oracle dba

[pande.dhiraj]

how many backgroud process in oracle database

[prabhu_81]

smon, pmon, dbw, lgwr,ckpt arcn these are the main background processes in oracle database

[susarlasireesha]

Oracle processes there are server and background processes.
background processes here's a list of background processes:
1.smon the system monitor carries out a crash recovery when a crashed insance is started up again. It also cleans temporary segments.
2. pmon the process monitor checks if a user process fails and if so, does all cleaning up of resources that the user process has aquired.
3.dbwr the database writer writes dirty blocks from the database buffer to the datafiles. How many dbwn processes are started is determined by the initialization parameter db_writer_processes. Dbwr also writes the actual scn with the block.
4. lgwr the log writer writes the redo log buffer from the sga to the online redo log file.
5. mman the memory manager
6. mrp managed recovery process: the process that applies archived redo log to the standby database.
7. rfs the remote file server process on the standby database receives archived redo logs from the primary database.
8.reco the distributed transaction recovery process finds pending (distributed) transaction and resolves them.
9. ckpt the checkpoint process reqularly initiates a checkpoint which uses dbwr to write all dirty blocks back to the datafiles, thus synchronizing the database. Since a checkpoint records the current scn, in a recovery only redo records with a scn higher than that of the last checkpoint need to be applied.
10.arch the archiver process archives redo log files if archivelog is enabled.
11.dnnn the dispatcher process is used in a shared server environment.
12, snnn the shared server process is used in a shared server environment.
13.lmon the lock manager. Lmd0 qmnn aq time manager
14. trwr trace writer
15.wmon the wakeup monitor process.
16. lcknnn inter-instance locking process.
17.snpnnn the snapshot process.
18.mmon new background process in oracle 10g.
19.dmon the data guard broker process.
20. snp the snapshot process.


background processes have v$session.type = 'background'