Note: The parameters on this screen impact the System Global Area (SGA) of your database. Each time an Oracle Database instance is started, the SGA is allocated in memory. The SGA is a group of shared memory structures that contain data and control information for one Oracle Database system. If multiple users are concurrently connected to the same database instance, the data in the SGA is shared among the users.
The default values that appear here for the SHARED_POOL_SIZE, DB_CACHE_SIZE, DB_BLOCK_SIZE, and PROCESSES parameters are based on the number of concurrent users and database environment type (OLTP, Data Warehousing, or Multipurpose) that you selected on previous screens.
Enter the size in bytes of the area for shared SQL and PL/SQL statements or accept the default entry. Large values improve performance in multi-user systems. Small values use less memory. This value is assigned to the initialization file parameter SHARED_POOL_SIZE.
Note: If you installed the Oracle Multimedia and Advanced Replication options, the value for Shared Pool Size must be at least 15 MB.
Enter the size in bytes for the database buffer cache. This is the portion of the SGA that holds copies of data blocks read from data files.The initialization parameter DB_CACHE_SIZE specifies the number of buffers in the database buffer cache. Each buffer in the cache is the size of one Oracle data block (which is specified by the initialization parameter DB_BLOCK_SIZE); therefore, each database buffer in the cache can hold a single data block read from a data file. All user processes concurrently connected to the instance share access to the database buffer cache.
Java pool memory is used in server memory for all session-specific Java code and data within the JVM. This value is assigned to the initialization file parameter JAVA_POOL_SIZE.
Enter the size in bytes for the large pool allocation heap. The Large Pool allocation heap is used by the Shared Server for session memory, by Parallel Execution for message buffers, and by Backup for disk I/O buffers. If LARGE_POOL_SIZE is left unset and the pool is required by parallel execution, then Oracle will compute a value automatically. The computation will add 250k per session for the shared server if MTS_DISPATCHERS is configured. A final computation will add a port-specific amount of memory for Backup I/O buffers.
Warning:this default computation can yield a size that is either too large to allocate or causes performance problems. In that case, you should set LARGE_POOL_SIZE to a number sufficiently small so that the database can start.
Shows the total physical RAM allocated for the database.
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