An Oracle database is a collection of data that treated as a unit. The purpose of a database is to store and retrieve related information.
History of Oracle Database
Oracle has a three decade history, it is founded in August 1977 by Larry Ellison, Bob Miner, Ed Oates and Bruce Scott.
1979 – Oracle release 2
1983 – Oracle release 3
1984 – Oracle release 4
1985 – Oracle release 5
1988 – Oracle release 6
1992 – Oracle release 7
1997 – Oracle release 8
1998 – Oracle release 8i
2001 – Oracle release 9i
2003 – Oracle release 10g
2007 – Oracle release 11g
2013 – Oracle release 12c
Database Storage Structure
Oracle database storage structure has three Storage Structures they are
- Logical Structure
- Physical Structure
- Memory Structure
It maps the data to the Physical structure and grained control of disk space use
A database is divided into logical storage units called table spaces. It’s the logical container for a segment and it consist of at least one data file.
A segment is a set of extents allocated for a user object, Such as table data…
An extent is a specific number of logically contiguous data blocks, obtained in a single allocation, Used to store a specific type of information
Oracle Database data is stored in data blocks. One data block corresponds to a specific number of bytes on disk
Schema and Schema Objects
Schema is a collection of logical database structures. Schema objects are user-created structures that directly refer to the data in the database.
Some Collection of databases
Oracle Database Process
Oracle database system has the following types of process
Client processes are created and maintained to run the software code of an application program. Most environments have separate computers for client processes.
Background processes asynchronously perform I/O and monitor other Oracle Database processes to provide increased parallelism for better performance and reliability.
Server processes communicate with client processes and interact with Oracle Database to fulfill requests.
Oracle processes include server processes and background processes. In most environments, Oracle processes and client processes run on separate computers.