導讀:1建站知識ORACLE應用經驗(2)網站建設多少錢網站seo優化。

正在看的ORACLE教程是:ORACLE應用經驗(2)。------誰正在訪問數據庫?Select c.sid, c.serial#,c.username,a.object_id,b.object_name,c.program,c.status,d.name,c.osuser     from v$Locked_object a,     All_objects b,   &nb網站seo優化培訓sp; v$session c,     audit_actions dwhere a.object_id=b.object_id     and a.session_id =c.sid(+)     and c.command=d.action;alter system kill session '&1,&2';Select a.sid,a.serial#,a.username,a.status,a.program,b.name,a.osuserfrom v$session a,audit_actions b where a.command=b.actionAnd  username='&1';------誰被鎖住?Select a.sid,a.serial#,a.username,A.LOCKWAIT,a.status,a.program,b.namefrom v$session a,audit_actions b where a.command=b.actionAND LOCKWAIT IS NOT NULL;------誰在鎖表?Select a.sid,a.serial#,a.username,A.LOCKWAIT,a.status,a.program,b.namefrom v$session a,audit_actions b where a.command=b.actionAND STATUS='ACTIVE';Select sid, serial#, object_name, row_wait_block#,       row_wait_row#, row_wait_file#  from all_objects, v$sessionwhere row_wait_obj#=object_id and type='USER'       and lockwait is not null ;Select sl.username, sl.sid, sl.serial#  from v_$lock l1, v$session s1where exists (select * from v_$lock l2, v$session s2                where l2.sid=s2.sid and l2.id1=l1                  and s2.lockwait=l2.kaddr                  and request=0                  and l1.sid=s1.sid) ;select count(*) from v$session;select count(*) from sys.v_$process;select count(*) from sys.v_$transaction;ZYP_35.98------查看哪些包要固定COLUMN OWNER FORMAT A10Select owner, name, type,       source_size+cod網站seo優化診斷工具e_size+pars高端網站建設ed_size+error_size BYPES  from dba_object_sizewhere type='PACKAGE BODY' ORDER BY 4 DESC ;------查看一個用戶擁有哪些表空間的實體信息:Select tablespace_name, owner, segment_name,segment_type  from dba_segmentswhere owner-'SyS'       and segment_type_-'ROLLBACK'order by tablespace_name, owner, segment_name ;break on owner on segment_nameCOLUMN segment_name FORMAT A15cOLUMN tablespace_name FORMAT A15COLUMN file_name FORMAT A20SELECT A.owner, a.segment_name, b.tablespace_name, b.file_name,       sum(a.bytes) bytes  from dba_extents a, dba_data_files bwhere a.file_id-b.file_id group by a.owner, a.segment_name,       b.tablespace_name, b.file_name ;------看內存緩沖區使用效率的指數是命中率HITS:      Hits=Logical_reads/(logical_reads+physical_reads)其中：logical_reads=db_block_gets+consistent_readsselect cur.value db, con.value con, phy.value phy,       (cur.value+con.value)/cur.value+con.value+phy.value)*100 HITS  from v$sysstat cur, v$sysstat con, v$sysstat phywhere CUR.NAME='db block gets' AND       CON.NAME='consistent gets' AND       PHY.NAME='physical reads' ;------如何檢測ROLLBACK SEGMENT競爭?select class, count from v$waitstatwhere class in       ('system undo header', 'system undo block',        'undo header', 'undo block') ;select sum(value) from v$sysstat where name in       ('db block gets', 'consistents gets') ;    若count/sum(value)大于1%，則應考慮增加ROLLBACK SEGMENT------查看有事務在哪幾個回退段中：COLUMN u FORMAT A15COLUMN s FORMAT A15COLUMN s

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