SGA_TARGET Initialization Parameter

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.

Property                         Description

Parameter type                Big integer

Syntax  SGA_TARGET     integer [K | M | G]

Default value                     0 (SGA autotuning is disabled

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