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判斷回滾段競(jìng)爭(zhēng)的SQL語句：（當(dāng)Ratio大于2時(shí)存在回滾段競(jìng)爭(zhēng)，需要增加更多的回滾段）
select rn.name, rs.GETS, rs.WAITS, (rs.WAITS / rs.GETS) * 100 ratio from v$rollstat rs, v$rollname rn where rs.USN = rn.usn 判斷恢復(fù)日志競(jìng)爭(zhēng)的SQL語句：（immediate_contention或wait_contention的值大于1時(shí)存在競(jìng)爭(zhēng)）
select name, (t.IMMEDIATE_MISSES / decode((t.IMMEDIATE_GETS t.IMMEDIATE_MISSES), 0, -1, (t.IMMEDIATE_GETS t.IMMEDIATE_MISSES))) * 100 immediate_contention, (t.MISSES / decode((t.GETS t.MISSES), 0, -1, (t.GETS t.MISSES))) * 100 wait_contention from v$latch t where name in ('redo copy', 'redo allocation') 判斷表空間碎片：（如果最大空閑空間占總空間很大比例則可能不存在碎片，如果比例較小，且有許多空閑空間，則可能碎片很多）
select t.tablespace_name, sum(t.bytes), max(t.bytes), count(*), max(t.bytes) / sum(t.bytes) radio from dba_free_space t group by t.tablespace_name order by t.tablespace_name 確定命中排序域的次數(shù)：
select t.NAME, t.VALUE from v$sysstat t where t.NAME like 'sort%' 查看當(dāng)前SGA值：
select * from v$sga 確定高速緩沖區(qū)命中率：（如果命中率低于70％，則應(yīng)該加大init.ora參數(shù)中的DB_BLOCK_BUFFER的值）
select 1 - sum(decode(name, 'physical reads', value, 0)) / (sum(decode(name, 'db block gets', value, 0)) sum(decode(name, 'consistent gets', value, 0))) hit_ratio from v$sysstat t where name in ('physical reads', 'db block gets', 'consistent gets') 確定共享池中的命中率：（如果ratio1大于1時(shí)，需要加大共享池，如果ratio2大于10％時(shí)，需要加大共享池SHARED_POOL_SIZE）
select sum(pins) pins, sum(reloads) reloads, (sum(reloads) / sum(pins)) * 100 ratio1 from v$librarycache select sum(gets) gets,
sum(getmisses) getmisses, (sum(getmisses) / sum(gets)) * 100 ratio2 from v$rowcache 查詢INIT.ORA參數(shù)：
select * from v$parameter /////
Oracle性能參數(shù)查看（轉(zhuǎn)） 0、數(shù)據(jù)庫參數(shù)屬性 col PROPERTY_NAME format a25 col PROPERTY_VALUE format a30 col DESCRIPTION format a100 select * from database_properties; select * from v$version; 1、求當(dāng)前會(huì)話的SID，SERIAL# SELECT Sid, Serial# FROM V$session WHERE Audsid = Sys_Context('USERENV', 'SESSIONID'); 2、查詢session的OS進(jìn)程ID SELECT p.Spid "OS Thread", b.NAME "Name-User", s.Program, s.Sid, s.Serial#,s.Osuser, s.Machine FROM V$process p, V$session s, V$bgprocess b WHERE p.Addr = s.Paddr AND p.Addr = b.Paddr And (s.sid=&1 or p.spid=&1) UNION ALL SELECT p.Spid "OS Thread", s.Username "Name-User", s.Program, s.Sid,s.Serial#, s.Osuser, s.Machine FROM V$process p, V$session s WHERE p.Addr = s.Paddr And (s.sid=&1 or p.spid=&1) AND s.Username IS NOT NULL; 3、根據(jù)sid查看對(duì)應(yīng)連接正在運(yùn)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 = &sid ); 4、查找object為哪些進(jìn)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$process p WHERE s.Paddr = p.Addr AND s.TYPE = 'USER' AND a.Sid = s.Sid AND a.OBJECT = '&obj' ORDER BY s.Username, s.Osuser 5、查看有哪些用戶連接
SELECT s.Osuser Os_User_Name,Decode(Sign(48 - Command),1,To_Char(Command), 'Action Code #' || To_Char(Command)) Action, p.Program Oracle_Process, Status Session_Status, s.Terminal Terminal, s.Program Program, s.Username User_Name, s.Fixed_Table_Sequence Activity_Meter, '' Query, 0 Memory, 0 Max_Memory, 0 Cpu_Usage, s.Sid, s.Serial# Serial_Num FROM V$session s, V$process p WHERE s.Paddr = p.Addr AND s.TYPE = 'USER' ORDER BY s.Username, s.Osuser 6、根據(jù)v.sid查看對(duì)應(yīng)連接的資源占用等情況
SELECT n.NAME, v.VALUE, n.CLASS, n.Statistic# FROM V$statname n, V$sesstat v WHERE v.Sid = &sid AND v.Statistic# = n.Statistic# ORDER BY n.CLASS, n.Statistic# 7、查詢耗資源的進(jìn)程（top session）
SELECT s.Schemaname Schema_Name,Decode(Sign(48 - Command), 1, To_Char(Command), 'Action Code #' || To_Char(Command)) Action,Status Session_Status, s.Osuser Os_User_Name, s.Sid, p.Spid,s.Serial# Serial_Num, Nvl(s.Username, '[Oracle process]') User_Name, s.Terminal Terminal, s.Program Program, St.VALUE Criteria_Value FROM V$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 8、查看鎖（lock）情況
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; 9、查看等待（wait）情況 SELECT Ws.CLASS, Ws.COUNT COUNT, SUM(Ss.VALUE) Sum_Value FROM V$waitstat Ws, V$sysstat Ss WHERE Ss.NAME IN ('db block gets', 'consistent gets') GROUP BY Ws.CLASS, Ws.COUNT; 10、求process/session的狀態(tài)
SELECT p.Pid, p.Spid, s.Program, s.Sid, s.Serial# FROM V$process p, V$session s WHERE s.Paddr = p.Addr; 11、求誰阻塞了某個(gè)session(10g)
SELECT Sid, Username, Event, Blocking_Session, Seconds_In_Wait, Wait_Time FROM V$session WHERE State IN ('WAITING') AND Wait_Class != 'Idle'; 12、查會(huì)話的阻塞
col user_name format a32 SELECT /* rule */ Lpad(' ', Decode(l.Xidusn, 0, 3, 0)) || l.Oracle_Username User_Name, o.Owner, o.Object_Name, s.Sid, s.Serial# FROM V$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$lock l, Dba_Objects o WHERE l.Sid = s.Sid AND l.Id1 = o.Object_Id( ) AND s.Username IS NOT NULL; 13、求等待的事件及會(huì)話信息/求會(huì)話的等待及會(huì)話信息
SELECT Se.Sid, s.Username, Se.Event, Se.Total_Waits, Se.Time_Waited,Se.Average_Wait FROM V$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$session_Wait Sw WHERE s.Username IS NOT NULL AND Sw.Sid = s.Sid AND Sw.Event NOT LIKE '%SQL*Net%' ORDER BY s.Username; 14、求會(huì)話等待的file_id/block_id
col event format a24 col p1text format a12 col p2text format a12 col p3text format a12 SELECT Sid, Event, P1text, P1, P2text, P2, P3text, P3 FROM V$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#); 15、求會(huì)話等待的對(duì)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; 16、求出某個(gè)進(jìn)程，并對(duì)它進(jìn)行跟蹤
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); 17、求當(dāng)前session的跟蹤文件
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; 18、求出鎖定的對(duì)象
SELECT Do.Object_Name, Session_Id, Process, Locked_Mode FROM V$locked_Object Lo, Dba_Objects Do WHERE Lo.Object_Id = Do.Object_Id; 19、DB_Cache建議 SELECT size_for_estimate, buffers_for_estimate, estd_physical_read_factor, estd_physical_reads FROM V$DB_CACHE_ADVICE WHERE name = 'DEFAULT' AND block_size = (SELECT value FROM V$PARAMETER WHERE name = 'db_block_size') AND advice_status = 'ON'; 20、查看各項(xiàng)SGA相關(guān)參數(shù)：SGA，SGASTAT select substr(name,1,10) name,substr(value,1,10) value from v$parameter where name = 'log_buffer'; select * from v$sgastat ; select * from v$sga; show parameters area_size #查看 各項(xiàng)區(qū)域內(nèi)存參數(shù)， 其中sort_area為排序參數(shù)用； 各項(xiàng)視圖建議參數(shù)值：V$DB_CACHE_ADVICE、V$SHARED_POOL_ADVICE），關(guān)于PGA 也有相關(guān)視圖V$PGA_TARGET_ADVICE 等。 21、內(nèi)存使用鎖定在物理內(nèi)存： AIX 5L（AIX 4.3.3 以上） logon aix as root cd /usr/samples/kernel ./vmtune (信息如下) v_pingshm已經(jīng)是1 ./vmtune -S 1 然后oracle用戶修改initSID.ora 中 lock_sga = true 重新啟動(dòng)數(shù)據(jù)庫 HP UNIX Root身份登陸 Create the file "/etc/privgroup": vi /etc/privgroup Add line "dba MLOCK" to file As root, run the command "/etc/setprivgrp -f /etc/privgroup": $/etc/setprivgrp -f /etc/privgroup oracle用戶修改initSID.ora中l(wèi)ock_sga=true 重新啟動(dòng)數(shù)據(jù)庫 SOLARIS (solaris2.6以上) 8i版本以上數(shù)據(jù)庫默認(rèn)使用隱藏參數(shù) use_ism = true ，自動(dòng)鎖定SGA于內(nèi)存中,不用設(shè)置 lock_sga, 如果設(shè)置 lock_sga =true 使用非 root 用戶啟動(dòng)數(shù)據(jù)庫將返回錯(cuò)誤。 WINDOWS （作用不大） 不能設(shè)置lock_sga=true,可以通過設(shè)置pre_page_sga=true,使得數(shù)據(jù)庫啟動(dòng)的時(shí)候就把所有內(nèi) 存頁裝載，這樣可能起到一定的作用。 22、內(nèi)存參數(shù)調(diào)整 數(shù)據(jù)緩沖區(qū)命中率 select value from v$sysstat where name ='physical reads'; select value from v$sysstat where name ='physical reads direct'; select value from v$sysstat where name ='physical reads direct (lob)'; select value from v$sysstat where name ='consistent gets'; select value from v$sysstat where name = 'db block gets'; 這里命中率的計(jì)算應(yīng)該是 令 x = physical reads direct physical reads direct (lob) 命中率 =100 - ( physical reads - x) / (consistent gets db block gets - x)*100 通常如果發(fā)現(xiàn)命中率低于90%,則應(yīng)該調(diào)整應(yīng)用可可以考慮是否增大數(shù)據(jù)緩沖區(qū)； 共享池的命中率 select sum(pinhits)/sum(pins)*100 "hit radio" from v$librarycache; 假如共享池的命中率低于95%,就要考慮調(diào)整應(yīng)用（通常是沒使用bind var ）或者增加內(nèi)存； 關(guān)于排序部分 select name,value from v$sysstat where name like '%sort%'; 假如我們發(fā)現(xiàn)sorts (disk)/ (sorts (memory) sorts (disk))的比例過高，則通常意味著 sort_area_size 部分內(nèi)存較小，可考慮調(diào)整相應(yīng)的參數(shù)。 關(guān)于log_buffer select name,value from v$sysstat where name in('redo entries','redo buffer allocation retries'); 假如 redo buffer allocation retries/ redo entries 的比例超過1%我們就可以考慮增大log_buffer ///// July 28 oracle 常用SQL查詢，望對(duì)大家有所啟示 1、查看表空間的名稱及大小 select t.tablespace_name, round(sum(bytes/(1024*1024)),0) ts_size from dba_tablespaces t, dba_data_files d where t.tablespace_name = d.tablespace_name group by t.tablespace_name; 2、查看表空間物理文件的名稱及大小 select tablespace_name, file_id, file_name, round(bytes/(1024*1024),0) total_space from dba_data_files order by tablespace_name; 3、查看回滾段名稱及大小 select segment_name, tablespace_name, r.status, (initial_extent/1024) InitialExtent,(next_extent/1024) NextExtent, max_extents, v.curext CurExtent From dba_rollback_segs r, v$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、查看表空間的使用情況 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$TS_FREE C WHERE A.TABLESPACE_NAME=B.TABLESPACE_NAME AND A.TABLESPACE_NAME=C.TABLESPACE_NAME; 7、查看數(shù)據(jù)庫庫對(duì)象 select owner, object_type, status, count(*) count# from all_objects group by owner, object_type, status; 8、查看數(shù)據(jù)庫的版本 Select version FROM Product_component_version Where SUBSTR(PRODUCT,1,6)='Oracle'; 9、查看數(shù)據(jù)庫的創(chuàng)建日期和歸檔方式 Select Created, Log_Mode, Log_Mode From V$Database; 10、捕捉運(yùn)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。查看數(shù)據(jù)表的參數(shù)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.查看還沒提交的事務(wù)
select * from v$locked_object; select * from v$transaction; 13。查找object為哪些進(jìn)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$process p where s.paddr = p.addr and s.type = 'USER' and a.sid = s.sid and a.object='SUBSCRIBER_ATTR' order by s.username, s.osuser 14?；貪L段查看
select rownum, sys.dba_rollback_segs.segment_name Name, v$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。耗資源的進(jìn)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$process p where st.sid = s.sid and st.statistic# = to_number('38') and ('ALL' = 'ALL' or s.status = 'ALL') and p.addr = s.paddr order by st.value desc, p.spid asc, s.username asc, s.osuser asc 16。查看鎖（lock）情況
select /* RULE */ ls.osuser os_user_name, ls.username user_name, decode(ls.type, 'RW', 'Row wait enqueue lock', 'TM', 'DML enqueue lock', 'TX', 'Transaction enqueue lock', 'UL', 'User supplied lock') lock_type, o.object_name object, decode(ls.lmode, 1, null, 2, 'Row Share', 3, 'Row Exclusive', 4, 'Share', 5, 'Share Row Exclusive', 6, 'Exclusive', null) lock_mode, o.owner, ls.sid, ls.serial# serial_num, ls.id1, ls.id2 from sys.dba_objects o, ( select s.osuser, s.username, l.type, l.lmode, s.sid, s.serial#, l.id1, l.id2 from v$session s, v$lock l where s.sid = l.sid ) ls where o.object_id = ls.id1 and o.owner <> 'SYS' order by o.owner, o.object_name 17。查看等待（wait）情況
SELECT v$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$waitstat.count 18。查看sga情況
SELECT NAME, BYTES FROM SYS.V_$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$SQLAREA 21。查看object分類數(shù)量
select decode (o.type#,1,'INDEX' , 2,'TABLE' , 3 , 'CLUSTER' , 4, 'VIEW' , 5 , 'SYNONYM' , 6 , 'SEQUENCE' , 'OTHER' ) object_type , count(*) quantity from sys.obj$ 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。按用戶查看object種類
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。有關(guān)connection的相關(guān)信息
1）查看有哪些用戶連接 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）根據(jù)v.sid查看對(duì)應(yīng)連接的資源占用等情況 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）根據(jù)sid查看對(duì)應(yīng)連接正在運(yùn)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．查詢表空間使用情況select a.tablespace_name "表空間名稱",
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) "空閑(M)", round((a.bytes_alloc-nvl(b.bytes_free,0))/1024/1024,2) "使用(M)", Largest "最大擴(kuò)展段(M)", to_char(sysdate,'yyyy-mm-dd hh24:mi:ss') "采樣時(shí)間" 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. 查詢表空間的碎片程度
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.查看有哪些實(shí)例在運(yùn)行：
select * from v$active_instances;
12:15 PM | Add a comment | Permalink | Blog it | Oracle ORACLE性能調(diào)優(yōu)原則 數(shù)據(jù)庫的硬件配置：CPU、內(nèi)存、網(wǎng)絡(luò)條件 1. CPU：在任何機(jī)器中CPU的數(shù)據(jù)處理能力往往是衡量計(jì)算機(jī)性能的一個(gè)標(biāo)志，并且ORACLE是一個(gè)提供并行能力的數(shù)據(jù)庫系統(tǒng)，在CPU方面的要求就更高了，如果運(yùn)行隊(duì)列數(shù)目超過了CPU處理的數(shù)目，性能就會(huì)下降，我們要解決的問題就是要適當(dāng)增加CPU的數(shù)量了，當(dāng)然我們還可以將需要許多資源的進(jìn)程KILL掉； 2. 內(nèi)存：衡量機(jī)器性能的另外一個(gè)指標(biāo)就是內(nèi)存的多少了，在ORACLE中內(nèi)存和我們?cè)诮〝?shù)據(jù)庫中的交換區(qū)進(jìn)行數(shù)據(jù)的交換，讀數(shù)據(jù)時(shí)，磁盤I/O必須等待物 |
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