Function CreateStorageUserMapping

src/backend/commands/storagecmds.c:635–751

* Create Storage User Mapping */

 * Create Storage User Mapping
 */
ObjectAddress
CreateStorageUserMapping(CreateStorageUserMappingStmt *stmt)
{
	Relation 	rel;
	Datum 		useoptions;
	Datum 		values[Natts_gp_storage_user_mapping];
	bool 		nulls[Natts_gp_storage_user_mapping];
	HeapTuple 	tuple;
	Oid			useId;
	Oid 		umId;
	StorageServer *srv;
	ObjectAddress myself;
	RoleSpec	*role = (RoleSpec *) stmt->user;

	rel = table_open(StorageUserMappingRelationId, RowExclusiveLock);

	if (role->roletype == ROLESPEC_PUBLIC)
		useId = ACL_ID_PUBLIC;
	else
		useId = get_rolespec_oid(stmt->user, false);

	/* Check that the server exists. */
	srv = GetStorageServerByName(stmt->servername, false);

	storage_user_mapping_ddl_aclcheck(useId, srv->serverid, stmt->servername);

	/*
	 * Check that the user mapping is unique within server.
	 */
	umId = GetSysCacheOid2(STORAGEUSERMAPPINGUSERSERVER, Anum_gp_storage_user_mapping_oid,
						   ObjectIdGetDatum(useId),
						   ObjectIdGetDatum(srv->serverid));

	if (OidIsValid(umId))
	{
		if (stmt->if_not_exists)
		{
			ereport(NOTICE,
					(errcode(ERRCODE_DUPLICATE_OBJECT),
					 errmsg("storage user mapping for \"%s\" already exists for storage server \"%s\", skipping",
			 		 StorageMappingUserName(useId),
			 		 stmt->servername)));

			table_close(rel, RowExclusiveLock);
			return InvalidObjectAddress;
		}
		else
			ereport(ERROR,
					(errcode(ERRCODE_DUPLICATE_OBJECT),
					 errmsg("storage user mapping for \"%s\" already exists for storage server \"%s\"",
			 		 StorageMappingUserName(useId),
			 		 stmt->servername)));
	}

	/*
	 * Insert tuple into gp_storage_user_mapping.
	 */
	memset(values, 0, sizeof(values));