1、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;
　　

　　2、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;

　　

　　3、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 ;

　　

　　4、查看控制文件

　　select name from v$controlfile;

　　

　　5、查看日志文件

　　select member from v$logfile;

　　

　　6、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;

　　

　　7、查看数据库库对象

　　select owner, object_type, status, count(*) count# from all_objects group by owner, object_type, status;

　　

　　8、查看数据库的版本　

　　Select version FROM Product_component_version

　　Where SUBSTR(PRODUCT,1,6)=''Oracle'';

　　

　　9、查看数据库的创建日期和归档方式

　　Select Created, Log_Mode, Log_Mode From V$Database;

　　

　　10、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

　　/

　　

　　11、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

　　

　　12、查看还没提交的事务

　　select * from v$locked_object;

　　select * from v$transaction;

　　

　　13、查找object为哪些进程所用

　　select

　　p.spid,

　　s.sid,

　　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

　　

　　14、回滚段查看

　　select rownum, sys.dba_rollback_segs.segment_name Name, 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

　　

　　15、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$processp

　　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

16、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

　　

　　17、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

　　

　　18、查看sga情况

　　SELECT NAME, BYTES FROM SYS.V_$SGASTAT ORDER BY NAME ASC

　　

　　19、查看catched object

　　SELECT owner, name, db_link, namespace,

　　type, sharable_mem, loads, executions,

　　locks, pins, kept FROM v$db_object_cache

　　

　　20、查看V$SQLAREA

　　SELECT SQL_TEXT, SHARABLE_MEM, PERSISTENT_MEM, RUNTIME_MEM, SORTS,

　　VERSION_COUNT, LOADED_VERSIONS, OPEN_VERSIONS, USERS_OPENING, EXECUTIONS,

　　USERS_EXECUTING, LOADS, FIRST_LOAD_TIME, INVALIDATIONS, PARSE_CALLS, DISK_READS,

　　BUFFER_GETS, ROWS_PROCESSED FROM V$SQLAREA

　　

　　21、查看object分类数量

　　select decode (o.type#,1,''INDEX'' , 2,''TABLE'' , 3 , ''CLUSTER'' , 4, ''VIEW'' , 5 ,

　　''SYNONYM'' , 6 , ''SEQUENCE'' , ''OTHER'' ) object_type , count(*) quantity from

　　sys.obj$ o where o.type# > 1 group by decode (o.type#,1,''INDEX'' , 2,''TABLE'' , 3

　　, ''CLUSTER'' , 4, ''VIEW'' , 5 , ''SYNONYM'' , 6 , ''SEQUENCE'' , ''OTHER'' ) union select

　　''COLUMN'' , count(*) from sys.col$ union select ''DB LINK'' , count(*) from

　　

　　22、按用户查看object种类

　　select u.name schema, sum(decode(o.type#, 1, 1, NULL)) indexes,

　　sum(decode(o.type#, 2, 1, NULL)) tables, sum(decode(o.type#, 3, 1, NULL))

　　clusters, sum(decode(o.type#, 4, 1, NULL)) views, sum(decode(o.type#, 5, 1,

　　NULL)) synonyms, sum(decode(o.type#, 6, 1, NULL)) sequences,

　　sum(decode(o.type#, 1, NULL, 2, NULL, 3, NULL, 4, NULL, 5, NULL, 6, NULL, 1))

　　others from sys.obj$ o, sys.user$ u where o.type# >= 1 and u.user# =

　　o.owner# and u.name <> ''PUBLIC'' group by u.name order by

　　sys.link$ union select ''CONSTRAINT'' , count(*) from sys.con$

　　

　　23、有关connection的相关信息

　　1）查看有哪些用户连接

　　select s.osuser os_user_name, decode(sign(48 - command), 1, to_char(command),

　　''Action Code #'' 　　 to_char(command) ) action, p.program oracle_process,

　　status session_status, s.terminal terminal, s.program program,

　　s.username user_name, s.fixed_table_sequence activity_meter, '''' query,

　　0 memory, 0 max_memory, 0 cpu_usage, s.sid, s.serial# serial_num

　　from v$session s, v$process p where s.paddr=p.addr and s.type = ''USER''

　　order by s.username, s.osuser

　　2）根据v.sid查看对应连接的资源占用等情况

　　select n.name,

　　v.value,

　　n.class,

　　n.statistic#

　　from v$statname n,

　　v$sesstat v

　　where v.sid = 71 and

　　v.statistic# = n.statistic#

　　order by n.class, n.statistic#

　　3）根据sid查看对应连接正在运行的sql

　　select /*+ PUSH_SUBQ */

　　command_type,

　　sql_text,

　　sharable_mem,

　　persistent_mem,

　　runtime_mem,

　　sorts,

　　version_count,

　　loaded_versions,

　　open_versions,

　　users_opening,

　　executions,

　　users_executing,

　　loads,

　　first_load_time,

　　invalidations,

　　parse_calls,

　　disk_reads,

　　buffer_gets,

　　rows_processed,

　　sysdate start_time,

　　sysdate finish_time,

　　''>'' 　　 address sql_address,

　　''N'' status

　　from v$sqlarea

　　where address = (select sql_address from v$session where sid = 71)

　　

　　24、查询表空间使用情况select a.tablespace_name "表空间名称",

　　100-round((nvl(b.bytes_free,0)/a.bytes_alloc)*100,2) "占用率(%)",

　　round(a.bytes_alloc/1024/1024,2) "容量(M)",

　　round(nvl(b.bytes_free,0)/1024/1024,2) "空闲(M)",

　　round((a.bytes_alloc-nvl(b.bytes_free,0))/1024/1024,2) "使用(M)",

　　Largest "最大扩展段(M)",

　　to_char(sysdate,''yyyy-mm-dd hh24:mi:ss'') "采样时间"

　　from (select f.tablespace_name,

　　sum(f.bytes) bytes_alloc,

　　sum(decode(f.autoextensible,''YES'',f.maxbytes,''NO'',f.bytes)) maxbytes

　　from dba_data_files f

　　group by tablespace_name) a,

　　(select f.tablespace_name,

　　sum(f.bytes) bytes_free

　　from dba_free_space f

　　group by tablespace_name) b,

　　(select round(max(ff.length)*16/1024,2) Largest,

　　ts.name tablespace_name

　　from sys.fet$ ff, sys.file$ tf,sys.ts$ ts

　　where ts.ts#=ff.ts# and ff.file#=tf.relfile# and ts.ts#=tf.ts#

　　group by ts.name, tf.blocks) c

　　where a.tablespace_name = b.tablespace_name and a.tablespace_name = c.tablespace_name

　　

　　25、 查询表空间的碎片程度

　　select tablespace_name,count(tablespace_name) from dba_free_space group by tablespace_name

　　having count(tablespace_name)>10; 　　

　　alter tablespace name coalesce;

　　alter table name deallocate unused; 　　

　　create or replace view ts_blocks_v as

　　select tablespace_name,block_id,bytes,blocks,''free space'' segment_name from dba_free_space

　　union all

　　select tablespace_name,block_id,bytes,blocks,segment_name from dba_extents; 　　

　　select * from ts_blocks_v; 　　

　　select tablespace_name,sum(bytes),max(bytes),count(block_id) from dba_free_space

　　group by tablespace_name;