The entire process from Oracle software installation to running

The entire process from software installation to running in Oracle 1. When the software is just installed, there is only a bunch of software, and no database-related files and content are generated. 2. sqlplus/nolog connects to the database software without any specific database Association. At this time, there is no file or content related to the specific database. In this case, a server is generated. 3. create database this step uses the create database Command or OUI to create a database and generate relevant parameter files, control files, and data files. 4. startup nomount reads the parameter file, and creates an instance based on the content of the parameter file, including allocating SGA and starting background processes. At the same time, find the control file to prepare for the next step. The parameter file records the SGA size and allocation, and controls the file location, flash location, blocksize, and other information. In this case, the instance is in the started status and cannot start the database due to a control file error. 5. alter database mount reads the control file and finds the data file. In this case, the instance processes the mount status and can handle problems caused by data file errors. The control file records the correspondence between tablespaces and their data files. 6. The alter database open database is started successfully and the instance is in the open state.