oralce查看某张表占用空间大小
1、查询某用户下表使用大小的前10名
select * from (select a.segment_name,(bytes/(1024*1024)) sizez ,a.segment_type from dba_segments a where owner='risk' order by bytes desc ) where rownum <=10;
2、当使用drop table tablename 时,并没有完全删除,在数据库的回收站(recyclebin)中会保留一份。
查看:select * from recyclebin where type='TABLE' order by droptime desc;
使用purge关键字,从回收站中彻底删除 :
purge talbe "name"; 或者在删除表的时候使用:drop table tablename purge;
3、监控文件:v$controlfile;
4、日志文件(redo):v$logfile;
redo和undo:
redo->记录所有操作,用于恢复(redo records all the database transaction used for recovery)
undo->记录所有的前印象,用于回滚(undo is used to store uncommited data infor
used for rollback)