Oracle : Ошибка ORA-12808

"cannot set %s_INSTANCES greater than number of instances %s"
*Cause: An attempt was made to set SCAN_INSTANCES or CACHE_INSTANCES
using the ALTER SYSTEM command to a value larger than the number
of available instances.
*Action: See the accompanying message for the current allowable
maximum value, or set SCAN_INSTANCES / CACHE_INSTANCES
to ALL.

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