a group of shared memory allocated by Oracle that contains data and control information for one Oracle database instance
See Shared Global Area.
An area of memory used for database information shared by the database users.
A group of shared memory structures that contain data and control information for an Oracle instance.
A shared storage area that contains information required by user processes and background processes, such as data and control information for one Oracle instance. The SGA is allocated when an Oracle instance is started, and is deallocated when the instance shuts down.
In an Oracle database, the SGA (System Global Area) is the part of the RAM used by the oracle processes. This part of memory is shared by all Oracle processes. All necessary information necessary for the instance operation are present here.