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About Database Storage Structures

An Oracle database is madę up of physical and logical structures. Physical structures can be scen and operated on from the operating system, such as the physical files that storę data on a disk.

Logical structures are creatcd and recognizcd by Oracle Database and are not known to the operating system. The primary logical structurc in a database, a tablespace, contains physical files. The applications developcr or user may be aware of the logical structure, but is not usually aware of this physical structure. The database administrator (DBA) must understand the relationship between the physical and logical structures of a database.

Figurę 6-1 on page 6-2 shows the relationships between logical and physical structures. This figurę also shows recovery-related structures that are optionally kept in the fast recovery area. See "Fast Recovery Area" on page 9-5 for morę information.