一什么是ckpt进程 作用： 发出信号给dbwn 更新数据文件头 更新控制文件 at specific times, all modified databasebuffers in the system global area are written to the datafiles by dbwn. thisevent is called a checkpoint. the checkpoint process is
一  什么是ckpt进程 
        作用：
                发出信号给dbwn
                更新数据文件头
                更新控制文件
at specific times, all modified databasebuffers in the system global area are written to the datafiles by dbwn. thisevent is called a checkpoint. the checkpoint process is responsible forsignalling dbwn at checkpoints and updating all the datafiles and control filesof the database to indicate the most recent checkpoint.
二  操作示例[oracle@localhost 桌面]$ ps -ef | grep ora_oracle 6491 1 0 11:17 ? 00:00:00 ora_pmon_orcloracle 6493 1 0 11:17 ? 00:00:00 ora_psp0_orcloracle 6495 1 0 11:17 ? 00:00:00 ora_mman_orcloracle 6497 1 0 11:17 ? 00:00:00 ora_dbw0_orcloracle 6499 1 0 11:17 ? 00:00:00 ora_lgwr_orcloracle 6501 1 0 11:17 ? 00:00:00 ora_ckpt_orcloracle 6503 1 0 11:17 ? 00:00:00 ora_smon_orcloracle 6505 1 0 11:17 ? 00:00:00 ora_reco_orcloracle 6507 1 0 11:17 ? 00:00:00 ora_cjq0_orcloracle 6509 1 0 11:17 ? 00:00:00 ora_mmon_orcloracle 6511 1 0 11:17 ? 00:00:00 ora_mmnl_orcloracle 6513 1 0 11:17 ? 00:00:00 ora_d000_orcloracle 6515 1 0 11:17 ? 00:00:00 ora_s000_orcloracle 6519 1 0 11:17 ? 00:00:00 ora_qmnc_orcloracle 6527 1 0 11:18 ? 00:00:00 ora_q000_orcloracle 6529 1 0 11:18 ? 00:00:00 ora_q001_orcloracle 6538 1 0 11:19 ? 00:00:00 ora_j000_orcloracle 6541 2720 0 11:19 pts/0 00:00:00 grep ora_[oracle@localhost 桌面]$ ps -ef | grep ora_ | grep ckptoracle 6501 1 0 11:17 ? 00:00:00 ora_ckpt_orcl[oracle@localhost 桌面]$ kill -9 6501[oracle@localhost 桌面]$ ps -ef | grep ora_ | grep ckpt[oracle@localhost 桌面]$ ps -ef | grep ora_oracle 6554 2720 0 11:20 pts/0 00:00:00 grep ora_[oracle@localhost 桌面]$ sqlplus / as sysdba;sql*plus: release 10.2.0.1.0 - production on thu jun 6 11:20:14 2013copyright (c) 1982, 2005, oracle. all rights reserved.connected to an idle instance.sql> startuporacle instance started.total system global area 838860800 bytesfixed size 1222192 bytesvariable size 788531664 bytesdatabase buffers 46137344 bytesredo buffers 2969600 bytesdatabase mounted.database opened.sql> exit;disconnected from oracle database 10g enterprise edition release 10.2.0.1.0 - productionwith the partitioning, olap and data mining options[oracle@localhost 桌面]$ ps -ef | grep ora_ | grep ckptoracle 6568 1 0 11:20 ? 00:00:00 ora_ckpt_orcl
三  总结 
        1.ckpt，非常非常重要的后台进程，同样不能kill。触发顺序：ckpt------>dbwr------->lgwr
        2.作用：发出信号给dbwn、更新数据文件头、更新控制文件
        3.linux中使用ps命令查看ckpt进程。
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