I want to clone oracle 11g databases on the same machine and I need to change user etc. from e.g. PROD to DEV.

For that I use expdp/impdp, but this tends to be slow with increasing database size. I need to do this on linux and windows machines.

Is using expdp/impdp the fastest way to do this?

Or should I use a completly different way of doing this? i.e. do not use the same machine,

use two machines i.e. two separate oracle servers

or install multiple oracle servers on the same machine?

1 Answer 1


I prefer to use the RMAN clone method. The overall method is to start with the PROD database, and then a DEV database that is in a NOMOUNT state with all datafiles/controlfiles/tempfiles/archivelogs removed:

oracle> rman target sys@prod CATALOG rman/x@rman_catdb

RMAN> list backup;

  1    1399    53289602077 15-DEC-11 53289629964 15-DEC-11
  1    1400    53289629964 15-DEC-11 53289657925 15-DEC-11

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ ---------------
88      Full    20.52M     DISK        00:00:00     15-DEC-11
        BP Key: 88   Status: AVAILABLE  Compressed: NO  Tag: TAG20111215T133438
        Piece Name: /u01/backups/prod/PROD_20111215_c-4198857860-20111215-02
  SPFILE Included: Modification time: 15-DEC-11
  SPFILE db_unique_name: PROD
  Control File Included: Ckp SCN: 53295424420   Ckp time: 15-DEC-11

target database Password:
connected to target database: PROD (DBID=4198857860)

RMAN> connect auxiliary /

connected to auxiliary database: DEV (not mounted)

RMAN> run {
2> set until scn 53289602077;
3> duplicate target database to dev;
4> }

This gives me a block-for-block recreation of the production level database, and depending on how many threads you give RMAN, can be completed pretty quickly.

From there, I have a set of environment specific scripts I run that change passwords, null out email addresses, etc in the DEV database to configure it the way it needs to be.

  • I'm pretty noob on this. I know SQL and the basics of oracle administration. I'll look into RMAN - but could use any specifics I can get. Could you also post an example script to set passwords etc? Commented Sep 11, 2014 at 19:12
  • I have a script, called refresh_pwd.sql that I use on the file system. It literally just contains "alter user blah identified by pwd;" over and over again. Because it is a Dev DB, the passwords are common knowledge. Commented Sep 11, 2014 at 19:23
  • One other thing I forgot to mention, to do the RMAN clone you'll need to set some parameters in the DB before you put it in a NOMOUNT state: alter system set db_file_name_convert='+DATA/prod','+DATA/dev','+FRA/prod','+FRA/dev' scope=spfile; alter system set log_file_name_convert='+DATA/prod','+DATA/dev','+FRA/prod','+FRA/dev' scope=spfile; alter system set cluster_database=FALSE scope=spfile; Commented Sep 11, 2014 at 19:26

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