Sometimes You can get “TNS-12531: TNS:cannot allocate memory ” error.
Details of error are as follows.
TNS-12531: TNS:cannot allocate memory
This error is related with database server was a 32-Bit Windows machine where maximum 4G RAM can be utilized. Once all RAM is consumed.
Or Check hostname definition if it is different from the /etc/hosts file or not.
Do you want to learn more details about RMAN, then read the following articles.