Add a Shared-Memory Segment

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Add a Shared-Memory Segment

Add a Shared-Memory Segment:
 
|-- -a--seg_size------------------------------------------------|

Element	Purpose	Key Considerations
-a seg_size	Allows you to add a new virtual shared-memory segment. Size is specified in kilobytes	Restrictions: The value of seg_size must be a positive integer. It must not exceed the operating-system limit on the size of shared-memory segments.

Ordinarily, you do not need to add segments to the virtual portion of shared memory because the database server automatically adds segments as they are needed. However, as segments are added, the database server might reach the operating-system limit for the maximum number of segments before it acquires the memory that it needs. This situation typically occurs when SHMADD is set so small that the database server exhausts the number of available segments before it acquires the memory that it needs for some operation.

If you manually add a segment that is larger than the segment specified by SHMADD, you can avoid exhausting the operating-system limit for segments but still meet the need that the database server has for additional memory.