1 files changed, 218 insertions, 4 deletions

diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c
index 382e56888c..8a42c7176d 100644
--- a/src/backend/optimizer/plan/createplan.c
+++ b/src/backend/optimizer/plan/createplan.c
@@ -5414,7 +5414,7 @@ create_remoteinsert_plan(PlannerInfo *root, Plan *topplan)
 
 		buf = makeStringInfo();
 
-		/* Compose DELETE FROM target_table */
+		/* Compose INSERT FROM target_table */
 		nspid = get_rel_namespace(ttab->relid);
 		nspname = get_namespace_name(nspid);
 
@@ -5549,11 +5549,226 @@ create_remoteinsert_plan(PlannerInfo *root, Plan *topplan)
 /*
  * create_remoteupdate_plan()
  *
- * Dummy
+ * For every target relation, add a remote query node to carry out remote
+ * operations.
+ * WHERE and SET clauses are populated with the relation attributes.
+ * Target list is used for SET clause and completed with the expressions already given.
+ * SET clause is completed with new parameters whose values are resulting from the
+ * SELECT query generated by create_remotequery_plan.
  */
 Plan *
 create_remoteupdate_plan(PlannerInfo *root, Plan *topplan)
 {
+	ModifyTable *mt = (ModifyTable *)topplan;
+	ListCell	*l;
+
+	/* We expect to work only on ModifyTable node */
+	if (!IsA(topplan, ModifyTable))
+		elog(ERROR, "Unexpected node type: %d", topplan->type);
+
+	/*
+	 * For every result relation, build a remote plan to execute remote update.
+	 */
+	foreach(l, mt->resultRelations)
+	{
+		Index			resultRelationIndex = lfirst_int(l);
+		Query			*parse = root->parse;
+		RangeTblEntry   *ttab;
+		RelationLocInfo *rel_loc_info;
+		StringInfo		buf, buf2;
+		Oid			    nspid;		/* Relation namespace Oid */
+		char		   *nspname;	/* Relation namespace name */
+		Oid			   *att_types;	/* Types of query parameters */
+		int				natts, att;
+		List		   *tlist = NIL;			/* Target list of remote UPDATE */
+		bool			is_set_printed = false;	/* Control of SET generation */
+		bool			is_where_printed = false;	/* Control of WHERE generation */
+		RemoteQuery	   *fstep;		/* Plan step generated */
+
+		ttab = rt_fetch(resultRelationIndex, parse->rtable);
+
+		/* Bad relation ? */
+		if (ttab == NULL || ttab->rtekind != RTE_RELATION)
+			continue;
+
+		/* Get location info of the target table */
+		rel_loc_info = GetRelationLocInfo(ttab->relid);
+		if (rel_loc_info == NULL)
+			continue;
+
+		/* Get number of arrtibutes */
+		natts = get_relnatts(ttab->relid);
+
+		/*
+		 * PGXCTODO: Allow use of remote UPDATE in case all the columns are
+		 * updated at once. In this case, create_remotequery_plan refers to
+		 * remote tuples with only the ctid which is not used by this part of
+		 * planning. CTID needs to be coupled with the node name of where
+		 * the tuple is located to avoid inconsistency due to similar CTIDs
+		 * among PGXC remote nodes.
+		 * This has no impact on distributed table as distribution column
+		 * cannot be updated yet, so only replicated tables are impacted now.
+		 */
+		if (list_length(parse->targetList) == natts + 1)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("Postgres-XC does not support remote UPDATE on all columns"),
+					 errdetail("At least one column reference to a remote value is necessary")));
+
+		/* Create query buffers */
+		buf = makeStringInfo();		/* For SET clause */
+		buf2 = makeStringInfo();	/* For WHERE clause */
+
+		/* Compose UPDATE target_table */
+		nspid = get_rel_namespace(ttab->relid);
+		nspname = get_namespace_name(nspid);
+
+		/*
+		 * Do not qualify with namespace for TEMP tables. The schema name may
+		 * vary on each node
+		 */
+		if (IsTempTable(ttab->relid))
+			appendStringInfo(buf, "UPDATE %s SET",
+							 quote_identifier(ttab->relname));
+		else
+			appendStringInfo(buf, "UPDATE %s.%s SET ", quote_identifier(nspname),
+							 quote_identifier(ttab->relname));
+		fstep = make_remotequery(NIL, ttab, NIL, ttab->relid);
+		fstep->is_temp = IsTempTable(ttab->relid);
+
+		/* All the parameters are the tuple attributes */
+		att_types = (Oid *) palloc0 (sizeof (Oid) * natts);
+
+		/*
+		 * Populate the SET and WHERE clauses with parameters.
+		 * WHERE clause is completed by attributes located in the target list
+		 * as those parameters will be set with the result of the SELECT remote
+		 * query generated by create_remotequery_plan.
+		 * SET is completed with the attributes in remote query and their given
+		 * expressions.
+		 */
+		for (att = 1; att <= natts; att++)
+		{
+			HeapTuple tp;
+
+			tp = SearchSysCache(ATTNUM,
+			ObjectIdGetDatum(ttab->relid),
+								Int16GetDatum(att),
+								0, 0);
+			if (HeapTupleIsValid(tp))
+			{
+				Form_pg_attribute att_tup = (Form_pg_attribute) GETSTRUCT(tp);
+				ListCell *elt;
+				bool is_found = false;
+				TargetEntry *tle_saved;
+
+				/*
+				 * Attributes in the target list are inserted in the SET clause directly
+				 * because they are the values being changed, the attributes not in target
+				 * list are used to select correct elements on remote nodes and added in target list.
+				 */
+				foreach(elt, parse->targetList)
+				{
+					TargetEntry *tle = lfirst(elt);
+					tle_saved = tle;
+					if (strcmp(tle->resname, NameStr(att_tup->attname)) == 0)
+					{
+						is_found = true;
+						break;
+					}
+				}
+
+				/*
+				 * If attribute is found in target list, add it to SET clause and
+				 * create associated parameter. If it is not found, this attribute
+				 * is used in WHERE clause with a new parameter whose value is set
+				 * with the SELECT query created by create_remotequery_plan on top
+				 * of this plan.
+				 */
+				if (is_found)
+				{
+					TargetEntry *tle;
+
+					/* Add comma before all except first attributes */
+					if (!is_set_printed)
+						is_set_printed = true;
+					else
+						appendStringInfoString(buf, ", ");
+
+					att_types[att - 1] = att_tup->atttypid;
+					appendStringInfo(buf, "%s = $%d",
+									 quote_identifier(NameStr(att_tup->attname)),
+									 att);
+
+					/*
+					 * Add attribute to target list for remote query,
+					 * and use here the original target entry expression
+					 */
+					tle = makeTargetEntry(tle_saved->expr, att,
+										  NameStr(att_tup->attname), false);
+					tlist = lappend(tlist, tle);
+				}
+				else
+				{
+					TargetEntry *tle;
+					Var *expr;
+
+					/* Set the clause if necessary */
+					if (!is_where_printed)
+					{
+						is_where_printed = true;
+						appendStringInfoString(buf2, " WHERE ");
+					}
+					else
+						appendStringInfoString(buf2, "AND ");
+
+					/* Build parameter string */
+					att_types[att - 1] = att_tup->atttypid;
+					appendStringInfo(buf2, "%s = $%d ",
+									 quote_identifier(NameStr(att_tup->attname)),
+									 att);
+
+					/* Add parameter to the target list for remote query */
+					expr = makeVar(att, att, att_tup->atttypid,
+								   att_tup->atttypmod, InvalidOid, 0);
+					tle = makeTargetEntry((Expr *) expr, att,
+										  NameStr(att_tup->attname), false);
+					tlist = lappend(tlist, tle);
+				}
+				ReleaseSysCache(tp);
+			}
+			else
+				elog(ERROR, "cache lookup failed for attribute %d of relation %u",
+					 att, ttab->relid);
+		}
+
+		/* Finish building the query by gathering SET and WHERE clauses */
+		appendStringInfo(buf, "%s", buf2->data);
+
+		/* Finally build the final UPDATE step */
+		fstep = make_remotequery(tlist, ttab, NIL, ttab->relid);
+		fstep->is_temp = IsTempTable(ttab->relid);
+		fstep->sql_statement = pstrdup(buf->data);
+		fstep->combine_type = COMBINE_TYPE_NONE;
+
+		fstep->read_only = false;
+		fstep->exec_nodes = makeNode(ExecNodes);
+		fstep->exec_nodes = GetRelationNodes(rel_loc_info, 0, UNKNOWNOID, RELATION_ACCESS_UPDATE);
+		fstep->exec_nodes->baselocatortype = rel_loc_info->locatorType;
+		fstep->exec_nodes->tableusagetype = TABLE_USAGE_TYPE_USER;
+		fstep->exec_nodes->primarynodelist = NULL;
+		fstep->exec_nodes->nodeList = NULL;
+		fstep->exec_nodes->en_relid = ttab->relid;
+		fstep->exec_nodes->accesstype = RELATION_ACCESS_UPDATE;
+		SetRemoteStatementName((Plan *) fstep, NULL, natts, att_types, 0);
+		pfree(buf->data);
+		pfree(buf2->data);
+		pfree(buf);
+		pfree(buf2);
+
+		mt->remote_plans = lappend(mt->remote_plans, fstep);
+	}
+
 	return topplan;
 }
 
@@ -5587,7 +5802,6 @@ create_remotedelete_plan(PlannerInfo *root, Plan *topplan)
 	char		   *nspname;
 	Var 		   *ctid;
 
-
 	/* Get target table */
 	ttab = (RangeTblEntry *) list_nth(parse->rtable, parse->resultRelation - 1);
 	/* Bad relation ? */
@@ -5989,7 +6203,7 @@ create_remotegrouping_plan(PlannerInfo *root, Plan *local_plan)
 	remote_group->remotejoin			= false;
 	remote_group->inner_alias			= pstrdup(in_alias->data);
 	remote_group->inner_reduce_level	= remote_scan->reduce_level;
-	remote_group->inner_relids      	= in_relids;
+	remote_group->inner_relids			= in_relids;
 	remote_group->inner_statement		= pstrdup(remote_scan->sql_statement);
 	remote_group->exec_nodes			= remote_scan->exec_nodes;
 	/* Don't forget to increment the index for the next time around! */