1. Physical storage structure
1.1 data file
Data files are used to store all database data. Place the data in multiple data files, and then put the data files in different hard drives and increase access speeds.
1.2 record file
Record files are also known as a redo log (transaction) file. The redo log works in a loop in the log file. There is archive log mode and non-archive log mode.
1.3 parameter file
Every Oracle database and instance have its own unique init.ora file. The value in the init.ora file determines the characteristics of the database and instance.
1.4 control file
There must be at least one control file in each database, but it is recommended that the user uses two or more control files and stores on different disks. Control file is a very small file, which stores some
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Database All files related key information.
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The system maintains the integrity of the database by controlling files, as well as what to use when to restore data. In the case of losing all database control files,
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Provide a command to establish a control file, most of the cases can be used to rebuild the control file.
