oracle startup shutdown

database startup

instance creation
memory strucctures allocation
bg process
mount
instance will read ctl files
locate dbf and redo files
open
open the dbf and redo files
optional-:instance recovery
RECO will recover indoubt trx

sqlplus / as sysdba or sqlplus sys as sysdba (pssword)


sql> startup
sql> startup nomount.(only reates the instance)
used to modify control files

sql>alter database mount;(readint th ctl file and locating the files redo and data
use to rename datafile
enable/disable archivelogging redo
full db recovery


sql>alter database open;
options
restct mode ---dba's can log in
read only



shutdown database

1>flush buffer cache
close data/redo files
2>unmount
dis-associate instance from database
close the control files
3>shut down instance
release sga/memory structure
terminate bg process


shutdown <normal>---default
new connections are not allowed
oracle will wait for all current users get diconnected
write buffer caches (buffer pool and redo pool)
next starup will not require recover



shutdown trancsactional
no new tnx are allowed
disconects the user once the current tnx is over
write buffer caches (buffer pool and redo pool)
next starup will not require recover


shutdown ( immediate )
oracle will rollback the current tnx
write buffer caches (buffer pool and redo pool)
stops sql execution


shutdown abort
instace is terminated abruptly
write buffer caches not happens (buffer pool and redo pool)
next starup will require recover