一、oracle oracle服務(wù)器有Oracle instace 和Oracle database instance有memory structure 和 background process 組成。 memory structure包括shared pool、 SGA(System Global Area).
SGA包括：Database buffer cache 和 Redo log buffer cache. show sga; show parameter shared; show parameter db_cache; show parameter log; alter system set shared_pool_size=65M;
Process 包括User process、Server process、Background process; databasey有data file 和 log file 和 control file組成。
3、開啟和關(guān)閉數(shù)據(jù)庫 開啟數(shù)據(jù)庫Starting Up a Database shutdown、nomount、mount、open nomount——startup instance used to create db,create controlfile mount——open controlfile used to change log mode,rename file,db recovery... startup [nomount|mount|open] pfile= restrict recovery force
修改數(shù)據(jù)庫指令( alter database command) 1、改變數(shù)據(jù)庫從nomount狀態(tài)為mount； alter database db_01 mount; 2、打開一個只讀的數(shù)據(jù)庫 alter database db_01 open read only;
關(guān)閉數(shù)據(jù)庫Shutting Down the Database shutdown mode:normal、transactional、immediate、abort 4、監(jiān)視和使用diagnostic files alter log file——alertsid.log background tace file、use trace files
