Function ATExecGPPartCmds

src/backend/commands/tablecmds_gp.c:1111–1483

}

void
ATExecGPPartCmds(Relation origrel, AlterTableCmd *cmd)
{
	Relation rel = origrel;
	List *stmts = NIL;
	ListCell *l;

	while (cmd->subtype == AT_PartAlter)
	{
		GpAlterPartitionCmd *pc;
		GpAlterPartitionId  *pid;
		Oid                 partrelid;

		pc  = castNode(GpAlterPartitionCmd, cmd->def);
		pid = (GpAlterPartitionId *) pc->partid;
		cmd = (AlterTableCmd *) pc->arg;

		if (rel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
		{
			ereport(ERROR,
					(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
					 errmsg("table \"%s\" is not partitioned",
							RelationGetRelationName(rel))));
		}

		partrelid = GpFindTargetPartition(rel, pid, false);
		Assert(OidIsValid(partrelid));

		if (rel != origrel)
			table_close(rel, AccessShareLock);
		rel = table_open(partrelid, AccessShareLock);
	}

	/*
	 * Most ALTER PARTITION commands are to ADD/DROP subpartitions, and don't
	 * make sense unless the partition itself is a partitioned table. SET
	 * DISTRIBUTED BY and SET TABLESPACE are exceptions.
	 */
	if (rel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE &&
		cmd->subtype != AT_SetDistributedBy &&
		cmd->subtype != AT_SetTableSpace)
	{
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
				 errmsg("table \"%s\" is not partitioned",
						RelationGetRelationName(rel))));
	}

	switch (cmd->subtype)
	{
		case AT_PartTruncate:
		{
			GpAlterPartitionCmd *pc = castNode(GpAlterPartitionCmd, cmd->def);
			GpAlterPartitionId *pid = (GpAlterPartitionId *) pc->partid;
			TruncateStmt *truncstmt = (TruncateStmt *) pc->arg;
			Oid partrelid;
			RangeVar *rv;
			Relation partrel;