Oracle in a Nutshell: A Desktop Quick Reference (In a Nutshell (O'Reilly))

by Rick Greenwald

Physical Files in an Oracle Database A tablespace is a logical view of the physical storage of information in an Oracle database. Three fundamental types of physical files make up an Oracle database: Control files Datafiles Redo log files

Db structure

The following sections describe the role of these three types of files and their interactions. Control Files The control file contains a list of all the other files that make up the database, such as the datafiles and redo log files. It also contains key information about the contents and state of the database, such as: The name of the database When the database was created The current state of the datafiles: whether they need recovery, are in a read-only state, and so on Whether the database closed cleanly the last time it was shut down The time period covered by each archived redo log What backups have been performed for the database

Control file

A transaction is defined as a single indivisible piece of work that affects some data.