转自：https://blog.csdn.net/cai_xingyun/article/details/17167281
/*查看表空间的名称及大小*/
SELECT t.tablespace_name, round(SUM(bytes / (1024 * 1024)), 0) ts_size
FROM dba_tablespaces t, dba_data_files d
WHERE t.tablespace_name = d.tablespace_name
GROUP BY t.tablespace_name;
/*查看表空间物理文件的名称及大小*/
SELECT tablespace_name,
file_id,
file_name,
round(bytes / (1024 * 1024), 0) total_space
FROM dba_data_files
ORDER BY tablespace_name;
/*查看表空间的使用情况*/
SELECT SUM(bytes) / (1024 * 1024) AS free_space, tablespace_name
FROM dba_free_space
GROUP BY tablespace_name;
SELECT a.tablespace_name,
a.bytes total,
b.bytes used,
c.bytes free,
(b.bytes * 100) / a.bytes "% USED",
(c.bytes * 100) / a.bytes "% FREE"
FROM sys.sm$ts_avail a, sys.sm$ts_used b, sys.sm$ts_free c
WHERE a.tablespace_name = b.tablespace_name
AND a.tablespace_name = c.tablespace_name;
/*查看数据库库对象*/
SELECT owner, object_type, status, COUNT(*) count#
FROM all_objects
GROUP BY owner, object_type, status;
/*查找object为哪些进程所用*/
SELECT p.spid,
s.sid,
s.type,
s.serial# serial_num,
s.username user_name,
a.type object_type,
s.osuser os_user_name,
a.owner,
a.object object_name,
decode(sign(48 - command),
1,
to_char(command),
'Action Code #' || to_char(command)) action,
p.program oracle_process,
s.terminal terminal,
s.program program,
s.status session_status
FROM v$session s, v$access a, v$process p
WHERE s.paddr = p.addr
AND s.type = 'USER'
AND a.sid = s.sid
AND a.object = 'SUBSCRIBER_ATTR'
ORDER BY s.username, s.osuser;
/*查看回滚段名称及大小*/
SELECT segment_name,
tablespace_name,
r.status,
(initial_extent / 1024) initialextent,
(next_extent / 1024) nextextent,
max_extents,
v.curext curextent
FROM dba_rollback_segs r, v$rollstat v
WHERE r.segment_id = v.usn(+)
ORDER BY segment_name;
/*查看控制文件*/
SELECT NAME FROM v$controlfile;
/*查看日志文件*/
SELECT MEMBER FROM v$logfile;
/*查看数据库的版本*/
SELECT version
FROM product_component_version
WHERE substr(product, 1, 6) = 'Oracle';
/*查看数据库的创建日期和归档方式*/
SELECT created, log_mode, log_mode FROM v$database;
/*捕捉运行很久的SQL*/
column username format a12 column opname format a16 column progress format a8
SELECT username,
sid,
opname,
round(sofar * 100 / totalwork, 0) || '%' AS progress,
time_remaining,
sql_text
FROM v$session_longops, v$sql
WHERE time_remaining <> 0
AND sql_address = address
AND sql_hash_value = hash_value;
/*查看数据表的参数信息*/
SELECT partition_name,
high_value,
high_value_length,
tablespace_name,
pct_free,
pct_used,
ini_trans,
max_trans,
initial_extent,
next_extent,
min_extent,
max_extent,
pct_increase,
freelists,
freelist_groups,
logging,
buffer_pool,
num_rows,
blocks,
empty_blocks,
avg_space,
chain_cnt,
avg_row_len,
sample_size,
last_analyzed
FROM dba_tab_partitions
--WHERE table_name = :tname AND table_owner = :towner
ORDER BY partition_position;
/*查看还没提交的事务*/
SELECT * FROM v$locked_object;
SELECT * FROM v$transaction;
/*回滚段查看*/
SELECT rownum,
sys.dba_rollback_segs.segment_namename,
v$rollstat.extents extents,
v$rollstat.rssize size_in_bytes,
v$rollstat.xacts xacts,
v$rollstat.gets gets,
v$rollstat.waits waits,
v$rollstat.writes writes,
sys.dba_rollback_segs.status status
FROM v$rollstat, sys.dba_rollback_segs, v$rollname
WHERE v$rollname.name(+) = sys.dba_rollback_segs.segment_name
AND v$rollstat.usn(+) = v$rollname.usn
ORDER BY rownum;
/*耗资源的进程（top session）*/
SELECT s.schemaname schema_name,
decode(sign(48 - command),
1,
to_char(command),
'Action Code #' || to_char(command)) action,
status session_status,
s.osuser os_user_name,
s.sid,
p.spid,
s.serial# serial_num,
nvl(s.username, '[Oracle process]') user_name,
s.terminal terminal,
s.program program,
st.value criteria_value
FROM v$sesstat st, v$session s, v$process p
WHERE st.sid = s.sid
AND st.statistic# = to_number('38')
AND ('ALL' = 'ALL' OR s.status = 'ALL')
AND p.addr = s.paddr
ORDER BY st.value DESC, p.spid ASC, s.username ASC, s.osuser ASC;
/*查看锁（lock）情况*/
SELECT /*+ RULE */
ls.osuser os_user_name,
ls.username user_name,
decode(ls.type,
'RW',
'Row wait enqueue lock',
'TM',
'DML enqueue lock',
'TX',
'Transaction enqueue lock',
'UL',
'User supplied lock') lock_type,
o.object_name OBJECT,
decode(ls.lmode,
1,
NULL,
2,
'Row Share',
3,
'Row Exclusive',
4,
'Share',
5,
'Share Row Exclusive',
6,
'Exclusive',
NULL) lock_mode,
o.owner,
ls.sid,
ls.serial# serial_num,
ls.id1,
ls.id2
FROM sys.dba_objects o,
(SELECT s.osuser,
s.username,
l.type,
l.lmode,
s.sid,
s.serial#,
l.id1,
l.id2
FROM v$session s, v$lock l
WHERE s.sid = l.sid) ls
WHERE o.object_id = ls.id1
AND o.owner <> 'SYS'
ORDER BY o.owner, o.object_name;
/*查看等待（wait）情况*/
SELECT v$waitstat.class,
v$waitstat.count COUNT,
SUM(v$sysstat.value) sum_value
FROM v$waitstat, v$sysstat
WHERE v$sysstat.name IN ('db block gets', 'consistent gets')
GROUP BY v$waitstat.class, v$waitstat.count;
/*查看SGA情况*/
SELECT NAME, bytes
FROM sys.v_$sgastat
ORDER BY NAME ASC
/*查看数据表的全部索引列*/
SELECT c.index_name, i.uniqueness, c.column_name
FROM user_indexes i, user_ind_columns c
WHERE i.index_name = c.index_name
AND i.table_name = upper('hr_locations_all')
ORDER BY c.index_name,
c.column_position
/*查看低效运行的SQL语句*/
SELECT executions,
disk_reads,
buffer_gets,
round((buffer_gets - disk_reads) / buffer_gets,
2) hit_radio,
round(disk_reads / executions, 2) reads_per_run,
sql_text
FROM v$sqlarea
WHERE executions > 0
AND buffer_gets > 0
AND (buffer_gets - disk_reads) / buffer_gets < 0.8
ORDER BY 4 DESC;
/*查询有哪些用户在使用数据库*/
SELECT username FROM v$session;
/*查看数据库的SID：*/
SELECT NAME FROM v$database;
--也可以直接查看 init.ora文件
/*如何在Oracle服务器上通过SQLPLUS查看本机IP地址 ：*/
SELECT sys_context('userenv', 'ip_address') FROM dual;