_oracle system _ with the Church note 016-parameter file and database startup and shutdown

parameter file:spfile<sid>.ora dynamic parameter file, is a binary file, 9i later introduced and recommended to use Init<sid>.ora static parameter file, is a text file dynamic parameters, some parameters can be modified dynamically. It is recommended to use SPFile after 9i. database Startup Three stages:Nomount (launch instance based on parameter file configuration parameter) mount (opens control file according to the control file location recorded in the parameter file) open (opens the data file according to the control file information, redo the log file, Open database) Note: Nomount can create spfile based on Pfile before creating pfile from SPFile.

Create Pfile from Spfile;create spfile from Pfile;

database shutdown Four ways:abort (simulate a natural power outage, you need an instance recovery when you start the library again, the last thing to close the database in this way)immediate(all uncommitted things rolled back, forcing users to disconnect, Most commonly used) transactional (waiting for things to be automatically committed or rolled back, forcing disconnected users, rarely used) normal (default shutdown parameters, rarely used)