ORACLE_MAINTAINED database users, part 2
Some time ago I wrote on ORACLE_MAINTAINED database users in Oracle 12c. Next question is: how are these users connected to database features and can the users be dropped – and if yes, how?
After installing a database with all options, you’ll get a long list of ORACLE_MAINTAINED users:
SQL> select username from dba_users where oracle_maintained='Y' order by 1; USERNAME ------------------------------ ANONYMOUS APEX_040200 APEX_PUBLIC_USER APPQOSSYS AUDSYS CTXSYS DBSNMP DIP DVF DVSYS FLOWS_FILES GSMADMIN_INTERNAL GSMCATUSER GSMUSER LBACSYS MDDATA MDSYS OJVMSYS OLAPSYS ORACLE_OCM ORDDATA ORDPLUGINS ORDSYS OUTLN SI_INFORMTN_SCHEMA SPATIAL_CSW_ADMIN_USR SPATIAL_WFS_ADMIN_USR SYS SYSBACKUP SYSDG SYSKM SYSTEM WMSYS XDB XS$NULL 35 rows selected.
The view DBA_REGISTRY provides some information how these users are connected to each other and to which feature they belong:
column comp_name format a35 column schema format a20 column other_schemas format a30 column username format a30 set linesize 120 set pagesize 50 SQL> select comp_name, schema, other_schemas from dba_registry;
COMP_NAME SCHEMA OTHER_SCHEMAS Oracle Application Express APEX_040200 FLOWS_FILES Oracle Label Security LBACSYS Oracle Database Vault DVSYS DVF Oracle Multimedia ORDSYS MDSYS,ORDDATA,ORDPLUGINS,SI_INFORMTN_SCHEMA Oracle Text CTXSYS Oracle Workspace Manager WMSYS Spatial MDSYS MDDATA,MDSYS,SPATIAL_CSW_ADMIN_USR,SPATIAL_WFS_ADMIN_USR Oracle XML Database XDB ANONYMOUS,XS$NULL Oracle Database Catalog Views SYS Oracle Database Packages and Types SYS APPQOSSYS,DBSNMP,DIP,GSMADMIN_INTERNAL,ORACLE_OCM,OUTLN,SYSTEM JServer JAVA Virtual Machine SYS Oracle XDK SYS Oracle Database Java Packages SYS OLAP Analytic Workspace SYS Oracle OLAP API SYS
More information on how these users are connected to featured can be found in Oracle 12c Security-Guide and in the support note “Oracle Created Database Users: Password, Usage and Files References (Doc ID 160861.1)”.
For Oracle 11g there’s a good overview on the website http://abcdba.com/abcdbaserver11gdefaultschema. You will find a list, how to safely remove a user. Please note the the commands are for Oracle 11g. The commands may have changed for Oracle 12c.
Helpful links:
- http://www.oaktable.net/content/dbausersoraclemaintained-12c
- https://de.wikibooks.org/wiki/Oracle:_Benutzerverwaltung
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