Oracle Error ORA-12850: Could not allocate slaves on all specified instances: string needed, string allocated

Oracle Error Message

ORA-12850: Could not allocate slaves on all specified instances: string needed, string allocated

Reason for the Error

When executing a query on a gv$ fixed view, one or more instances failed to allocate a slave to process query.

Solution

Check trace output for instances on which slaves failed to start. GV$ query can only proceed if slaves can be allocated on all instances.