Renaming a Database

          Note: we cannot rename user.
How to rename a table?
syntax:
sql>RENAME <OLDNAME> TO <NEWNAME>;
SQL>CONN SCOTT/TIGER;
SQL>SELECT * FROM TAB;
SQL>RENAME DEPT TO DEPARTMENT;
RENAMED
How to rename a tablespace?
syntax:
sql>alter tablespace <oldtablespacename> rename to <newtablespacename>;
Note: we cannot rename the SYSTEM,SYSAUX tablespaces.
This feature is available from 10g onwards.
sql>connect /as sysdba
sql>show user
SYS
sql>select * from v$tablespace;
5 tablespaces it is showing
sql>alter tablespace userdata rename to test;
tablespace altered
sql>select * from v$tablespace;
It is renamed.
sql>alter tablespace test to userdata;
will try to alter system tablespace
---------------------------------
sql>alter tablespace system rename to systm;
cannot rename system tablespace.
How to rename a datafile or how to move datafile from current location
to new location?
steps:
step1: make the desired tablespace offline.
sql>alter tablespace userdata offline;
step2: GO to OS level, make a copy of the existing datafile to the
       new name and location.
]$ls
       userdata.dbf
]$cp userdata.dbf user.dbf or specify the path where u want to create.
step3:
       GO to database level
sql>alter tablespace userdata rename datafile '/home/prd/userdata.dbf'
             to '/home/prd/user.dbf';
step4:
      Make the tablespace online.
   sql>alter tablespace userdata online;
Practical Demo
sql>show user;
SYS
sql>select file_name,tablespace_name from dba_data_files;
sql>col FILE_NAME for a 25
sql>select file_name,tablespace_name from dba_data_files;
This will show what are the available tablespaces and the location.
sql>seleect tablespace_name ,status from dba_tablespaces;
This will show whether it is online or offline.
In offline mode we cannot access anything.
sql>alter tablespace userdata offline;
tablespace alterred
sql>select file_name,tablespace_name from dba_data_files;
now userdata is showing offline.
go to os level in prd folder
]$cd prd
prd]$ls
prd]$cp userdata.dbf user.dbf
prd]$cd
]$exit
sql>show user
SYS
sql>select file_name,tablespace_name from dba_data_files;
still name is same
sql>alter tablespace userdata rename datafile '/home/prd/userdata.dbf'
     to '/home/prd/user.dbf';
tablespace altered
sql>select file_name,tablespace_name from dba_data_files;
Now the datafile is modified to user.dbf
sql>seleect tablespace_name ,status from dba_tablespaces;
tablespace is still offline
sql>alter tablespace  userdata online;
go ot os level
prd]$rm userdata.dbf
 prd]$cd
$exit
sql>startup force; (bounce the database server)
sql>select name from v$datafile;
IInd method to rename a datafile:
---------------------------------
step1: select name from v$datafile;
     user.dbf
    --------
step2: shutdown the database preperly
      sql>shut immediate;
step3: go to os level make a copy of existing datafile to a new name
          and location
]$ls
       user.dbf
]$cp user.dbf userdata.dbf
step4:
     connect database as sysdba adn start the database in mount stage
    and then execute these commands
      sql>startup mount;
      sql>alter database rename
           file '/home/prd/user.dbf' to '/home/prd/userdata.dbf';
sql>alter database open;
sql>select name from v$datafile;
 It will  display all database files.
         userdata.dbf
Practical Demo
sql>select name from v$datafile;
it is showing 5 the last one is user.dbf
sql>shut immediate;
sql>host
go tp prd directory
prd]$ls
cp user.dbf userdata.dbf
prd]$cd
$exit
sql>show user;
SYS
sql>startup mount;
sql>select name from v$datafile;
sql>alter database rename '/home/prd/user.dbf' to '/home/prd/userdata.dbf';
How to rename a logfile?
Follow II way to rename a file.
sql>show user
SYS
sql>select member from v$logfile;
Member
-----------
/home/prd/redo1.log
/home/prd/redo2.log
sql>select group#,member from v$logfile;
sql>shut immediate;
sql>host
go to prd folder
prd]$cp redo1.lg redo1a.log (note: extension must be .log)
prd]$exit
sql>show user
SYS
sql>startup mount;
sql>select member from v$logfile;
old info.
sql>alter database rename
    file '/home/prd/redo1.log' to '/home/prd/redo1a.log';
database altered
sql>select member from v$logfile;
member
------
/home/prd/redo1a.log
/home/prd/redo2.log
sql>alter database open;
sql>select name from v$logfile;
memeber
----------
/home/prd/redo1a.log
/home/prd/redo2.log
 How to rename a database name?
Database name is there in pfile and controlfile.
sql>show parameter db_name;
         PRD
sql>select name from v$database;
         PRD
sql>alter database backup controlfile to trace;
Note: taking xerox copy of the control file.so text information will
         come so that we can edit and modify.
  oracle will take snapshot and keep it in udump directory.
 How do we know the udump location?
 sql>show parameter user_dump_dest;
     user related dump file is stored here.
    /home/prd/udump
 sql>shut immediate;
  sql>exit
      ]$
go to udump location
 ]$cd /home/prd/udump
udump]$ls -lrt
latest file will display at an end
 ---------.trc
 ]$vi ------.trc
      
       CREATE CONTROLFILE REUSE "PRD" NORESETLOGS  NOARCHIVELOG
                                                    OR ARCHIVELOG
       --------
      ----------
    CHARACTERSET US7ASCII;
      REPLACE REUSE WITH SET KEYWORD
      REPLACE DATABASENAME "PRD" WITH NEW DATABASENAME
     IN NORESETLOGS REMOVE NO
 :wq (save and exit)
---------------------------------------------------------------------------------------
 ]$cd /home/prd <enter>
  prd]$rm *.ctl
    
  note: while recreateing control file old control file is existing
         It will throw an error. so we have to remove existing control  file.
 prd]$cd $ORACLE_HOME/dbs
 prd]$ vi initprd.ora
                  here prd is the sidname or the instance name
        instance name and database name may be same or different
     db_name=TEST
     :wq (save and exit)
]$cd
]$sqlplus '/as sysdba'
sql>startup nomount;
sql>@/home/prd/udump/------.trc;
      control file is recreated
sql>alter database open resetlogs;
sql>select name from v$database;
    It will display new name
        
Practical Demo
sql> select name from v$database;
  name
 -------
 PRD
sql>show parameter db_anme;
        prd
sql>alter database backup controlfile to trace;
 database altered
sql> show parameter user_dump_dest;
                        /home/prd/udump
go to udump folder and check it
udump]$
if it is not generated execute again.
sql>shut immediate;
sql>exit
]$cd /home/prd/udump
udump]$ls -lrt
       select the last one
udump]$vi prd_ora_5991.trc
     dgg for removing the top portion
dd will command remove one by one
              go to insert mode
 :wq
]$cd
]$cd $ORACLE_HOME/dbs
dbs]$vi initprd.ora
 change db_name=TEST
:wq
Before removing control file take a backup
prd]$cp *.ctl ~  (taking backup into the /home directory)
prd]$rm *.ctl
prd]$ls
no control files
]$sqlplus '/as sysdba'
sql>startup nomount;
sql>@/home/prd/udump/prd_ora_5991.trc;
control file created
login as oracle user
#su - oracle
go to prd folder
prd]$ls
control1.ctl will exist
sql>alter database open resetlogs;
database altered
sql>select name from v$database;
TEST

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