| Property | Description |
|---|---|
| Parameter type | Big integer |
| Syntax | SGA_MAX_SIZE = integer [K | M | G] |
| Default value | Initial size of SGA at startup, dependent on the sizes of different pools in the SGA, such as buffer cache, shared pool, large pool, and so on. |
| Modifiable | No |
| Range of values | 0 to operating system-dependent |
SGA_MAX_SIZE specifies the maximum size of the SGA for the lifetime of the instance.
On 64-bit platforms and non-Windows 32-bit platforms, when either MEMORY_TARGET or MEMORY_MAX_TARGET is specified, the default value of SGA_MAX_SIZE is set to the larger of the two parameters. This causes more address space to be reserved for expansion of the SGA.
On Windows 32-bit platforms, the default value of SGA_MAX_SIZE is the largest of the following values:
60% of MEMORY_TARGET, if specified
60% of MEMORY_MAX_TARGET, if specified
25% of the total available virtual address space