-------------
+ dummy      | foreign_data_user | -       | -                        |                   |           | useless
+ foo        | foreign_data_user | -       | -                        |                   | {a=1,b=2} | 
+ postgresql | foreign_data_user | -       | postgresql_fdw_validator |                   |           | 
 (3 rows)
 
 ALTER FOREIGN DATA WRAPPER foo OPTIONS (DROP a, SET b '3', ADD c '4');
 \dew+
-                                    List of foreign-data wrappers
-    Name    |       Owner       | Handler |        Validator         | Access privileges |  Options  
-------------+-------------------+---------+--------------------------+-------------------+-----------
- dummy      | foreign_data_user | -       | -                        |                   | 
- foo        | foreign_data_user | -       | -                        |                   | {b=3,c=4}
- postgresql | foreign_data_user | -       | postgresql_fdw_validator |                   | 
+                                           List of foreign-data wrappers
+    Name    |       Owner       | Handler |        Validator         | Access privileges |  Options  | Description 
+------------+-------------------+---------+--------------------------+-------------------+-----------+-------------
+ dummy      | foreign_data_user | -       | -                        |                   |           | useless
+ foo        | foreign_data_user | -       | -                        |                   | {b=3,c=4} | 
+ postgresql | foreign_data_user | -       | postgresql_fdw_validator |                   |           | 
 (3 rows)
 
 ALTER FOREIGN DATA WRAPPER foo OPTIONS (a '2');
 ALTER FOREIGN DATA WRAPPER foo OPTIONS (b '4');             -- ERROR
 ERROR:  option "b" provided more than once
 \dew+
-                                      List of foreign-data wrappers
-    Name    |       Owner       | Handler |        Validator         | Access privileges |    Options    
-------------+-------------------+---------+--------------------------+-------------------+---------------
- dummy      | foreign_data_user | -       | -                        |                   | 
- foo        | foreign_data_user | -       | -                        |                   | {b=3,c=4,a=2}
- postgresql | foreign_data_user | -       | postgresql_fdw_validator |                   | 
+                                             List of foreign-data wrappers
+    Name    |       Owner       | Handler |        Validator         | Access privileges |    Options    | Description 
+------------+-------------------+---------+--------------------------+-------------------+---------------+-------------
+ dummy      | foreign_data_user | -       | -                        |                   |               | useless
+ foo        | foreign_data_user | -       | -                        |                   | {b=3,c=4,a=2} | 
+ postgresql | foreign_data_user | -       | postgresql_fdw_validator |                   |               | 
 (3 rows)
 
 SET ROLE regress_test_role;
@@ -150,12 +150,12 @@ HINT:  Must be superuser to alter a foreign-data wrapper.
 SET ROLE regress_test_role_super;
 ALTER FOREIGN DATA WRAPPER foo OPTIONS (ADD d '5');
 \dew+
-                                        List of foreign-data wrappers
-    Name    |       Owner       | Handler |        Validator         | Access privileges |      Options      
-------------+-------------------+---------+--------------------------+-------------------+-------------------
- dummy      | foreign_data_user | -       | -                        |                   | 
- foo        | foreign_data_user | -       | -                        |                   | {b=3,c=4,a=2,d=5}
- postgresql | foreign_data_user | -       | postgresql_fdw_validator |                   | 
+                                               List of foreign-data wrappers
+    Name    |       Owner       | Handler |        Validator         | Access privileges |      Options      | Description 
+------------+-------------------+---------+--------------------------+-------------------+-------------------+-------------
+ dummy      | foreign_data_user | -       | -                        |                   |                   | useless
+ foo        | foreign_data_user | -       | -                        |                   | {b=3,c=4,a=2,d=5} | 
+ postgresql | foreign_data_user | -       | postgresql_fdw_validator |                   |                   | 
 (3 rows)
 
 ALTER FOREIGN DATA WRAPPER foo OWNER TO regress_test_role;  -- ERROR
@@ -169,12 +169,12 @@ ERROR:  permission denied to alter foreign-data wrapper "foo"
 HINT:  Must be superuser to alter a foreign-data wrapper.
 RESET ROLE;
 \dew+
-                                           List of foreign-data wrappers
-    Name    |          Owner          | Handler |        Validator         | Access privileges |      Options      
-------------+-------------------------+---------+--------------------------+-------------------+-------------------
- dummy      | foreign_data_user       | -       | -                        |                   | 
- foo        | regress_test_role_super | -       | -                        |                   | {b=3,c=4,a=2,d=5}
- postgresql | foreign_data_user       | -       | postgresql_fdw_validator |                   | 
+                                                  List of foreign-data wrappers
+    Name    |          Owner          | Handler |        Validator         | Access privileges |      Options      | Description 
+------------+-------------------------+---------+--------------------------+-------------------+-------------------+-------------
+ dummy      | foreign_data_user       | -       | -                        |                   |                   | useless
+ foo        | regress_test_role_super | -       | -                        |                   | {b=3,c=4,a=2,d=5} | 
+ postgresql | foreign_data_user       | -       | postgresql_fdw_validator |                   |                   | 
 (3 rows)
 
 -- DROP FOREIGN DATA WRAPPER
@@ -183,12 +183,12 @@ ERROR:  foreign-data wrapper "nonexistent" does not exist
 DROP FOREIGN DATA WRAPPER IF EXISTS nonexistent;
 NOTICE:  foreign-data wrapper "nonexistent" does not exist, skipping
 \dew+
-                                           List of foreign-data wrappers
-    Name    |          Owner          | Handler |        Validator         | Access privileges |      Options      
-------------+-------------------------+---------+--------------------------+-------------------+-------------------
- dummy      | foreign_data_user       | -       | -                        |                   | 
- foo        | regress_test_role_super | -       | -                        |                   | {b=3,c=4,a=2,d=5}
- postgresql | foreign_data_user       | -       | postgresql_fdw_validator |                   | 
+                                                  List of foreign-data wrappers
+    Name    |          Owner          | Handler |        Validator         | Access privileges |      Options      | Description 
+------------+-------------------------+---------+--------------------------+-------------------+-------------------+-------------
+ dummy      | foreign_data_user       | -       | -                        |                   |                   | useless
+ foo        | regress_test_role_super | -       | -                        |                   | {b=3,c=4,a=2,d=5} | 
+ postgresql | foreign_data_user       | -       | postgresql_fdw_validator |                   |                   | 
 (3 rows)
 
 DROP ROLE regress_test_role_super;                          -- ERROR
@@ -203,11 +203,11 @@ ALTER ROLE regress_test_role_super SUPERUSER;
 DROP FOREIGN DATA WRAPPER foo;
 DROP ROLE regress_test_role_super;
 \dew+
-                                   List of foreign-data wrappers
-    Name    |       Owner       | Handler |        Validator         | Access privileges | Options 
-------------+-------------------+---------+--------------------------+-------------------+---------
- dummy      | foreign_data_user | -       | -                        |                   | 
- postgresql | foreign_data_user | -       | postgresql_fdw_validator |                   | 
+                                          List of foreign-data wrappers
+    Name    |       Owner       | Handler |        Validator         | Access privileges | Options | Description 
+------------+-------------------+---------+--------------------------+-------------------+---------+-------------
+ dummy      | foreign_data_user | -       | -                        |                   |         | useless
+ postgresql | foreign_data_user | -       | postgresql_fdw_validator |                   |         | 
 (2 rows)
 
 CREATE FOREIGN DATA WRAPPER foo;
@@ -215,19 +215,19 @@ CREATE SERVER s1 FOREIGN DATA WRAPPER foo;
 COMMENT ON SERVER s1 IS 'foreign server';
 CREATE USER MAPPING FOR current_user SERVER s1;
 \dew+
-                                   List of foreign-data wrappers
-    Name    |       Owner       | Handler |        Validator         | Access privileges | Options 
-------------+-------------------+---------+--------------------------+-------------------+---------
- dummy      | foreign_data_user | -       | -                        |                   | 
- foo        | foreign_data_user | -       | -                        |                   | 
- postgresql | foreign_data_user | -       | postgresql_fdw_validator |                   | 
+                                          List of foreign-data wrappers
+    Name    |       Owner       | Handler |        Validator         | Access privileges | Options | Description 
+------------+-------------------+---------+--------------------------+-------------------+---------+-------------
+ dummy      | foreign_data_user | -       | -                        |                   |         | useless
+ foo        | foreign_data_user | -       | -                        |                   |         | 
+ postgresql | foreign_data_user | -       | postgresql_fdw_validator |                   |         | 
 (3 rows)
 
 \des+
-                                    List of foreign servers
- Name |       Owner       | Foreign-data wrapper | Access privileges | Type | Version | Options 
-------+-------------------+----------------------+-------------------+------+---------+---------
- s1   | foreign_data_user | foo                  |                   |      |         | 
+                                             List of foreign servers
+ Name |       Owner       | Foreign-data wrapper | Access privileges | Type | Version | Options |  Description   
+------+-------------------+----------------------+-------------------+------+---------+---------+----------------
+ s1   | foreign_data_user | foo                  |                   |      |         |         | foreign server
 (1 row)
 
 \deu+
@@ -252,17 +252,17 @@ NOTICE:  drop cascades to 2 other objects
 DETAIL:  drop cascades to server s1
 drop cascades to user mapping for foreign_data_user
 \dew+
-                                   List of foreign-data wrappers
-    Name    |       Owner       | Handler |        Validator         | Access privileges | Options 
-------------+-------------------+---------+--------------------------+-------------------+---------
- dummy      | foreign_data_user | -       | -                        |                   | 
- postgresql | foreign_data_user | -       | postgresql_fdw_validator |                   | 
+                                          List of foreign-data wrappers
+    Name    |       Owner       | Handler |        Validator         | Access privileges | Options | Description 
+------------+-------------------+---------+--------------------------+-------------------+---------+-------------
+ dummy      | foreign_data_user | -       | -                        |                   |         | useless
+ postgresql | foreign_data_user | -       | postgresql_fdw_validator |                   |         | 
 (2 rows)
 
 \des+
-                              List of foreign servers
- Name | Owner | Foreign-data wrapper | Access privileges | Type | Version | Options 
-------+-------+----------------------+-------------------+------+---------+---------
+                                     List of foreign servers
+ Name | Owner | Foreign-data wrapper | Access privileges | Type | Version | Options | Description 
+------+-------+----------------------+-------------------+------+---------+---------+-------------
 (0 rows)
 
 \deu+
@@ -289,17 +289,17 @@ ERROR:  invalid option "foo"
 HINT:  Valid options in this context are: authtype, service, connect_timeout, dbname, host, hostaddr, port, tty, options, requiressl, sslmode, gsslib
 CREATE SERVER s8 FOREIGN DATA WRAPPER postgresql OPTIONS (host 'localhost', dbname 's8db');
 \des+
-                                                List of foreign servers
- Name |       Owner       | Foreign-data wrapper | Access privileges |  Type  | Version |           Options            
-------+-------------------+----------------------+-------------------+--------+---------+------------------------------
- s1   | foreign_data_user | foo                  |                   |        |         | 
- s2   | foreign_data_user | foo                  |                   |        |         | {host=a,dbname=b}
- s3   | foreign_data_user | foo                  |                   | oracle |         | 
- s4   | foreign_data_user | foo                  |                   | oracle |         | {host=a,dbname=b}
- s5   | foreign_data_user | foo                  |                   |        | 15.0    | 
- s6   | foreign_data_user | foo                  |                   |        | 16.0    | {host=a,dbname=b}
- s7   | foreign_data_user | foo                  |                   | oracle | 17.0    | {host=a,dbname=b}
- s8   | foreign_data_user | postgresql           |                   |        |         | {host=localhost,dbname=s8db}
+                                                       List of foreign servers
+ Name |       Owner       | Foreign-data wrapper | Access privileges |  Type  | Version |           Options            | Description 
+------+-------------------+----------------------+-------------------+--------+---------+------------------------------+-------------
+ s1   | foreign_data_user | foo                  |                   |        |         |                              | 
+ s2   | foreign_data_user | foo                  |                   |        |         | {host=a,dbname=b}            | 
+ s3   | foreign_data_user | foo                  |                   | oracle |         |                              | 
+ s4   | foreign_data_user | foo                  |                   | oracle |         | {host=a,dbname=b}            | 
+ s5   | foreign_data_user | foo                  |                   |        | 15.0    |                              | 
+ s6   | foreign_data_user | foo                  |                   |        | 16.0    | {host=a,dbname=b}            | 
+ s7   | foreign_data_user | foo                  |                   | oracle | 17.0    | {host=a,dbname=b}            | 
+ s8   | foreign_data_user | postgresql           |                   |        |         | {host=localhost,dbname=s8db} | 
 (8 rows)
 
 SET ROLE regress_test_role;
@@ -311,18 +311,18 @@ SET ROLE regress_test_role;
 CREATE SERVER t1 FOREIGN DATA WRAPPER foo;
 RESET ROLE;
 \des+
-                                                List of foreign servers
- Name |       Owner       | Foreign-data wrapper | Access privileges |  Type  | Version |           Options            
-------+-------------------+----------------------+-------------------+--------+---------+------------------------------
- s1   | foreign_data_user | foo                  |                   |        |         | 
- s2   | foreign_data_user | foo                  |                   |        |         | {host=a,dbname=b}
- s3   | foreign_data_user | foo                  |                   | oracle |         | 
- s4   | foreign_data_user | foo                  |                   | oracle |         | {host=a,dbname=b}
- s5   | foreign_data_user | foo                  |                   |        | 15.0    | 
- s6   | foreign_data_user | foo                  |                   |        | 16.0    | {host=a,dbname=b}
- s7   | foreign_data_user | foo                  |                   | oracle | 17.0    | {host=a,dbname=b}
- s8   | foreign_data_user | postgresql           |                   |        |         | {host=localhost,dbname=s8db}
- t1   | regress_test_role | foo                  |                   |        |         | 
+                                                       List of foreign servers
+ Name |       Owner       | Foreign-data wrapper | Access privileges |  Type  | Version |           Options            | Description 
+------+-------------------+----------------------+-------------------+--------+---------+------------------------------+-------------
+ s1   | foreign_data_user | foo                  |                   |        |         |                              | 
+ s2   | foreign_data_user | foo                  |                   |        |         | {host=a,dbname=b}            | 
+ s3   | foreign_data_user | foo                  |                   | oracle |         |                              | 
+ s4   | foreign_data_user | foo                  |                   | oracle |         | {host=a,dbname=b}            | 
+ s5   | foreign_data_user | foo                  |                   |        | 15.0    |                              | 
+ s6   | foreign_data_user | foo                  |                   |        | 16.0    | {host=a,dbname=b}            | 
+ s7   | foreign_data_user | foo                  |                   | oracle | 17.0    | {host=a,dbname=b}            | 
+ s8   | foreign_data_user | postgresql           |                   |        |         | {host=localhost,dbname=s8db} | 
+ t1   | regress_test_role | foo                  |                   |        |         |                              | 
 (9 rows)
 
 REVOKE USAGE ON FOREIGN DATA WRAPPER foo FROM regress_test_role;
@@ -335,19 +335,19 @@ GRANT regress_test_indirect TO regress_test_role;
 SET ROLE regress_test_role;
 CREATE SERVER t2 FOREIGN DATA WRAPPER foo;
 \des+
-                                                List of foreign servers
- Name |       Owner       | Foreign-data wrapper | Access privileges |  Type  | Version |           Options            
-------+-------------------+----------------------+-------------------+--------+---------+------------------------------
- s1   | foreign_data_user | foo                  |                   |        |         | 
- s2   | foreign_data_user | foo                  |                   |        |         | {host=a,dbname=b}
- s3   | foreign_data_user | foo                  |                   | oracle |         | 
- s4   | foreign_data_user | foo                  |                   | oracle |         | {host=a,dbname=b}
- s5   | foreign_data_user | foo                  |                   |        | 15.0    | 
- s6   | foreign_data_user | foo                  |                   |        | 16.0    | {host=a,dbname=b}
- s7   | foreign_data_user | foo                  |                   | oracle | 17.0    | {host=a,dbname=b}
- s8   | foreign_data_user | postgresql           |                   |        |         | {host=localhost,dbname=s8db}
- t1   | regress_test_role | foo                  |                   |        |         | 
- t2   | regress_test_role | foo                  |                   |        |         | 
+                                                       List of foreign servers
+ Name |       Owner       | Foreign-data wrapper | Access privileges |  Type  | Version |           Options            | Description 
+------+-------------------+----------------------+-------------------+--------+---------+------------------------------+-------------
+ s1   | foreign_data_user | foo                  |                   |        |         |                              | 
+ s2   | foreign_data_user | foo                  |                   |        |         | {host=a,dbname=b}            | 
+ s3   | foreign_data_user | foo                  |                   | oracle |         |                              | 
+ s4   | foreign_data_user | foo                  |                   | oracle |         | {host=a,dbname=b}            | 
+ s5   | foreign_data_user | foo                  |                   |        | 15.0    |                              | 
+ s6   | foreign_data_user | foo                  |                   |        | 16.0    | {host=a,dbname=b}            | 
+ s7   | foreign_data_user | foo                  |                   | oracle | 17.0    | {host=a,dbname=b}            | 
+ s8   | foreign_data_user | postgresql           |                   |        |         | {host=localhost,dbname=s8db} | 
+ t1   | regress_test_role | foo                  |                   |        |         |                              | 
+ t2   | regress_test_role | foo                  |                   |        |         |                              | 
 (10 rows)
 
 RESET ROLE;
@@ -365,21 +365,21 @@ ALTER SERVER s3 OPTIONS (tnsname 'orcl', port '1521');
 GRANT USAGE ON FOREIGN SERVER s1 TO regress_test_role;
 GRANT USAGE ON FOREIGN SERVER s6 TO regress_test_role2 WITH GRANT OPTION;
 \des+
-                                                           List of foreign servers
- Name |       Owner       | Foreign-data wrapper |            Access privileges            |  Type  | Version |           Options            
-------+-------------------+----------------------+-----------------------------------------+--------+---------+------------------------------
- s1   | foreign_data_user | foo                  | foreign_data_user=U/foreign_data_user  +|        | 1.0     | {servername=s1}
-      |                   |                      | regress_test_role=U/foreign_data_user   |        |         | 
- s2   | foreign_data_user | foo                  |                                         |        | 1.1     | {host=a,dbname=b}
- s3   | foreign_data_user | foo                  |                                         | oracle |         | {tnsname=orcl,port=1521}
- s4   | foreign_data_user | foo                  |                                         | oracle |         | {host=a,dbname=b}
- s5   | foreign_data_user | foo                  |                                         |        | 15.0    | 
- s6   | foreign_data_user | foo                  | foreign_data_user=U/foreign_data_user  +|        | 16.0    | {host=a,dbname=b}
-      |                   |                      | regress_test_role2=U*/foreign_data_user |        |         | 
- s7   | foreign_data_user | foo                  |                                         | oracle | 17.0    | {host=a,dbname=b}
- s8   | foreign_data_user | postgresql           |                                         |        |         | {host=localhost,dbname=s8db}
- t1   | regress_test_role | foo                  |                                         |        |         | 
- t2   | regress_test_role | foo                  |                                         |        |         | 
+                                                                  List of foreign servers
+ Name |       Owner       | Foreign-data wrapper |            Access privileges            |  Type  | Version |           Options            | Description 
+------+-------------------+----------------------+-----------------------------------------+--------+---------+------------------------------+-------------
+ s1   | foreign_data_user | foo                  | foreign_data_user=U/foreign_data_user  +|        | 1.0     | {servername=s1}              | 
+      |                   |                      | regress_test_role=U/foreign_data_user   |        |         |                              | 
+ s2   | foreign_data_user | foo                  |                                         |        | 1.1     | {host=a,dbname=b}            | 
+ s3   | foreign_data_user | foo                  |                                         | oracle |         | {tnsname=orcl,port=1521}     | 
+ s4   | foreign_data_user | foo                  |                                         | oracle |         | {host=a,dbname=b}            | 
+ s5   | foreign_data_user | foo                  |                                         |        | 15.0    |                              | 
+ s6   | foreign_data_user | foo                  | foreign_data_user=U/foreign_data_user  +|        | 16.0    | {host=a,dbname=b}            | 
+      |                   |                      | regress_test_role2=U*/foreign_data_user |        |         |                              | 
+ s7   | foreign_data_user | foo                  |                                         | oracle | 17.0    | {host=a,dbname=b}            | 
+ s8   | foreign_data_user | postgresql           |                                         |        |         | {host=localhost,dbname=s8db} | 
+ t1   | regress_test_role | foo                  |                                         |        |         |                              | 
+ t2   | regress_test_role | foo                  |                                         |        |         |                              | 
 (10 rows)
 
 SET ROLE regress_test_role;
@@ -416,21 +416,21 @@ ERROR:  role "regress_test_indirect" cannot be dropped because some objects depe
 DETAIL:  owner of server s1
 privileges for foreign-data wrapper foo
 \des+
-                                                              List of foreign servers
- Name |         Owner         | Foreign-data wrapper |            Access privileges            |  Type  | Version |             Options             
-------+-----------------------+----------------------+-----------------------------------------+--------+---------+---------------------------------
- s1   | regress_test_indirect | foo                  | foreign_data_user=U/foreign_data_user  +|        | 1.1     | {servername=s1}
-      |                       |                      | regress_test_role=U/foreign_data_user   |        |         | 
- s2   | foreign_data_user     | foo                  |                                         |        | 1.1     | {host=a,dbname=b}
- s3   | foreign_data_user     | foo                  |                                         | oracle |         | {tnsname=orcl,port=1521}
- s4   | foreign_data_user     | foo                  |                                         | oracle |         | {host=a,dbname=b}
- s5   | foreign_data_user     | foo                  |                                         |        | 15.0    | 
- s6   | foreign_data_user     | foo                  | foreign_data_user=U/foreign_data_user  +|        | 16.0    | {host=a,dbname=b}
-      |                       |                      | regress_test_role2=U*/foreign_data_user |        |         | 
- s7   | foreign_data_user     | foo                  |                                         | oracle | 17.0    | {host=a,dbname=b}
- s8   | foreign_data_user     | postgresql           |                                         |        |         | {dbname=db1,connect_timeout=30}
- t1   | regress_test_role     | foo                  |                                         |        |         | 
- t2   | regress_test_role     | foo                  |                                         |        |         | 
+                                                                     List of foreign servers
+ Name |         Owner         | Foreign-data wrapper |            Access privileges            |  Type  | Version |             Options             | Description 
+------+-----------------------+----------------------+-----------------------------------------+--------+---------+---------------------------------+-------------
+ s1   | regress_test_indirect | foo                  | foreign_data_user=U/foreign_data_user  +|        | 1.1     | {servername=s1}                 | 
+      |                       |                      | regress_test_role=U/foreign_data_user   |        |         |                                 | 
+ s2   | foreign_data_user     | foo                  |                                         |        | 1.1     | {host=a,dbname=b}               | 
+ s3   | foreign_data_user     | foo                  |                                         | oracle |         | {tnsname=orcl,port=1521}        | 
+ s4   | foreign_data_user     | foo                  |                                         | oracle |         | {host=a,dbname=b}               | 
+ s5   | foreign_data_user     | foo                  |                                         |        | 15.0    |                                 | 
+ s6   | foreign_data_user     | foo                  | foreign_data_user=U/foreign_data_user  +|        | 16.0    | {host=a,dbname=b}               | 
+      |                       |                      | regress_test_role2=U*/foreign_data_user |        |         |                                 | 
+ s7   | foreign_data_user     | foo                  |                                         | oracle | 17.0    | {host=a,dbname=b}               | 
+ s8   | foreign_data_user     | postgresql           |                                         |        |         | {dbname=db1,connect_timeout=30} | 
+ t1   | regress_test_role     | foo                  |                                         |        |         |                                 | 
+ t2   | regress_test_role     | foo                  |                                         |        |         |                                 | 
 (10 rows)
 
 -- DROP SERVER
@@ -663,10 +663,10 @@ Server: sc
 Has OIDs: no
 
 \det+
-                List of foreign tables
- Schema | Table | Server |          Options           
---------+-------+--------+----------------------------
- public | ft1   | sc     | {"delimiter=,","quote=\""}
+                       List of foreign tables
+ Schema | Table | Server |          Options           | Description 
+--------+-------+--------+----------------------------+-------------
+ public | ft1   | sc     | {"delimiter=,","quote=\""} | ft1
 (1 row)
 
 CREATE INDEX id_ft1_c2 ON ft1 (c2);                             -- ERROR
diff --git a/src/test/regress/expected/join.out b/src/test/regress/expected/join.out
index 178214b4b9..a54000b27b 100644
--- a/src/test/regress/expected/join.out
+++ b/src/test/regress/expected/join.out
@@ -2489,6 +2489,51 @@ order by c.name;
 
 rollback;
 --
+-- test incorrect handling of placeholders that only appear in targetlists,
+-- per bug #6154
+--
+SELECT * FROM
+( SELECT 1 as key1 ) sub1
+LEFT JOIN
+( SELECT sub3.key3, sub4.value2, COALESCE(sub4.value2, 66) as value3 FROM
+    ( SELECT 1 as key3 ) sub3
+    LEFT JOIN
+    ( SELECT sub5.key5, COALESCE(sub6.value1, 1) as value2 FROM
+        ( SELECT 1 as key5 ) sub5
+        LEFT JOIN
+        ( SELECT 2 as key6, 42 as value1 ) sub6
+        ON sub5.key5 = sub6.key6
+    ) sub4
+    ON sub4.key5 = sub3.key3
+) sub2
+ON sub1.key1 = sub2.key3;
+ key1 | key3 | value2 | value3 
+------+------+--------+--------
+    1 |    1 |      1 |      1
+(1 row)
+
+-- test the path using join aliases, too
+SELECT * FROM
+( SELECT 1 as key1 ) sub1
+LEFT JOIN
+( SELECT sub3.key3, value2, COALESCE(value2, 66) as value3 FROM
+    ( SELECT 1 as key3 ) sub3
+    LEFT JOIN
+    ( SELECT sub5.key5, COALESCE(sub6.value1, 1) as value2 FROM
+        ( SELECT 1 as key5 ) sub5
+        LEFT JOIN
+        ( SELECT 2 as key6, 42 as value1 ) sub6
+        ON sub5.key5 = sub6.key6
+    ) sub4
+    ON sub4.key5 = sub3.key3
+) sub2
+ON sub1.key1 = sub2.key3;
+ key1 | key3 | value2 | value3 
+------+------+--------+--------
+    1 |    1 |      1 |      1
+(1 row)
+
+--
 -- test the corner cases FULL JOIN ON TRUE and FULL JOIN ON FALSE
 --
 select * from int4_tbl a full join int4_tbl b on true;
diff --git a/src/test/regress/sql/join.sql b/src/test/regress/sql/join.sql
index 3012031fce..1be80b8aeb 100644
--- a/src/test/regress/sql/join.sql
+++ b/src/test/regress/sql/join.sql
@@ -603,6 +603,43 @@ order by c.name;
 rollback;
 
 --
+-- test incorrect handling of placeholders that only appear in targetlists,
+-- per bug #6154
+--
+SELECT * FROM
+( SELECT 1 as key1 ) sub1
+LEFT JOIN
+( SELECT sub3.key3, sub4.value2, COALESCE(sub4.value2, 66) as value3 FROM
+    ( SELECT 1 as key3 ) sub3
+    LEFT JOIN
+    ( SELECT sub5.key5, COALESCE(sub6.value1, 1) as value2 FROM
+        ( SELECT 1 as key5 ) sub5
+        LEFT JOIN
+        ( SELECT 2 as key6, 42 as value1 ) sub6
+        ON sub5.key5 = sub6.key6
+    ) sub4
+    ON sub4.key5 = sub3.key3
+) sub2
+ON sub1.key1 = sub2.key3;
+
+-- test the path using join aliases, too
+SELECT * FROM
+( SELECT 1 as key1 ) sub1
+LEFT JOIN
+( SELECT sub3.key3, value2, COALESCE(value2, 66) as value3 FROM
+    ( SELECT 1 as key3 ) sub3
+    LEFT JOIN
+    ( SELECT sub5.key5, COALESCE(sub6.value1, 1) as value2 FROM
+        ( SELECT 1 as key5 ) sub5
+        LEFT JOIN
+        ( SELECT 2 as key6, 42 as value1 ) sub6
+        ON sub5.key5 = sub6.key6
+    ) sub4
+    ON sub4.key5 = sub3.key3
+) sub2
+ON sub1.key1 = sub2.key3;
+
+--
 -- test the corner cases FULL JOIN ON TRUE and FULL JOIN ON FALSE
 --
 select * from int4_tbl a full join int4_tbl b on true;