Oracle维护常用SQL语句

Posted 2021-11-27 songboblog

数据库人员手边系列：Oracle维护常用SQL语句

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$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

　　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; 26.查看表空间利用率的脚本 select tablespace_name,sqrt(max(blocks)/sum(blocks))* (100/sqrt(sqrt(count(blocks)))) FSFI from dba_free_space group by tablespace_name order by 1; 27. 查看活动连接情况 select t.SQL_HASH_VALUE, t. *   from v$session t where t.USERNAME = ‘RKXT‘    and t.STATUS = ‘ACTIVE‘

28.　长时间操作语句 select t.SQL_HASH_VALUE, t.*   from V$SESSION_LONGOPS T where t.SOFAR <> t.TOTALWORK

29. 查看完整的语句文本 select * from v$sqltext t where t.HASH_VALUE = 3873527576 order by t.PIECE

30.不合法数据清理 select ‘delete from rkxt.‘||t.table_name||‘ where slsj > to_char(sysdate+1, ‘‘yyyymmdd‘‘) and slrxm is null;‘   from dba_tab_cols t where t.owner = ‘RKXT‘    and t.column_name like ‘SLSJ‘

31.数据库分析脚本 select ‘exec dbms_stats.gather_table_stats(ownname => user,tabname => ‘‘‘ ||        T.table_name ||        ‘‘‘, estimate_percent => 1,method_opt => ‘‘for all indexed columns size skewonly‘‘, cascade => true, degree => 4);‘        ,t.*   from user_tables t where (t.last_analyzed is null or        t.last_analyzed < to_date(‘20060808‘, ‘yyyymmdd‘));

32.查看最近有哪些用户执行过哪些语句。 select distinct     a.SCHEMANAME,     a.OSUSER,     a.PROGRAM,     a.ACTION,     b.sql_text from v$session a,     v$sql b where b.PARSING_USER_ID=a.SCHEMA#   and   a.SCHEMA#!=0

关于SCN select dbms_flashback.get_system_change_number from dual ; 这可以得到当前的SCN. select checkpoint_change# from $database; 这可以得到系统的SCN. select checkpoint_change# from v$datafile_header ; 这可以得到文件头的SCN select checkpoint_change# from v$datafile 这可以得到在控制文件中,数据文件的SCN.

33.杀掉不合理的用户进程 select ‘alter system kill session ‘‘‘ || t.sid || ‘,‘ || t.SERIAL# || ‘‘‘;‘,        t.PROGRAM,        t.SQL_HASH_VALUE,        t. *   from v$session t where t.USERNAME = ‘RKXT_SX‘    and t.STATUS = ‘ACTIVE‘; 34.如何查看一个表的大小 Select Sum(a.bytes)/(1024*1024*1024) As total,‘G‘,a.segment_name,a.tablespace_name From dba_segments a,Dba_All_Tables b Where a.owner = ‘LT‘ And a.segment_name = b.table_name And a.segment_type = ‘TABLE‘ and table_name = ‘你要查的表‘ Group By a.segment_name,a.tablespace_name Order By total Desc

--监控索引是否使用 alter index &index_name monitoring usage; alter index &index_name nomonitoring usage; select * from v$object_usage where index_name = &index_name;

 

--求数据文件的I/O分布 select df.name,phyrds,phywrts,phyblkrd,phyblkwrt,singleblkrds,readtim,writetim from v$filestat fs,v$dbfile df where fs.file#=df.file# order by df.name;

--求某个隐藏参数的值 col ksppinm format a54 col ksppstvl format a54 select ksppinm, ksppstvl from x$ksppi pi, x$ksppcv cv where cv.indx=pi.indx and pi.ksppinm like ‘_%‘ escape ‘‘ and pi.ksppinm like ‘%&parameer%‘;

--求系统中较大的latch select name,sum(gets),sum(misses),sum(sleeps),sum(wait_time) from v$latch_children group by name having sum(gets) > 50 order by 2;

--求归档日志的切换频率(生产系统可能时间会很长) select start_recid,start_time,end_recid,end_time,minutes from (select test.*, rownum as rn from (select b.recid start_recid,to_char(b.first_time,‘yyyy-mm-dd hh24:mi:ss‘) start_time, a.recid end_recid,to_char(a.first_time,‘yyyy-mm-dd hh24:mi:ss‘) end_time,round(((a.first_time-b.first_time)*24)*60,2) minutes from v$log_history a,v$log_history b where a.recid=b.recid+1 and b.first_time > sysdate - 1 order by a.first_time desc) test) y where y.rn < 30

--求回滚段正在处理的事务 select a.name,b.xacts,c.sid,c.serial#,d.sql_text from v$rollname a,v$rollstat b,v$session c,v$sqltext d,v$transaction e where a.usn=b.usn and b.usn=e.xidusn and c.taddr=e.addr and c.sql_address=d.address and c.sql_hash_value=d.hash_value order by a.name,c.sid,d.piece;

--求出无效的对象 select ‘alter procedure ‘||object_name||‘ compile;‘ from dba_objects where status=‘INVALID‘ and owner=‘&‘ and object_type in (‘PACKAGE‘,‘PACKAGE BODY‘); / select owner,object_name,object_type,status from dba_objects where status=‘INVALID‘;

--求process/session的状态 select p.pid,p.spid,s.program,s.sid,s.serial# from v$process p,v$session s where s.paddr=p.addr;

--求当前session的状态 select sn.name,ms.value from v$mystat ms,v$statname sn where ms.statistic#=sn.statistic# and ms.value > 0;

--求表的索引信息 select ui.table_name,ui.index_name from user_indexes ui,user_ind_columns uic where ui.table_name=uic.table_name and ui.index_name=uic.index_name and ui.table_name like ‘&table_name%‘ and uic.column_name=‘&column_name‘;

--显示表的外键信息 col search_condition format a54 select table_name,constraint_name from user_constraints where constraint_type =‘R‘ and constraint_name in (select constraint_name from user_cons_columns where column_name=‘&1‘);

select rpad(child.table_name,25,‘ ‘) child_tablename, rpad(cp.column_name,17,‘ ‘) referring_column,rpad(parent.table_name,25,‘ ‘) parent_tablename, rpad(pc.column_name,15,‘ ‘) referred_column,rpad(child.constraint_name,25,‘ ‘) constraint_name from user_constraints child,user_constraints parent, user_cons_columns cp,user_cons_columns pc where child.constraint_type = ‘R‘ and child.r_constraint_name = parent.constraint_name and child.constraint_name = cp.constraint_name and parent.constraint_name = pc.constraint_name and cp.position = pc.position and child.table_name =‘&table_name‘ order by child.owner,child.table_name,child.constraint_name,cp.position;

--显示表的分区及子分区(user_tab_subpartitions) col table_name format a16 col partition_name format a16 col high_value format a81 select table_name,partition_name,HIGH_VALUE from user_tab_partitions where table_name=‘&table_name‘

--使用dbms_xplan生成一个执行计划 explain plan set statement_id = ‘&sql_id‘ for &sql; select * from table(dbms_xplan.display);

--求某个事务的重做信息(bytes) select s.name,m.value from v$mystat m,v$statname s where m.statistic#=s.statistic# and s.name like ‘%redo size%‘;

--求cache中缓存超过其5%的对象 select o.owner,o.object_type,o.object_name,count(b.objd) from v$bh b,dba_objects o where b.objd = o.object_id group by o.owner,o.object_type,o.object_name having count(b.objd) > (select to_number(value)*0.05 from v$parameter where name = ‘db_block_buffers‘);

--求谁阻塞了某个session(10g) select sid, username, event, blocking_session, seconds_in_wait, wait_time from v$session where state in (‘WAITING‘) and wait_class != ‘Idle‘;

--求session的OS进程ID col program format a54 select p.spid "OS Thread", b.name "Name-User", s.program from v$process p, v$session s, v$bgprocess b where p.addr = s.paddr and p.addr = b.paddr UNION ALL select p.spid "OS Thread", s.username "Name-User", s.program from v$process p, v$session s where p.addr = s.paddr and s.username is not null;

--查会话的阻塞 col user_name format a32 select /*+ rule */ lpad(‘ ‘,decode(l.xidusn ,0,3,0))||l.oracle_username user_name, o.owner,o.object_name,s.sid,s.serial# from v$locked_object l,dba_objects o,v$session s where l.object_id=o.object_id and l.session_id=s.sid order by o.object_id,xidusn desc ;

col username format a15 col lock_level format a8 col owner format a18 col object_name format a32 select /*+ rule */ s.username, decode(l.type,‘tm‘,‘table lock‘, ‘tx‘,‘row lock‘, null) lock_level, o.owner,o.object_name,s.sid,s.serial# from v$session s,v$lock l,dba_objects o where l.sid = s.sid and l.id1 = o.object_id(+) and s.username is not null ;

--求等待的事件及会话信息/求会话的等待及会话信息 select se.sid,s.username,se.event,se.total_waits,se.time_waited,se.average_wait from v$session s,v$session_event se where s.username is not null and se.sid=s.sid and s.status=‘ACTIVE‘ and se.event not like ‘%SQL*Net%‘ order by s.username;

select s.sid,s.username,sw.event,sw.wait_time,sw.state,sw.seconds_in_wait from v$session s,v$session_wait sw where s.username is not null and sw.sid=s.sid and sw.event not like ‘%SQL*Net%‘ order by s.username;

--求会话等待的file_id/block_id col event format a24 col p1text format a12 col p2text format a12 col p3text format a12 select sid,event,p1text, p1, p2text, p2, p3text, p3 from v$session_wait where event not like ‘%SQL%‘ and event not like ‘%rdbms%‘ and event not like ‘%mon%‘ order by event;

select name,wait_time from v$latch l where exists (select 1 from (select sid,event,p1text, p1, p2text, p2, p3text, p3 from v$session_wait where event not like ‘%SQL%‘ and event not like ‘%rdbms%‘ and event not like ‘%mon%‘ ) x where x.p1= l.latch#);

--求会话等待的对象 col owner format a18 col segment_name format a32 col segment_type format a32 select owner,segment_name,segment_type from dba_extents where file_id = &file_id and &block_id between block_id and block_id + blocks - 1;

--求buffer cache中的块信息 select o.OBJECT_TYPE, substr(o.OBJECT_NAME,1,10) objname , b.objd , b.status, count(b.objd) from v$bh b, dba_objects o where b.objd = o.data_object_id and o.owner = ‘&1‘ group by o.object_type, o.object_name,b.objd, b.status ;

--求日志文件的空间使用 select le.leseq current_log_sequence#, 100*cp.cpodr_bno/le.lesiz percentage_full from x$kcccp cp,x$kccle le where le.leseq =cp.cpodr_seq;

--求等待中的对象 select /*+rule */ s.sid, s.username, w.event, o.owner, o.segment_name, o.segment_type, o.partition_name, w.seconds_in_wait seconds, w.state from v$session_wait w, v$session s, dba_extents o where w.event in (select name from v$event_name where parameter1 = ‘file#‘ and parameter2 = ‘block#‘ and name not like ‘control%‘) and o.owner <> ‘sys‘ and w.sid = s.sid and w.p1 = o.file_id and w.p2 >= o.block_id and w.p2 < o.block_id + o.blocks

--求当前事务的重做尺寸 select value from v$mystat, v$statname where v$mystat.statistic# = v$statname.statistic# and v$statname.name = ‘redo size‘;

--唤醒smon去清除临时段 column pid new_value Smon set termout off select p.pid from sys.v_$bgprocess b,sys.v_$process p where b.name = ‘SMON‘ and p.addr = b.paddr / set termout on oradebug wakeup &Smon undefine Smon

--求回退率 select b.value/(a.value + b.value),a.value,b.value from v$sysstat a,v$sysstat b where a.statistic#=4 and b.statistic#=5;

--求DISK READ较多的SQL select st.sql_text from v$sql s,v$sqltext st where s.address=st.address and s.hash_value=st.hash_value and s.disk_reads > 300;

--求DISK SORT严重的SQL select sess.username, sql.sql_text, sort1.blocks from v$session sess, v$sqlarea sql, v$sort_usage sort1 where sess.serial# = sort1.session_num and sort1.sqladdr = sql.address and sort1.sqlhash = sql.hash_value and sort1.blocks > 200;

--求对象的创建代码 column column_name format a36 column sql_text format a99 select dbms_metadata.get_ddl(‘TABLE‘,‘&1‘) from dual; select dbms_metadata.get_ddl(‘INDEX‘,‘&1‘) from dual;

--求表的索引 set linesize 131 select a.index_name,a.column_name,b.status, b.index_type from user_ind_columns a,user_indexes b where a.index_name=b.index_name and a.table_name=‘&1‘;

求索引中行数较多的 select index_name,blevel,num_rows,CLUSTERING_FACTOR,status from user_indexes where num_rows > 10000 and blevel > 0 select table_name,index_name,blevel,num_rows,CLUSTERING_FACTOR,status from user_indexes where status <> ‘VALID‘

--求当前会话的SID，SERIAL# select sid, serial# from v$session where audsid = SYS_CONTEXT(‘USERENV‘,‘SESSIONID‘);

--求表空间的未用空间 col mbytes format 9999.9999 select tablespace_name,sum(bytes)/1024/1024 mbytes from dba_free_space group by tablespace_name;

--求表中定义的触发器 select table_name,index_type,index_name,uniqueness from user_indexes where table_name=‘&1‘; select trigger_name from user_triggers where table_name=‘&1‘;

--求未定义索引的表 select table_name from user_tables where table_name not in (select table_name from user_ind_columns);

--执行常用的过程 exec print_sql(‘select count(*) from tab‘); exec show_space2(‘table_name‘);

--求free memory select * from v$sgastat where name=‘free memory‘; select a.name,sum(b.value) from v$statname a,v$sesstat b where a.statistic# = b.statistic# group by a.name;

查看一下谁在使用那个可以得回滚段，或者查看一下某个可以得用户在使用回滚段，找出领回滚段不断增长的事务，再看看如何处理它，是否可以将它commit，再不行就看看能否kill它，等等, 查看当前正在使用的回滚段的用户信息和回滚段信息: set linesize 121 SELECT r.name "ROLLBACK SEGMENT NAME ",l.sid "ORACLE PID",p.spid "SYSTEM PID ",s.username "ORACLE USERNAME" FROM v$lock l, v$process p, v$rollname r, v$session s WHERE l.sid = p.pid(+) AND s.sid=l.sid AND TRUNC(l.id1(+)/65536) = r.usn AND l.type(+) = ‘TX‘ AND l.lmode(+) = 6 ORDER BY r.name;

--查看用户的回滚段的信息 select s.username, rn.name from v$session s, v$transaction t, v$rollstat r, v$rollname rn where s.saddr = t.ses_addr and t.xidusn = r.usn and r.usn = rn.usn

--生成执行计划 explain plan set statement_id=‘a1‘ for &1; --查看执行计划 select lpad(‘ ‘,2*(level-1))||operation operation,options,OBJECT_NAME,position from plan_table start with id=0 and statement_id=‘a1‘ connect by prior id=parent_id and statement_id=‘a1‘

--查看内存中存的使用 select decode(greatest(class,10),10,decode(class,1,‘Data‘,2,‘Sort‘,4,‘Header‘,to_char(class)),‘Rollback‘) "Class", sum(decode(bitand(flag,1),1,0,1)) "Not Dirty",sum(decode(bitand(flag,1),1,1,0)) "Dirty", sum(dirty_queue) "On Dirty",count(*) "Total" from x$bh group by decode(greatest(class,10),10,decode(class,1,‘Data‘,2,‘Sort‘,4,‘Header‘,to_char(class)),‘Rollback‘);

-- 查看表空间状态 select tablespace_name,extent_management,segment_space_management from dba_tablespaces; select table_name,freelists,freelist_groups from user_tables;

--查看系统请求情况 SELECT DECODE (name, ‘summed dirty write queue length‘, value)/ DECODE (name, ‘write requests‘, value) "Write Request Length" FROM v$sysstat WHERE name IN ( ‘summed dirty queue length‘, ‘write requests‘) and value>0;

--计算data buffer 命中率 select a.value + b.value "logical_reads", c.value "phys_reads", round(100 * ((a.value+b.value)-c.value) / (a.value+b.value)) "BUFFER HIT RATIO" from v$sysstat a, v$sysstat b, v$sysstat c where a.statistic# = 40 and b.statistic# = 41 and c.statistic# = 42;

SELECT name, (1-(physical_reads/(db_block_gets+consistent_gets)))*100 H_RATIO FROM v$buffer_pool_statistics;

--查看内存使用情况 select least(max(b.value)/(1024*1024),sum(a.bytes)/(1024*1024)) shared_pool_used, max(b.value)/(1024*1024) shared_pool_size,greatest(max(b.value)/(1024*1024),sum(a.bytes)/(1024*1024))- (sum(a.bytes)/(1024*1024)) shared_pool_avail,((sum(a.bytes)/(1024*1024))/(max(b.value)/(1024*1024)))*100 avail_pool_pct from v$sgastat a, v$parameter b where (a.pool=‘shared pool‘ and a.name not in (‘free memory‘)) and b.name=‘shared_pool_size‘;

--查看用户使用内存情况 select username, sum(sharable_mem), sum(persistent_mem), sum(runtime_mem) from sys.v_$sqlarea a, dba_users b where a.parsing_user_id = b.user_id group by username;

--查看对象的缓存情况 select OWNER,NAMESPACE,TYPE,NAME,SHARABLE_MEM,LOADS,EXECUTIONS,LOCKS,PINS,KEPT from v$db_object_cache where type not in (‘NOT LOADED‘,‘NON-EXISTENT‘,‘VIEW‘,‘TABLE‘,‘SEQUENCE‘) and executions>0 and loads>1 and kept=‘NO‘ order by owner,namespace,type,executions desc;

select type,count(*) from v$db_object_cache group by type;

--查看库缓存命中率 select namespace,gets, gethitratio*100 gethitratio,pins,pinhitratio*100 pinhitratio,RELOADS,INVALIDATIONS from v$librarycache

--查看某些用户的hash select a.username, count(b.hash_value) total_hash,count(b.hash_value)-count(unique(b.hash_value)) same_hash, (count(unique(b.hash_value))/count(b.hash_value))*100 u_hash_ratio from dba_users a, v$sqlarea b where a.user_id=b.parsing_user_id group by a.username;

--查看字典命中率 select (sum(getmisses)/sum(gets)) ratio from v$rowcache;

--查看undo段的使用情况 SELECT d.segment_name,extents,optsize,shrinks,aveshrink,aveactive,d.status FROM v$rollname n,v$rollstat s,dba_rollback_segs d WHERE d.segment_id=n.usn(+) and d.segment_id=s.usn(+);

--无效的对象 select owner,object_type,object_name from dba_objects where status=‘INVALID‘; select constraint_name,table_name from dba_constraints where status=‘INVALID‘;

--求出某个进程，并对它进行跟踪 select s.sid,s.serial# from v$session s,v$process p where s.paddr=p.addr and p.spid=&1; exec dbms_system.SET_SQL_TRACE_IN_SESSION(&1,&2,true); exec dbms_system.SET_SQL_TRACE_IN_SESSION(&1,&2,false);

--求出锁定的对象 select do.object_name,session_id,process,locked_mode from v$locked_object lo, dba_objects do where lo.object_id=do.object_id;

--求当前session的跟踪文件 SELECT p1.value || ‘/‘ || p2.value || ‘_ora_‘ || p.spid || ‘.ora‘ filename FROM v$process p, v$session s, v$parameter p1, v$parameter p2 WHERE p1.name = ‘user_dump_dest‘ AND p2.name = ‘instance_name‘ AND p.addr = s.paddr AND s.audsid = USERENV(‘SESSIONID‘) AND p.background is null AND instr(p.program,‘CJQ‘) = 0;

--求对象所在的文件及块号 select segment_name,header_file,header_block from dba_segments where segment_name like ‘&1‘;

--求对象发生事务时回退段及块号 select a.segment_name,a.header_file,a.header_block from dba_segments a,dba_rollback_segs b where a.segment_name=b.segment_name and b.segment_id=‘&1‘

--9i的在线重定义表 /*如果在线重定义的表没有主键需要创建主键*/ exec dbms_redefinition.can_redef_table(‘cybercafe‘,‘announcement‘); create table anno2 as select * from announcement exec dbms_redefinition.start_redef_table(‘cybercafe‘,‘announcement‘,‘anno2‘); exec dbms_redefinition.sync_interim_table(‘cybercafe‘,‘announcement‘,‘anno2‘); exec dbms_redefinition.finish_redef_table(‘cybercafe‘,‘announcement‘,‘anno2‘); drop table anno2 exec dbms_redefinition.abort_redef_table(‘cybercafe‘,‘announcement‘,‘anno2‘);

--常用的logmnr脚本(cybercafe) exec sys.dbms_logmnr_d.build(dictionary_filename =>‘esal‘,dictionary_location =>‘/home/oracle/logmnr‘); exec sys.dbms_logmnr.add_logfile(logfilename=>‘/home/oracle/oradata/esal/archive/1_24050.dbf‘, options=>sys.dbms_logmnr.new);

exec sys.dbms_logmnr.add_logfile(logfilename=>‘/home/oracle/oradata/esal/archive/1_22912.dbf‘, options=>sys.dbms_logmnr.addfile); exec sys.dbms_logmnr.add_logfile(logfilename=>‘/home/oracle/oradata/esal/archive/1_22913.dbf‘, options=>sys.dbms_logmnr.addfile); exec sys.dbms_logmnr.add_logfile(logfilename=>‘/home/oracle/oradata/esal/archive/1_22914.dbf‘, options=>sys.dbms_logmnr.addfile);

exec sys.dbms_logmnr.start_logmnr(dictfilename=>‘/home/oracle/logmnr/esal.ora‘); create table logmnr2 as select * from v$logmnr_contents;

--与权限相关的字典 ALL_COL_PRIVS 表示列上的授权，用户和PUBLIC是被授予者 ALL_COL_PRIVS_MADE 表示列上的授权，用户是属主和被授予者 ALL_COL_RECD 表示列上的授权，用户和PUBLIC是被授予者 ALL_TAB_PRIVS 表示对象上的授权，用户是PUBLIC或被授予者或用户是属主 ALL_TAB_PRIVS_MADE 表示对象上的权限，用户是属主或授予者 ALL_TAB_PRIVS_RECD 表示对象上的权限, 用户是PUBLIC或被授予者 DBA_COL_PRIVS 数据库列上的所有授权 DBA_ROLE_PRIVS 显示已授予用户或其他角色的角色 DBA_SYS_PRIVS 已授予用户或角色的系统权限 DBA_TAB_PRIVS 数据库对象上的所有权限 ROLE_ROLE_PRIVS 显示已授予用户的角色 ROLE_SYS_PRIVS 显示通过角色授予用户的系统权限 ROLE_TAB_PRIVS 显示通过角色授予用户的对象权限 SESSION_PRIVS 显示用户现在可利用的所有系统权限 USER_COL_PRIVS 显示列上的权限，用户是属主、授予者或被授予者 USER_COL_PRIVS_MADE 显示列上已授予的权限，用户是属主或授予者 USER_COL_PRIVS_RECD 显示列上已授予的权限，用户是属主或被授予者 USER_ROLE_PRIVS 显示已授予给用户的所有角色 USER_SYS_PRIVS 显示已授予给用户的所有系统权限 USER_TAB_PRIVS 显示已授予给用户的所有对象权限 USER_TAB_PRIVS_MADE 显示已授予给其他用户的对象权限，用户是属主 USER_TAB_PRIVS_RECD 显示已授予给其他用户的对象权限，用户是被授予者

--如何用dbms_stats分析表及模式？ exec dbms_stats.gather_schema_stats(ownname=>‘&USER_NAME‘,estimate_percent=>dbms_stats.auto_sample_size, method_opt => ‘for all columns size auto‘,degree=> DBMS_STATS.DEFAULT_DEGREE); exec dbms_stats.gather_schema_stats(ownname=>‘&USER_NAME‘,estimate_percent=>dbms_stats.auto_sample_size,cascade=>true); /* FOR ALL [INDEXED | HIDDEN] COLUMNS [size_clause] FOR COLUMNS [size clause] column|attribute [size_clause] [,column|attribute [size_clause]...], where size_clause is defined as size_clause := SIZE {integer | REPEAT | AUTO | SKEWONLY} integer--Number of histogram buckets. Must be in the range [1,254]. REPEAT--Collects histograms only on the columns that already have histograms. AUTO--Oracle determines the columns to collect histograms based on data distribution and the workload of the columns. SKEWONLY--Oracle determines the columns to collect histograms based on the data distribution of the columns */

 

查询_开头的隐含参数: select x.ksppinm name,        y.ksppstvl value,        y.ksppstdf isdefault,        decode(bitand(y.ksppstvf, 7),               1,               ‘MODIFIED‘,               4,               ‘SYSTEM_MOD‘,               ‘FALSE‘) ismod,        decode(bitand(y.ksppstvf, 2), 2, ‘TRUE‘, ‘FALSE‘) isadj   from x$ksppi x, x$ksppcv y where x.inst_id = userenv(‘Instance‘)    and y.inst_id = userenv(‘Instance‘)    and x.indx = y.indx    and x.ksppinm like ‘%_&par%‘ order by translate(x.ksppinm, ‘_‘, ‘‘)

查看数据字典表名及内容 select * from dict

测试响应时间语句 select t.CPU_TIME / t.EXECUTIONS / 1000000, t.HASH_VALUE, t.*   from v$sql t where t.LAST_LOAD_TIME > ‘2006-08-07‘    and t.EXECUTIONS <> 0 order by 1 desc