ORA-03113: end-of-file on communication channel

Para solucionarlo, iniciaremos la base de datos en modo nomount con:

startup nomount

Y cambiaremos su estado a mount con:

alter database mount;

A continuación haremos un clear para cada grupo de archivelog de nuestra base de datos, ejecutando:

alter database clear unarchived logfile group 1;

alter database clear unarchived logfile group 2;

alter database clear unarchived logfile group 3; 

shutdown immediate;

Una vez detenida la iniciaremos de forma normal con el comando:

startup;

select status from v$instance;

VERIFICAR LAG DATAGUARD

SELECT ARCH.THREAD# "Thread", ARCH.SEQUENCE# "Last Sequence Received", APPL.SEQUENCE# "Last Sequence Applied", (ARCH.SEQUENCE# - APPL.SEQUENCE#) "Difference"FROM
(SELECT THREAD# ,SEQUENCE# FROM V$ARCHIVED_LOG WHERE (THREAD#,FIRST_TIME ) IN (SELECT THREAD#,MAX(FIRST_TIME) FROM V$ARCHIVED_LOG GROUP BY THREAD#)) ARCH,
(SELECT THREAD# ,SEQUENCE# FROM V$LOG_HISTORY WHERE (THREAD#,FIRST_TIME ) IN (SELECT THREAD#,MAX(FIRST_TIME) FROM V$LOG_HISTORY GROUP BY THREAD#)) APPL
WHERE ARCH.THREAD# = APPL.THREAD#
ORDER BY 1;