错误描述：

SQL> alter tablespace users resize 300m;
alter tablespace users resize 300m
*
ERROR at line 1:
ORA-32773: operation not supported for smallfile tablespace USERS

SQL> select file_id, tablespace_name from dba_data_files;

   FILE_ID TABLESPACE_NAME
---------- ------------------------------
         1 SYSTEM
         2 UNDOTBS1
         3 SYSAUX
         4 USERS

SQL> alter database datafile 4 resize 300m;

Database altered.

//--------Description from online documents------------------------------------------------------------------
ORA-32773: operation not supported for smallfile tablespace string
Cause: An attempt was made to perform. an operation which is supported only for bigfile tablespaces, e.g. resize tablespace.
Action: Use the appropriate clause of the ALTER DATABASE DATAFILE command instead.

SQL> alter tablespace users autoextend off;
alter tablespace users autoextend off
*
ERROR at line 1:
ORA-32773: operation not supported for smallfile tablespace USERS

SQL> alter database datafile 4 autoextend off;

Database altered.

小错误也记一下，全当积累了~~~