Oracle® Database Reference 10g Release 2 (10.2) Part Number B14237-02 |
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Property | Description |
---|---|
Parameter type | Big integer |
Syntax | SGA_TARGET = integer [K | M | G] |
Default value | 0 (SGA autotuning is disabled) |
Modifiable | ALTER SYSTEM |
Range of values | 64 to operating system-dependent |
Basic | Yes |
SGA_TARGET
specifies the total size of all SGA components. If SGA_TARGET
is specified, then the following memory pools are automatically sized:
Buffer cache (DB_CACHE_SIZE
)
Shared pool (SHARED_POOL_SIZE
)
Large pool (LARGE_POOL_SIZE
)
Java pool (JAVA_POOL_SIZE
)
Streams pool (STREAMS_POOL_SIZE
)
If these automatically tuned memory pools are set to non-zero values, then those values are used as minimum levels by Automatic Shared Memory Management. You would set minimum values if an application component needs a minimum amount of memory to function properly.
The following pools are manually sized components and are not affected by Automatic Shared Memory Management:
Log buffer
Other buffer caches, such as KEEP
, RECYCLE
, and other block sizes
Fixed SGA and other internal allocations
The memory allocated to these pools is deducted from the total available for SGA_TARGET when Automatic Shared Memory Management computes the values of the automatically tuned memory pools.
See Also:
Oracle Database Concepts for information on automatic SGA management
Oracle Database Administrator's Guide for information on managing the SGA