Function postgresPlanForeignModify

contrib/postgres_fdw/postgres_fdw.c:1764–1896

* postgresPlanForeignModify * Plan an insert/update/delete operation on a foreign table */

 *		Plan an insert/update/delete operation on a foreign table
 */
static List *
postgresPlanForeignModify(PlannerInfo *root,
						  ModifyTable *plan,
						  Index resultRelation,
						  int subplan_index)
{
	CmdType		operation = plan->operation;
	RangeTblEntry *rte = planner_rt_fetch(resultRelation, root);
	Relation	rel;
	StringInfoData sql;
	List	   *targetAttrs = NIL;
	List	   *withCheckOptionList = NIL;
	List	   *returningList = NIL;
	List	   *retrieved_attrs = NIL;
	bool		doNothing = false;
	int			values_end_len = -1;

	initStringInfo(&sql);

	/*
	 * Core code already has some lock on each rel being planned, so we can
	 * use NoLock here.
	 */
	rel = table_open(rte->relid, NoLock);

	/*
	 * In an INSERT, we transmit all columns that are defined in the foreign
	 * table.  In an UPDATE, if there are BEFORE ROW UPDATE triggers on the
	 * foreign table, we transmit all columns like INSERT; else we transmit
	 * only columns that were explicitly targets of the UPDATE, so as to avoid
	 * unnecessary data transmission.  (We can't do that for INSERT since we
	 * would miss sending default values for columns not listed in the source
	 * statement, and for UPDATE if there are BEFORE ROW UPDATE triggers since
	 * those triggers might change values for non-target columns, in which
	 * case we would miss sending changed values for those columns.)
	 */
	if (operation == CMD_INSERT ||
		(operation == CMD_UPDATE &&
		 rel->trigdesc &&
		 rel->trigdesc->trig_update_before_row))
	{
		TupleDesc	tupdesc = RelationGetDescr(rel);
		int			attnum;

		for (attnum = 1; attnum <= tupdesc->natts; attnum++)
		{
			Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);

			if (!attr->attisdropped)
				targetAttrs = lappend_int(targetAttrs, attnum);
		}
	}
	else if (operation == CMD_UPDATE)
	{
		int			col;
		Bitmapset  *allUpdatedCols = bms_union(rte->updatedCols, rte->extraUpdatedCols);

		col = -1;