SHMTOTAL

The SHMTOTAL parameter places an absolute upper limit on the amount of shared memory that an instance of the database server can use. If SHMTOTAL is set to 0 or left unassigned, the database server continues to attach additional shared memory as needed until no virtual memory is available on the system.

You can usually leave SHMTOTAL set to 0 except in the following cases:

• You must limit the amount of virtual memory that the database server uses for other applications or other reasons.
• Your operating system runs out of swap space and performs abnormally.

In the latter case, you can set SHMTOTAL to a value that is a few megabytes less than the total swap space that is available on your computer.