1.查看表空间

col tablespace_name format a10;
col file_name format a30;
col total_space format a10;

SELECT tablespace_name,  
file_name, 
round(bytes/(1024*1024*1024), 2)||' GB' total_space 
FROM dba_data_files 
ORDER BY tablespace_name;

2.查看用户

SQL> select USERNAME,ACCOUNT_STATUS from dba_users;

USERNAME                       ACCOUNT_STATUS
------------------------------ --------------------------------
EOS_WORKFLOW                   OPEN
EOS_UNIT_WK                    OPEN
EOSGW                          OPEN
EOS7                           OPEN
PORTAL                         OPEN
.....

3.查看数据库内存

SQL> show parameter sga;

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
lock_sga                             boolean     FALSE
pre_page_sga                         boolean     FALSE
sga_max_size                         big integer 233984M
sga_target                           big integer 233984M

4.查看数据库版本

SQL> select * from v$version;

BANNER
--------------------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
PL/SQL Release 11.2.0.4.0 - Production
CORE    11.2.0.4.0      Production
TNS for Linux: Version 11.2.0.4.0 - Production
NLSRTL Version 11.2.0.4.0 - Production

5.oracle归档情况

SQL> archive log list;
Database log mode              Archive Mode
Automatic archival             Enabled
Archive destination            +DATA/archivelog
Oldest online log sequence     4695
Next log sequence to archive   4696
Current log sequence           4696

6.查看redo log日志位置

SQL> col member format a30;
SQL> select group#,member from v$logfile;

    GROUP# MEMBER
---------- ------------------------------
         1 +DATA/newarpdb/redo01.log
         2 +DATA/newarpdb/redo02.log
         3 +DATA/newarpdb/redo03.log
         4 +DATA/newarpdb/redo04.log

7.查看数据库的控制文件

SQL> col name format a60;
SQL> select status,name from v$controlfile;

STATUS  NAME
------- ------------------------------------------------------------
        +DATA/newarpdb/control01.ctl
        +DATA/newarpdb/control02.ctl

8.查看RMAN的备份情况

COL STATUS FORMAT a9
COL hrs    FORMAT 999.99
SELECT SESSION_KEY, INPUT_TYPE, STATUS,
       TO_CHAR(START_TIME,'mm/dd/yy hh24:mi') start_time,
       TO_CHAR(END_TIME,'mm/dd/yy hh24:mi')   end_time,
       ELAPSED_SECONDS/3600                   hrs
FROM V$RMAN_BACKUP_JOB_DETAILS
ORDER BY SESSION_KEY;

9.FRA的相关信息

V$RECOVERY_FILE_DEST：提供在数据库中定义的FRA的概述。提供配置的FRA的大小、所使用的空间数量、可以回收多少空间，以及FRA中的文件数量。
V$FLASH_RECOVERY_AREA_USAGE：FRA空间各个文件类型的详细信息。

可以查看FRA占用空间的大小:

SQL> set linesize 100
SQL> col parameter for a40
SQL> col value for a40
SQL> select * from V$FLASH_RECOVERY_AREA_USAGE;

FILE_TYPE            PERCENT_SPACE_USED PERCENT_SPACE_RECLAIMABLE NUMBER_OF_FILES
-------------------- ------------------ ------------------------- ---------------
CONTROL FILE                          0                         0               0
REDO LOG                              0                         0               0
ARCHIVED LOG                       7.03 //当时环境是99%已经满了                         0               7
BACKUP PIECE                          0                         0               0
IMAGE COPY                            0                         0               0
FLASHBACK LOG                         0                         0               0
FOREIGN ARCHIVED LOG                  0                         0               0

已选择7行

10.查看Oracle数据库的进程数配置

SQL> show parameter processes;

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
aq_tm_processes                      integer     1
db_writer_processes                  integer     16
gcs_server_processes                 integer     6
global_txn_processes                 integer     1
job_queue_processes                  integer     1000
log_archive_max_processes            integer     4
processes                            integer     2000

11.Oracle数据库的可用连接数

如果是RAC数据库，会有两个值如下:

SQL> select trim(limit_value-current_utilization) from gv$resource_limit
  2  where resource_name='processes';

TRIM(LIMIT_VALUE-CURRENT_UTILIZATION)
----------------------------------------
1906
1918