ORA-01109: database not open

Today I got "ORA-01109: database not open" when trying to connect to RMAN catalog (In my case PDB "RCAT")
[code] [oracle@orcl19c admin]$ rman target sys/oracle@ORCL1 catalog RCATOWN/oracle@rcat Recovery Manager: Release 19.0.0.0.0 - Production on Sat Apr 25 02:05:25 2020 Version 19.3.0.0.0 Copyright (c) 1982, 2019, Oracle and/or its affiliates. All rights reserved. connected to target database: ORCL1 (DBID=1414679838) RMAN-00571: =========================================================== RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS =============== RMAN-00571: =========================================================== RMAN-00554: initialization of internal recovery manager package failed RMAN-04004: error from recovery catalog database: ORA-01109: database not open [/code]

First check your container database status (In my case RCAT)
[code] [oracle@orcl19c admin]$ sqlplus / as sysdba SQL*Plus: Release 19.0.0.0.0 - Production on Sat Apr 25 02:12:05 2020 Version 19.3.0.0.0 Copyright (c) 1982, 2019, Oracle. All rights reserved. Connected to: Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production Version 19.3.0.0.0 SQL> show con_name CON_NAME ------------------------------ CDB$ROOT SQL> SQL> col name format a20 SQL> col open_mode format a20 SQL> select name, open_mode from v$pdbs; NAME OPEN_MODE -------------------- -------------------- PDB$SEED READ ONLY ORCL1PDB MOUNTED PDB1 MOUNTED RCAT MOUNTED [/code]
In my case PDB RCAT in MOUNTED state. Connect to container database and open PDB RCAT
[code] SQL> alter session set container=RCAT; Session altered. SQL> alter pluggable database RCAT open; Pluggable database altered. SQL> select name, open_mode from v$pdbs; NAME OPEN_MODE -------------------- -------------------- RCAT READ WRITE [/code]

Now try to connect RMAN catalog
[code] [oracle@orcl19c admin]$ rman target sys/oracle@ORCL1 catalog RCATOWN/oracle@rcat Recovery Manager: Release 19.0.0.0.0 - Production on Sat Apr 25 02:13:49 2020 Version 19.3.0.0.0 Copyright (c) 1982, 2019, Oracle and/or its affiliates. All rights reserved. connected to target database: ORCL1 (DBID=1414679838) connected to recovery catalog database RMAN> exit Recovery Manager complete. [/code]