Undo段中區的狀態free expiredinactiveactive 顯示UNDO區信息 SELECT extent_ id, bytes, status FROM dba_ _undo_ _extentsWHERE segment_ name=' SYSSMU1S' ; 圖解一一個事務的操作流程 Undo段的組成:段頭、回滾塊 事務ID select xid, xidusn, xidslot, xidsqn, ubab1k, ubafil from vStransaction;事務表 undo段的第一一個 數據塊,每一個回滾段最多可以47個事務回滾段的段頭塊 select * from vSro1 lname; select header. block, header_ file from dba segments where segment_ _name='_ SYSSMU1S' ;alter system dump undo header,SYSSMU1S' :/轉儲回滾段頭Ialter system dump datafile 5 block 4308;//轉儲回滾段數據塊事務槽: xid、uba |
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select spid from v$process where addr in (select paddr from v$session where sid=(select sid from v$mystat where rownum=1)) ; |
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