SQL> desc user_tables
 名称                                      是否为空? 类型
 ----------------------------------------- -------- ----------------------------

 TABLE_NAME                                NOT NULL VARCHAR2(30)
 TABLESPACE_NAME                                    VARCHAR2(30)
 CLUSTER_NAME                                       VARCHAR2(30)
 IOT_NAME                                           VARCHAR2(30)
 STATUS                                             VARCHAR2(8)
 PCT_FREE                                           NUMBER
 PCT_USED                                           NUMBER
 INI_TRANS                                          NUMBER
 MAX_TRANS                                          NUMBER
 INITIAL_EXTENT                                     NUMBER
 NEXT_EXTENT                                        NUMBER
 MIN_EXTENTS                                        NUMBER
 MAX_EXTENTS                                        NUMBER
 PCT_INCREASE                                       NUMBER
 FREELISTS                                          NUMBER
 FREELIST_GROUPS                                    NUMBER
 LOGGING                                            VARCHAR2(3)
 BACKED_UP                                          VARCHAR2(1)
 NUM_ROWS                                           NUMBER
 BLOCKS                                             NUMBER
 EMPTY_BLOCKS                                       NUMBER
 AVG_SPACE                                          NUMBER
 CHAIN_CNT                                          NUMBER
 AVG_ROW_LEN                                        NUMBER
 AVG_SPACE_FREELIST_BLOCKS                          NUMBER
 NUM_FREELIST_BLOCKS                                NUMBER
 DEGREE                                             VARCHAR2(10)
 INSTANCES                                          VARCHAR2(10)
 CACHE                                              VARCHAR2(5)
 TABLE_LOCK                                         VARCHAR2(8)
 SAMPLE_SIZE                                        NUMBER
 LAST_ANALYZED                                      DATE
 PARTITIONED                                        VARCHAR2(3)
 IOT_TYPE                                           VARCHAR2(12)
 TEMPORARY                                          VARCHAR2(1)
 SECONDARY                                          VARCHAR2(1)
 NESTED                                             VARCHAR2(3)
 BUFFER_POOL                                        VARCHAR2(7)
 ROW_MOVEMENT                                       VARCHAR2(8)
 GLOBAL_STATS                                       VARCHAR2(3)
 USER_STATS                                         VARCHAR2(3)
 DURATION                                           VARCHAR2(15)
 SKIP_CORRUPT                                       VARCHAR2(8)
 MONITORING                                         VARCHAR2(3)
 CLUSTER_OWNER                                      VARCHAR2(30)
 DEPENDENCIES                                       VARCHAR2(8)
 COMPRESSION                                        VARCHAR2(8)
 COMPRESS_FOR                                       VARCHAR2(18)
 DROPPED                                            VARCHAR2(3)
 READ_ONLY                                          VARCHAR2(3)