ORA-27102: out of memory O/S-Error: (OS 1455)

ORA-27102: out of memory
 *Cause: Out of memory
 *Action: Consult the trace file for details

Solution is simple :

Increase the swap or decrease the memory parameters you gave.

To decrease memory parameters, follow these steps :

SQL -> Connected to idle instance.

SQL-> create pfile from spfile;

 (change parameter  in pfile)

SQL-> create spfile from pfile;

SQL-> startup;