L KiranKumar Reddy

• Sep 16th, 2011

 

Startup mount: This command is Usefull to bring the database into the mount state.This mode is Usefull for recovery of the database. in this mode only dba can access full database.
Startup nomount:This command is Usefull for two purpose.
1:To create A New database
2:To create new control file to the existing database

Janpreet Singh

• Oct 1st, 2011

 

Start nomount -- only alert log file is read
Startup mount -- alert log file and control file is read in sequence.

Dharma Teja

• Oct 10th, 2011

 

Nomount : Instance started
Mount : control file open for this instance
open : All the files open as described by the control file.

sriniv@s..

• May 14th, 2012

 

Start up No mount: instance started with help of parameter file & here control files are located.

Start up mount:database is mounted i.e control files are allocated & data files, redo logs are located.

Open: here allocated all data & redo logs.Now the database is ready to use.

pattiprashanth

 Profile Answers by pattiprashanth 

• Jul 8th, 2014

 

Startup NoMount: when you trigger "startup nomount".
oracle reads pfile/spfile parameters and view the controlfiles in this stage.

Startup Mount: when you trigger "startup mount".
oracle reads controlfile and check the contents are valid..
check names and locations of datafile and redologfile,DB Name, timestamp of the database of the database creation.In this stage database is ready to be opened. but it is not open in startup mount stage.

syed fahad

• Sep 13th, 2014

 

1) startup nomount :This will start the sga and background process(it will read pfile and spfile)
2) startup mount : This will only mount the datafile and controlfile locations...

AMRUTDHASKAT

• Feb 27th, 2015

 

At first,database is at rest. After startup nomount,Oracle 1st read parameter file,start background processes then allocate memory .
then it reads controlfile and take the database in mount state.

In between mount to open,if previous database was shutdown abnormally then Smon process start the roll forward operation and open the database & after opening the database smon performs the rollback operation(if previous database shutdown gracefully then oracle directly open the database from mount to open).

Sharif AlSiouri

• Mar 1st, 2015

 

Startup nnomount:
Oracle will read the initialization parameter file (SPfile or PFile) to allocate the memory structure ( SGA ) and to run the Background processes, this is used to create the database, and to recreate the SPfile and to recreate the Control file.

Startup Mount:
in this state the Oracle will be already in Nomount state then altered to Mount state, in this state the Controlfiles will be allocated and opened and read as their location is in the initialization parameter file, then oracle will read the control file which containing many critical information like : the location for the datafiles and the online redolog files.
some off when it is used when:
Renaming the datafile.
alter the database in archivelog mode
some recovery and backup steps.
and others