There are three major steps the Oracle instance goes through when you start the instance.
By submitting your personal information, you agree that TechTarget and its partners may contact you regarding relevant content, products and special offers.
- NOMOUNT stage
- MOUNT stage
- OPEN stage
In NOMOUNT stage, Oracle just reads the parameter file. This stage is normally used to create a control file or to create a database.
In MOUNT stage, Oracle reads the control file for the first time. Oracle also allocates the shared memory for the System Global Area (SGA) and also starts the background processes (SMON, PMON, LGWR, DBWR, etc.). This stage is typically used when performing recovery operations.
In the OPEN stage, Oracle accesses the database datafiles. At this point, users can connect to the instance and interact with the database. This is the normal stage of operations.
Dig Deeper on Oracle database backup and recovery
Related Q&A from Brian Peasland
Oracle expert Brian Peasland answers one reader's question about common pitfalls when connecting Oracle to outside programs.continue reading
One reader asks expert Brian Peasland a question about datafile sizes with the Oracle RMAN duplicate 10g command.continue reading
Managing parent table-child table relations in Oracle SQL environments is key to efficient programming.continue reading
Have a question for an expert?
Please add a title for your question
Get answers from a TechTarget expert on whatever's puzzling you.