Function DetachPartitionFinalize

src/backend/commands/tablecmds.c:22351–22552

* Second part of ALTER TABLE .. DETACH. * * This is separate so that it can be run independently when the second * transaction of the concurrent algorithm fails (crash or abort). */

 * transaction of the concurrent algorithm fails (crash or abort).
 */
static void
DetachPartitionFinalize(Relation rel, Relation partRel, bool concurrent,
						Oid defaultPartOid)
{
	Relation	classRel;
	List	   *fks;
	ListCell   *cell;
	List	   *indexes;
	Datum		new_val[Natts_pg_class];
	bool		new_null[Natts_pg_class],
				new_repl[Natts_pg_class];
	HeapTuple	tuple,
				newtuple;

	if (concurrent)
	{
		/*
		 * Update status of parent relative views.
		 * We must do this before RemoveInheritance.
		 * Detach a partition means delete data from parent.
		 */
		if (IS_QD_OR_SINGLENODE())
			SetRelativeMatviewAuxStatus(RelationGetRelid(rel),
										MV_DATA_STATUS_EXPIRED,
										MV_DATA_STATUS_TRANSFER_DIRECTION_UP);

		/*
		 * We can remove the pg_inherits row now. (In the non-concurrent case,
		 * this was already done).
		 */
		RemoveInheritance(partRel, rel, true);
	}

	/* Drop any triggers that were cloned on creation/attach. */
	DropClonedTriggersFromPartition(RelationGetRelid(partRel));

	/*
	 * Detach any foreign keys that are inherited.  This includes creating
	 * additional action triggers.
	 */
	fks = copyObject(RelationGetFKeyList(partRel));
	foreach(cell, fks)
	{
		ForeignKeyCacheInfo *fk = lfirst(cell);
		HeapTuple	contup;
		Form_pg_constraint conform;
		Constraint *fkconstraint;

		contup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(fk->conoid));
		if (!HeapTupleIsValid(contup))
			elog(ERROR, "cache lookup failed for constraint %u", fk->conoid);
		conform = (Form_pg_constraint) GETSTRUCT(contup);

		/* consider only the inherited foreign keys */
		if (conform->contype != CONSTRAINT_FOREIGN ||
			!OidIsValid(conform->conparentid))
		{
			ReleaseSysCache(contup);