Generation of "alter database rename file" scripts

I have written several blog posts where I generate "alter database rename file" statements using the familiar syntax

select 'alter database move datafile ''' || file_name || ''' TO ''' || replace(file_name,'old_sid','new_sid') || ''';'

Recently, an experienced co-worker showed me another version of the script which is, in my opinion, much simpler:

select 'alter database move datafile ' ||chr(39) || file_name || chr(39) || ' TO ' || chr(39) || replace(file_name,'old_sid','new_sid') || chr(39)|| ';'
from dba_data_files;

By referring to chr(39) instead of masking the char ' with the same character, your script becomes simpler to read and less error-prone. This will be particulary important as your scripts get more complex.

The same method can of course be applied when generating scripts for moving table partitions, indexes etc.

How to extract all datafile names without path using substr and instr functions

select trim(
            substr(file_name,
                (instr(file_name,'/', -1, 1) +1)
                )
               )  "file name"
from  dba_data_files;

Result:

file name
system01.dbf
sysaux01.dbf
undotbs01.dbf
users01.dbf
appl_data.dbf

How to extract all mountpoints for oracle data files in a database

To extract all unique mount points used for datafiles in a database, used the query below:

SELECT distinct SUBSTR(FILE_NAME, 1,
               INSTR(FILE_NAME, '/', -1, 1) --> Search for position of the first occurrence of the char '/', start at end of string
              -1) "PATH" --> starting from the rightmost side of the string, search from position found in INSTR above, and work your way to position 1
FROM DBA_DATA_FILES
;

Example output:

PATH
---------------------------------
/sales_db_02/oradata/SALES
/salesdb/oradata/SALES
/sales_db_01/oradata/SALES

If the database is in mount-mode (for example, a physical standby database), exchange dba_data_files with v$datafile:

 SELECT distinct SUBSTR(NAME, 1,
                   INSTR(NAME, '/', -1, 1)  
                  -1) "PATH" 
FROM v$datafile;

For logfiles, exchange dba_data_files with v$logfile and file_name with member:

  SELECT distinct SUBSTR(member, 1,
               INSTR(member, '/', -1, 1) 
              -1) "PATH" 
FROM v$logfile
;

Find duplicate file names

You can find duplicate file names, on different file systems, by using this query:

set lines 200
col "file_name" format a30
col "tablespace" format a30

set trimspool on
spool duplicates.lst
alter session set nls_language='american';

select t.name "tablespace",
trim(
            substr(f.name,
                (instr(f.name,'/', -1, 1) +1)
                )
               ) "file_name", count(*)
from v$datafile f join v$tablespace t
on (f.ts# = t.ts#)
group by t.name,
         trim(
            substr(f.name,
                (instr(f.name,'/', -1, 1) +1)
                )
               )
having count(*) > 1;



exit

How to move a datafile online in Oracle 12.1

Starting with Oracle 12.1, you can move datafiles online.


Generate move-script:

select 'alter database move datafile ''' || file_name || ''' TO ''' || replace(file_name,'old_sid','new_sid') || ''';'
from dba_data_files;

Output will be:

alter database move datafile '/oradata/old_sid/system01.dbf' TO '/oradata/new_sid/system01.dbf';

Create a tablespace using input variables

Here is a script to help set up tablespaces based on the path used for the system tablespace:

SET LINES 200
-- NEW_VALUE in sqlplus specifies a variable to hold a column value
COL tabspace_path FORMAT A50 NEW_VALUE path

SELECT SUBSTR(FILE_NAME, 1, INSTR(FILE_NAME, '/', -1) -1) tabspace_path
FROM DBA_DATA_FILES
WHERE TABLESPACE_NAME = 'SYSTEM';

SELECT '&path' variable_value
FROM DUAL;

CREATE BIGFILE TABLESPACE test_tbspc DATAFILE '&path/&tablespace_name..dbf' SIZE 32M AUTOEXTEND ON NEXT 8M MAXSIZE UNLIMITED
EXTENT MANAGEMENT LOCAL AUTOALLOCATE
SEGMENT SPACE MANAGEMENT AUTO;

exit

Run the script:

oracle@myserver:[testdb01]# sqlplus / as sysdba @test.sql

Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, OLAP and Data Mining options


TABSPACE_PATH
--------------------------------------------------
/u02/oradata/testdb01
old   1: SELECT '&path' variable_value
new   1: SELECT '/u02/oradata/testdb01' variable_value

VARIABLE_VALUE
---------------------
/u02/oradata/testdb01

Enter value for tablespace_name: mytablespace
old   1: CREATE BIGFILE TABLESPACE mytablespace DATAFILE '&path/&tablespace_name..dbf' SIZE 32M AUTOEXTEND ON NEXT 8M MAXSIZE UNLIMITED
new   1: CREATE BIGFILE TABLESPACE mytablespace DATAFILE '/u02/oradata/testdb01/mytablespace.dbf' SIZE 32M AUTOEXTEND ON NEXT 8M MAXSIZE UNLIMITED

Tablespace created.

Disconnected from Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, OLAP and Data Mining options

How to recreate the control file and rename the database and the datafiles

To change a database name or file names, it can be practical to recreate the control file, and in some cases your only option.

In this example, I will rename a database and its file structure from "OID11UI" to "OID11U1".

Start by generating a file which holds the current layout of all the database's files:

SQL> alter database backup controlfile to trace as '/u01/oracle/product/11204/dbs/cntr_trace.sql' resetlogs;

Database altered.

The generated file typically look like this:

STARTUP NOMOUNT
CREATE CONTROLFILE REUSE DATABASE "OID11UI" RESETLOGS  NOARCHIVELOG
    MAXLOGFILES 16
    MAXLOGMEMBERS 3
    MAXDATAFILES 100
    MAXINSTANCES 8
    MAXLOGHISTORY 292
LOGFILE
  GROUP 1 '/u02/oradata/OID11UI/redo01.log'  SIZE 50M BLOCKSIZE 512,
  GROUP 2 '/u02/oradata/OID11UI/redo02.log'  SIZE 50M BLOCKSIZE 512,
  GROUP 3 '/u02/oradata/OID11UI/redo03.log'  SIZE 50M BLOCKSIZE 512
-- STANDBY LOGFILE
DATAFILE
  '/u02/oradata/OID11UI/system01.dbf',
  '/u02/oradata/OID11UI/sysaux01.dbf',
  '/u02/oradata/OID11UI/undotbs01.dbf',
  '/u02/oradata/OID11UI/users01.dbf'
CHARACTER SET WE8MSWIN1252
;
-- Database can now be opened zeroing the online logs.
ALTER DATABASE OPEN RESETLOGS;
-- Commands to add tempfiles to temporary tablespaces.
-- Online tempfiles have complete space information.
-- Other tempfiles may require adjustment.
ALTER TABLESPACE TEMP ADD TEMPFILE '/u02/oradata/OID11UI/temp01.dbf'
     SIZE 20971520  REUSE AUTOEXTEND ON NEXT 655360  MAXSIZE 32767M;
-- End of tempfile additions.

Exchange the word "REUSE" against the word "SET":

CREATE CONTROLFILE SET DATABASE "OID11U1"

Optionally, on the first line, add a pointer to a correct parameter file:

STARTUP NOMOUNT PFILE='/u01/oracle/product/11204/dbs/initOID11U1.ora'

Change all references to "OID11UI" (the old name):

STARTUP NOMOUNT PFILE='/u01/oracle/product/11204/dbs/initOID11U1.ora'
CREATE CONTROLFILE SET DATABASE "OID11U1" RESETLOGS  NOARCHIVELOG
    MAXLOGFILES 16
    MAXLOGMEMBERS 3
    MAXDATAFILES 100
    MAXINSTANCES 8
    MAXLOGHISTORY 292
LOGFILE
  GROUP 1 '/u02/oradata/OID11U1/redo01.log'  SIZE 50M BLOCKSIZE 512,
  GROUP 2 '/u02/oradata/OID11U1/redo02.log'  SIZE 50M BLOCKSIZE 512,
  GROUP 3 '/u02/oradata/OID11U1/redo03.log'  SIZE 50M BLOCKSIZE 512
-- STANDBY LOGFILE
DATAFILE
  '/u02/oradata/OID11U1/system01.dbf',
  '/u02/oradata/OID11U1/sysaux01.dbf',
  '/u02/oradata/OID11U1/undotbs01.dbf',
  '/u02/oradata/OID11U1/users01.dbf'
CHARACTER SET WE8MSWIN1252
;
-- Database can now be opened zeroing the online logs.
ALTER DATABASE OPEN RESETLOGS;
-- Commands to add tempfiles to temporary tablespaces.
-- Online tempfiles have complete space information.
-- Other tempfiles may require adjustment.
ALTER TABLESPACE TEMP ADD TEMPFILE '/u02/oradata/OID11U1/temp01.dbf'
     SIZE 20971520  REUSE AUTOEXTEND ON NEXT 655360  MAXSIZE 32767M;
-- End of tempfile additions.

Change the folder name that oracle uses:

usu0oid01:OID11UI>cd /u02/oradata
usu0oid01:OID11UI>mv OID11UI OID11U1

Change the control_files directive in the parameter file:
Before

*.control_files='/u02/oradata/OID11UI/control01.ctl','/u02/oradata/OID11UI/control02.ctl'

After:

*.control_files='/u02/oradata/OID11U1/control01.ctl','/u02/oradata/OID11U1/control02.ctl'

Remove the old controlfiles physically from disk:

cd /u02/oradata/OID11U1
rm *.ctl

Shutdown the database:

SQL> shutdown abort
ORACLE instance shut down.

Change the oracle profile in the operating system:

cd
vi .profile

Before:

export ORACLE_SID=OID11UI

After:

export ORACLE_SID=OID11U1

Source the new profile, and check that the ORACLE_SID environmental variable is correctly set:

. .profile
usu0oid01:OID11U1>echo $ORACLE_SID
OID11U1

Start sqlplus and run script:

usu0oid01:OID11UI>sqlplus / as sysdba @cntr_trace.sql

SQL*Plus: Release 11.2.0.4.0 Production on Wed May 28 14:00:50 2014

Copyright (c) 1982, 2013, Oracle.  All rights reserved.

Connected to an idle instance.

ORACLE instance started.

Total System Global Area 1720328192 bytes
Fixed Size                  2247072 bytes
Variable Size            1107297888 bytes
Database Buffers          603979776 bytes
Redo Buffers                6803456 bytes

Control file created.

Database altered.

Tablespace altered.

SQL> select open_mode from v$database;

OPEN_MODE
--------------------
READ WRITE

Check the location of the data files after the change:

SQL> select file_name from dba_data_files union select member from v$logfile  union  select name from v$controlfile;

FILE_NAME
--------------------------------------------------
/u02/oradata/OID11U1/control01.ctl
/u02/oradata/OID11U1/control02.ctl
/u02/oradata/OID11U1/redo01.log
/u02/oradata/OID11U1/redo02.log
/u02/oradata/OID11U1/redo03.log
/u02/oradata/OID11U1/sysaux01.dbf
/u02/oradata/OID11U1/system01.dbf
/u02/oradata/OID11U1/undotbs01.dbf
/u02/oradata/OID11U1/users01.dbf

Lag en spfile (anbefales):

SQL> create spfile from pfile; 

File created.

SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.

Startup the database for normal use:

SQL> startup

How to exclude certain file systems when search for files belonging to tablespaces

Statement can be useful for example when reorganizing databases etc.


SELECT file_name FROM dba_data_files
WHERE file_name NOT LIKE '/data/oracle/u01%'
INTERSECT
SELECT file_name FROM dba_data_files
WHERE file_name NOT LIKE '/data/oracle/u02%';